LibMuJoCo API

mjContact

Fields

• dist: distance between nearest points; neg: penetration
• pos: position of contact point: midpoint between geoms
• frame: normal is in [0-2], points from geom[0] to geom[1]
• includemargin: include if dist<includemargin=margin-gap
• friction: tangent1, 2, spin, roll1, 2
• solref: constraint solver reference, normal direction
• solreffriction: constraint solver reference, friction directions
• solimp: constraint solver impedance
• mu: friction of regularized cone, set by mj_makeConstraint
• H: cone Hessian, set by mj_constraintUpdate
• dim: contact space dimensionality: 1, 3, 4 or 6
• geom1: id of geom 1; deprecated, use geom[0]
• geom2: id of geom 2; deprecated, use geom[1]
• geom: geom ids; -1 for flex
• flex: flex ids; -1 for geom
• elem: element ids; -1 for geom or flex vertex
• vert: vertex ids; -1 for geom or flex element
• exclude: 0: include, 1: in gap, 2: fused, 3: no dofs
• efc_address: address in efc; -1: not included

mjData

Fields

• narena: size of the arena in bytes (inclusive of the stack)
• nbuffer: size of main buffer in bytes
• nplugin: number of plugin instances
• pstack: first available mjtNum address in stack
• pbase: value of pstack when mj_markStack was last called
• parena: first available byte in arena
• maxuse_stack: maximum stack allocation in bytes
• maxuse_threadstack: maximum stack allocation per thread in bytes
• maxuse_arena: maximum arena allocation in bytes
• maxuse_con: maximum number of contacts
• maxuse_efc: maximum number of scalar constraints
• warning: warning statistics
• timer: timer statistics
• solver: solver statistics per island, per iteration
• solver_nisland: number of islands processed by solver
• solver_niter: number of solver iterations, per island
• solver_nnz: number of non-zeros in Hessian or efc_AR, per island
• solver_fwdinv: forward-inverse comparison: qfrc, efc
• ne: number of equality constraints
• nf: number of friction constraints
• nl: number of limit constraints
• nefc: number of constraints
• nnzJ: number of non-zeros in constraint Jacobian
• ncon: number of detected contacts
• nisland: number of detected constraint islands
• time: simulation time
• energy: potential, kinetic energy
• buffer: main buffer; all pointers point in it (nbuffer bytes)
• arena: arena+stack buffer (narena bytes)
• qpos: position (nq x 1)
• qvel: velocity (nv x 1)
• act: actuator activation (na x 1)
• qacc_warmstart: acceleration used for warmstart (nv x 1)
• plugin_state: plugin state (npluginstate x 1)
• ctrl: control (nu x 1)
• qfrc_applied: applied generalized force (nv x 1)
• xfrc_applied: applied Cartesian force/torque (nbody x 6)
• eq_active: enable/disable constraints (neq x 1)
• mocap_pos: positions of mocap bodies (nmocap x 3)
• mocap_quat: orientations of mocap bodies (nmocap x 4)
• qacc: acceleration (nv x 1)
• act_dot: time-derivative of actuator activation (na x 1)
• userdata: user data, not touched by engine (nuserdata x 1)
• sensordata: sensor data array (nsensordata x 1)
• plugin: copy of m->plugin, required for deletion (nplugin x 1)
• plugin_data: pointer to plugin-managed data structure (nplugin x 1)
• xpos: Cartesian position of body frame (nbody x 3)
• xquat: Cartesian orientation of body frame (nbody x 4)
• xmat: Cartesian orientation of body frame (nbody x 9)
• xipos: Cartesian position of body com (nbody x 3)
• ximat: Cartesian orientation of body inertia (nbody x 9)
• xanchor: Cartesian position of joint anchor (njnt x 3)
• xaxis: Cartesian joint axis (njnt x 3)
• geom_xpos: Cartesian geom position (ngeom x 3)
• geom_xmat: Cartesian geom orientation (ngeom x 9)
• site_xpos: Cartesian site position (nsite x 3)
• site_xmat: Cartesian site orientation (nsite x 9)
• cam_xpos: Cartesian camera position (ncam x 3)
• cam_xmat: Cartesian camera orientation (ncam x 9)
• light_xpos: Cartesian light position (nlight x 3)
• light_xdir: Cartesian light direction (nlight x 3)
• subtree_com: center of mass of each subtree (nbody x 3)
• cdof: com-based motion axis of each dof (rot:lin) (nv x 6)
• cinert: com-based body inertia and mass (nbody x 10)
• flexvert_xpos: Cartesian flex vertex positions (nflexvert x 3)
• flexelem_aabb: flex element bounding boxes (center, size) (nflexelem x 6)
• flexedge_J_rownnz: number of non-zeros in Jacobian row (nflexedge x 1)
• flexedge_J_rowadr: row start address in colind array (nflexedge x 1)
• flexedge_J_colind: column indices in sparse Jacobian (nflexedge x nv)
• flexedge_J: flex edge Jacobian (nflexedge x nv)
• flexedge_length: flex edge lengths (nflexedge x 1)
• ten_wrapadr: start address of tendon's path (ntendon x 1)
• ten_wrapnum: number of wrap points in path (ntendon x 1)
• ten_J_rownnz: number of non-zeros in Jacobian row (ntendon x 1)
• ten_J_rowadr: row start address in colind array (ntendon x 1)
• ten_J_colind: column indices in sparse Jacobian (ntendon x nv)
• ten_J: tendon Jacobian (ntendon x nv)
• ten_length: tendon lengths (ntendon x 1)
• wrap_obj: geom id; -1: site; -2: pulley (nwrap*2 x 1)
• wrap_xpos: Cartesian 3D points in all path (nwrap*2 x 3)
• actuator_length: actuator lengths (nu x 1)
• actuator_moment: actuator moments (nu x nv)
• crb: com-based composite inertia and mass (nbody x 10)
• qM: total inertia (sparse) (nM x 1)
• qLD: L'DL factorization of M (sparse) (nM x 1)
• qLDiagInv: 1/diag(D) (nv x 1)
• qLDiagSqrtInv: 1/sqrt(diag(D)) (nv x 1)
• bvh_aabb_dyn: global bounding box (center, size) (nbvhdynamic x 6)
• bvh_active: volume has been added to collisions (nbvh x 1)
• flexedge_velocity: flex edge velocities (nflexedge x 1)
• ten_velocity: tendon velocities (ntendon x 1)
• actuator_velocity: actuator velocities (nu x 1)
• cvel: com-based velocity (rot:lin) (nbody x 6)
• cdof_dot: time-derivative of cdof (rot:lin) (nv x 6)
• qfrc_bias: C(qpos,qvel) (nv x 1)
• qfrc_spring: passive spring force (nv x 1)
• qfrc_damper: passive damper force (nv x 1)
• qfrc_gravcomp: passive gravity compensation force (nv x 1)
• qfrc_fluid: passive fluid force (nv x 1)
• qfrc_passive: total passive force (nv x 1)
• subtree_linvel: linear velocity of subtree com (nbody x 3)
• subtree_angmom: angular momentum about subtree com (nbody x 3)
• qH: L'DL factorization of modified M (nM x 1)
• qHDiagInv: 1/diag(D) of modified M (nv x 1)
• D_rownnz: non-zeros in each row (nv x 1)
• D_rowadr: address of each row in D_colind (nv x 1)
• D_colind: column indices of non-zeros (nD x 1)
• B_rownnz: non-zeros in each row (nbody x 1)
• B_rowadr: address of each row in B_colind (nbody x 1)
• B_colind: column indices of non-zeros (nB x 1)
• qDeriv: d (passive + actuator - bias) / d qvel (nD x 1)
• qLU: sparse LU of (qM - dt*qDeriv) (nD x 1)
• actuator_force: actuator force in actuation space (nu x 1)
• qfrc_actuator: actuator force (nv x 1)
• qfrc_smooth: net unconstrained force (nv x 1)
• qacc_smooth: unconstrained acceleration (nv x 1)
• qfrc_constraint: constraint force (nv x 1)
• qfrc_inverse: net external force; should equal: (nv x 1)qfrcapplied + J'*xfrcapplied + qfrc_actuator
• cacc: com-based acceleration (nbody x 6)
• cfrc_int: com-based interaction force with parent (nbody x 6)
• cfrc_ext: com-based external force on body (nbody x 6)
• contact: list of all detected contacts (ncon x 1)
• efc_type: constraint type (mjtConstraint) (nefc x 1)
• efc_id: id of object of specified type (nefc x 1)
• efc_J_rownnz: number of non-zeros in constraint Jacobian row (nefc x 1)
• efc_J_rowadr: row start address in colind array (nefc x 1)
• efc_J_rowsuper: number of subsequent rows in supernode (nefc x 1)
• efc_J_colind: column indices in constraint Jacobian (nnzJ x 1)
• efc_JT_rownnz: number of non-zeros in constraint Jacobian row T (nv x 1)
• efc_JT_rowadr: row start address in colind array T (nv x 1)
• efc_JT_rowsuper: number of subsequent rows in supernode T (nv x 1)
• efc_JT_colind: column indices in constraint Jacobian T (nnzJ x 1)
• efc_J: constraint Jacobian (nnzJ x 1)
• efc_JT: constraint Jacobian transposed (nnzJ x 1)
• efc_pos: constraint position (equality, contact) (nefc x 1)
• efc_margin: inclusion margin (contact) (nefc x 1)
• efc_frictionloss: frictionloss (friction) (nefc x 1)
• efc_diagApprox: approximation to diagonal of A (nefc x 1)
• efc_KBIP: stiffness, damping, impedance, imp' (nefc x 4)
• efc_D: constraint mass (nefc x 1)
• efc_R: inverse constraint mass (nefc x 1)
• tendon_efcadr: first efc address involving tendon; -1: none (ntendon x 1)
• dof_island: island id of this dof; -1: none (nv x 1)
• island_dofnum: number of dofs in island (nisland x 1)
• island_dofadr: start address in island_dofind (nisland x 1)
• island_dofind: island dof indices; -1: none (nv x 1)
• dof_islandind: dof island indices; -1: none (nv x 1)
• efc_island: island id of this constraint (nefc x 1)
• island_efcnum: number of constraints in island (nisland x 1)
• island_efcadr: start address in island_efcind (nisland x 1)
• island_efcind: island constraint indices (nefc x 1)
• efc_AR_rownnz: number of non-zeros in AR (nefc x 1)
• efc_AR_rowadr: row start address in colind array (nefc x 1)
• efc_AR_colind: column indices in sparse AR (nefc x nefc)
• efc_AR: Jinv(M)J' + R (nefc x nefc)
• efc_vel: velocity in constraint space: J*qvel (nefc x 1)
• efc_aref: reference pseudo-acceleration (nefc x 1)
• efc_b: linear cost term: J*qacc_smooth - aref (nefc x 1)
• efc_force: constraint force in constraint space (nefc x 1)
• efc_state: constraint state (mjtConstraintState) (nefc x 1)
• threadpool: ThreadPool for multithreaded operations

mjLROpt

Fields

• mode: which actuators to process (mjtLRMode)
• useexisting: use existing length range if available
• uselimit: use joint and tendon limits if available
• accel: target acceleration used to compute force
• maxforce: maximum force; 0: no limit
• timeconst: time constant for velocity reduction; min 0.01
• timestep: simulation timestep; 0: use mjOption.timestep
• inttotal: total simulation time interval
• interval: evaluation time interval (at the end)
• tolrange: convergence tolerance (relative to range)

mjModel

Fields

• nq: number of generalized coordinates = dim(qpos)
• nv: number of degrees of freedom = dim(qvel)
• nu: number of actuators/controls = dim(ctrl)
• na: number of activation states = dim(act)
• nbody: number of bodies
• nbvh: number of total bounding volumes in all bodies
• nbvhstatic: number of static bounding volumes (aabb stored in mjModel)
• nbvhdynamic: number of dynamic bounding volumes (aabb stored in mjData)
• njnt: number of joints
• ngeom: number of geoms
• nsite: number of sites
• ncam: number of cameras
• nlight: number of lights
• nflex: number of flexes
• nflexvert: number of vertices in all flexes
• nflexedge: number of edges in all flexes
• nflexelem: number of elements in all flexes
• nflexelemdata: number of element vertex ids in all flexes
• nflexshelldata: number of shell fragment vertex ids in all flexes
• nflexevpair: number of element-vertex pairs in all flexes
• nflextexcoord: number of vertices with texture coordinates
• nmesh: number of meshes
• nmeshvert: number of vertices in all meshes
• nmeshnormal: number of normals in all meshes
• nmeshtexcoord: number of texcoords in all meshes
• nmeshface: number of triangular faces in all meshes
• nmeshgraph: number of ints in mesh auxiliary data
• nskin: number of skins
• nskinvert: number of vertices in all skins
• nskintexvert: number of vertiex with texcoords in all skins
• nskinface: number of triangular faces in all skins
• nskinbone: number of bones in all skins
• nskinbonevert: number of vertices in all skin bones
• nhfield: number of heightfields
• nhfielddata: number of data points in all heightfields
• ntex: number of textures
• ntexdata: number of bytes in texture rgb data
• nmat: number of materials
• npair: number of predefined geom pairs
• nexclude: number of excluded geom pairs
• neq: number of equality constraints
• ntendon: number of tendons
• nwrap: number of wrap objects in all tendon paths
• nsensor: number of sensors
• nnumeric: number of numeric custom fields
• nnumericdata: number of mjtNums in all numeric fields
• ntext: number of text custom fields
• ntextdata: number of mjtBytes in all text fields
• ntuple: number of tuple custom fields
• ntupledata: number of objects in all tuple fields
• nkey: number of keyframes
• nmocap: number of mocap bodies
• nplugin: number of plugin instances
• npluginattr: number of chars in all plugin config attributes
• nuser_body: number of mjtNums in body_user
• nuser_jnt: number of mjtNums in jnt_user
• nuser_geom: number of mjtNums in geom_user
• nuser_site: number of mjtNums in site_user
• nuser_cam: number of mjtNums in cam_user
• nuser_tendon: number of mjtNums in tendon_user
• nuser_actuator: number of mjtNums in actuator_user
• nuser_sensor: number of mjtNums in sensor_user
• nnames: number of chars in all names
• nnames_map: number of slots in the names hash map
• npaths: number of chars in all paths
• nM: number of non-zeros in sparse inertia matrix
• nD: number of non-zeros in sparse dof-dof matrix
• nB: number of non-zeros in sparse body-dof matrix
• ntree: number of kinematic trees under world body
• ngravcomp: number of bodies with nonzero gravcomp
• nemax: number of potential equality-constraint rows
• njmax: number of available rows in constraint Jacobian
• nconmax: number of potential contacts in contact list
• nuserdata: number of mjtNums reserved for the user
• nsensordata: number of mjtNums in sensor data vector
• npluginstate: number of mjtNums in plugin state vector
• narena: number of bytes in the mjData arena (inclusive of stack)
• nbuffer: number of bytes in buffer
• opt: physics options
• vis: visualization options
• stat: model statistics
• buffer: main buffer; all pointers point in it (nbuffer)
• qpos0: qpos values at default pose (nq x 1)
• qpos_spring: reference pose for springs (nq x 1)
• body_parentid: id of body's parent (nbody x 1)
• body_rootid: id of root above body (nbody x 1)
• body_weldid: id of body that this body is welded to (nbody x 1)
• body_mocapid: id of mocap data; -1: none (nbody x 1)
• body_jntnum: number of joints for this body (nbody x 1)
• body_jntadr: start addr of joints; -1: no joints (nbody x 1)
• body_dofnum: number of motion degrees of freedom (nbody x 1)
• body_dofadr: start addr of dofs; -1: no dofs (nbody x 1)
• body_treeid: id of body's kinematic tree; -1: static (nbody x 1)
• body_geomnum: number of geoms (nbody x 1)
• body_geomadr: start addr of geoms; -1: no geoms (nbody x 1)
• body_simple: 1: diag M; 2: diag M, sliders only (nbody x 1)
• body_sameframe: inertial frame is same as body frame (nbody x 1)
• body_pos: position offset rel. to parent body (nbody x 3)
• body_quat: orientation offset rel. to parent body (nbody x 4)
• body_ipos: local position of center of mass (nbody x 3)
• body_iquat: local orientation of inertia ellipsoid (nbody x 4)
• body_mass: mass (nbody x 1)
• body_subtreemass: mass of subtree starting at this body (nbody x 1)
• body_inertia: diagonal inertia in ipos/iquat frame (nbody x 3)
• body_invweight0: mean inv inert in qpos0 (trn, rot) (nbody x 2)
• body_gravcomp: antigravity force, units of body weight (nbody x 1)
• body_margin: MAX over all geom margins (nbody x 1)
• body_user: user data (nbody x nuser_body)
• body_plugin: plugin instance id; -1: not in use (nbody x 1)
• body_contype: OR over all geom contypes (nbody x 1)
• body_conaffinity: OR over all geom conaffinities (nbody x 1)
• body_bvhadr: address of bvh root (nbody x 1)
• body_bvhnum: number of bounding volumes (nbody x 1)
• bvh_depth: depth in the bounding volume hierarchy (nbvh x 1)
• bvh_child: left and right children in tree (nbvh x 2)
• bvh_nodeid: geom or elem id of node; -1: non-leaf (nbvh x 1)
• bvh_aabb: local bounding box (center, size) (nbvhstatic x 6)
• jnt_type: type of joint (mjtJoint) (njnt x 1)
• jnt_qposadr: start addr in 'qpos' for joint's data (njnt x 1)
• jnt_dofadr: start addr in 'qvel' for joint's data (njnt x 1)
• jnt_bodyid: id of joint's body (njnt x 1)
• jnt_group: group for visibility (njnt x 1)
• jnt_limited: does joint have limits (njnt x 1)
• jnt_actfrclimited: does joint have actuator force limits (njnt x 1)
• jnt_actgravcomp: is gravcomp force applied via actuators (njnt x 1)
• jnt_solref: constraint solver reference: limit (njnt x mjNREF)
• jnt_solimp: constraint solver impedance: limit (njnt x mjNIMP)
• jnt_pos: local anchor position (njnt x 3)
• jnt_axis: local joint axis (njnt x 3)
• jnt_stiffness: stiffness coefficient (njnt x 1)
• jnt_range: joint limits (njnt x 2)
• jnt_actfrcrange: range of total actuator force (njnt x 2)
• jnt_margin: min distance for limit detection (njnt x 1)
• jnt_user: user data (njnt x nuser_jnt)
• dof_bodyid: id of dof's body (nv x 1)
• dof_jntid: id of dof's joint (nv x 1)
• dof_parentid: id of dof's parent; -1: none (nv x 1)
• dof_treeid: id of dof's kinematic tree (nv x 1)
• dof_Madr: dof address in M-diagonal (nv x 1)
• dof_simplenum: number of consecutive simple dofs (nv x 1)
• dof_solref: constraint solver reference:frictionloss (nv x mjNREF)
• dof_solimp: constraint solver impedance:frictionloss (nv x mjNIMP)
• dof_frictionloss: dof friction loss (nv x 1)
• dof_armature: dof armature inertia/mass (nv x 1)
• dof_damping: damping coefficient (nv x 1)
• dof_invweight0: diag. inverse inertia in qpos0 (nv x 1)
• dof_M0: diag. inertia in qpos0 (nv x 1)
• geom_type: geometric type (mjtGeom) (ngeom x 1)
• geom_contype: geom contact type (ngeom x 1)
• geom_conaffinity: geom contact affinity (ngeom x 1)
• geom_condim: contact dimensionality (1, 3, 4, 6) (ngeom x 1)
• geom_bodyid: id of geom's body (ngeom x 1)
• geom_dataid: id of geom's mesh/hfield; -1: none (ngeom x 1)
• geom_matid: material id for rendering; -1: none (ngeom x 1)
• geom_group: group for visibility (ngeom x 1)
• geom_priority: geom contact priority (ngeom x 1)
• geom_plugin: plugin instance id; -1: not in use (ngeom x 1)
• geom_sameframe: same as body frame (1) or iframe (2) (ngeom x 1)
• geom_solmix: mixing coef for solref/imp in geom pair (ngeom x 1)
• geom_solref: constraint solver reference: contact (ngeom x mjNREF)
• geom_solimp: constraint solver impedance: contact (ngeom x mjNIMP)
• geom_size: geom-specific size parameters (ngeom x 3)
• geom_aabb: bounding box, (center, size) (ngeom x 6)
• geom_rbound: radius of bounding sphere (ngeom x 1)
• geom_pos: local position offset rel. to body (ngeom x 3)
• geom_quat: local orientation offset rel. to body (ngeom x 4)
• geom_friction: friction for (slide, spin, roll) (ngeom x 3)
• geom_margin: detect contact if dist<margin(ngeom x 1)
• geom_gap: include in solver if dist<margin-gap (ngeom x 1)
• geom_fluid: fluid interaction parameters (ngeom x mjNFLUID)
• geom_user: user data (ngeom x nuser_geom)
• geom_rgba: rgba when material is omitted (ngeom x 4)
• site_type: geom type for rendering (mjtGeom) (nsite x 1)
• site_bodyid: id of site's body (nsite x 1)
• site_matid: material id for rendering; -1: none (nsite x 1)
• site_group: group for visibility (nsite x 1)
• site_sameframe: same as body frame (1) or iframe (2) (nsite x 1)
• site_size: geom size for rendering (nsite x 3)
• site_pos: local position offset rel. to body (nsite x 3)
• site_quat: local orientation offset rel. to body (nsite x 4)
• site_user: user data (nsite x nuser_site)
• site_rgba: rgba when material is omitted (nsite x 4)
• cam_mode: camera tracking mode (mjtCamLight) (ncam x 1)
• cam_bodyid: id of camera's body (ncam x 1)
• cam_targetbodyid: id of targeted body; -1: none (ncam x 1)
• cam_pos: position rel. to body frame (ncam x 3)
• cam_quat: orientation rel. to body frame (ncam x 4)
• cam_poscom0: global position rel. to sub-com in qpos0 (ncam x 3)
• cam_pos0: global position rel. to body in qpos0 (ncam x 3)
• cam_mat0: global orientation in qpos0 (ncam x 9)
• cam_resolution: [width, height] in pixels (ncam x 2)
• cam_fovy: y-field of view (deg) (ncam x 1)
• cam_intrinsic: focal length; principal point
• cam_sensorsize: sensor size (ncam x 2)
• cam_ipd: inter-pupilary distance (ncam x 1)
• cam_user: user data (ncam x nuser_cam)
• light_mode: light tracking mode (mjtCamLight) (nlight x 1)
• light_bodyid: id of light's body (nlight x 1)
• light_targetbodyid: id of targeted body; -1: none (nlight x 1)
• light_directional: directional light (nlight x 1)
• light_castshadow: does light cast shadows (nlight x 1)
• light_bulbradius: light radius for soft shadows (nlight x 1)
• light_active: is light on (nlight x 1)
• light_pos: position rel. to body frame (nlight x 3)
• light_dir: direction rel. to body frame (nlight x 3)
• light_poscom0: global position rel. to sub-com in qpos0 (nlight x 3)
• light_pos0: global position rel. to body in qpos0 (nlight x 3)
• light_dir0: global direction in qpos0 (nlight x 3)
• light_attenuation: OpenGL attenuation (quadratic model) (nlight x 3)
• light_cutoff: OpenGL cutoff (nlight x 1)
• light_exponent: OpenGL exponent (nlight x 1)
• light_ambient: ambient rgb (alpha=1) (nlight x 3)
• light_diffuse: diffuse rgb (alpha=1) (nlight x 3)
• light_specular: specular rgb (alpha=1) (nlight x 3)
• flex_contype: flex contact type (nflex x 1)
• flex_conaffinity: flex contact affinity (nflex x 1)
• flex_condim: contact dimensionality (1, 3, 4, 6) (nflex x 1)
• flex_priority: flex contact priority (nflex x 1)
• flex_solmix: mix coef for solref/imp in contact pair (nflex x 1)
• flex_solref: constraint solver reference: contact (nflex x mjNREF)
• flex_solimp: constraint solver impedance: contact (nflex x mjNIMP)
• flex_friction: friction for (slide, spin, roll) (nflex x 3)
• flex_margin: detect contact if dist<margin(nflex x 1)
• flex_gap: include in solver if dist<margin-gap (nflex x 1)
• flex_internal: internal flex collision enabled (nflex x 1)
• flex_selfcollide: self collision mode (mjtFlexSelf) (nflex x 1)
• flex_activelayers: number of active element layers, 3D only (nflex x 1)
• flex_dim: 1: lines, 2: triangles, 3: tetrahedra (nflex x 1)
• flex_matid: material id for rendering (nflex x 1)
• flex_group: group for visibility (nflex x 1)
• flex_vertadr: first vertex address (nflex x 1)
• flex_vertnum: number of vertices (nflex x 1)
• flex_edgeadr: first edge address (nflex x 1)
• flex_edgenum: number of edges (nflex x 1)
• flex_elemadr: first element address (nflex x 1)
• flex_elemnum: number of elements (nflex x 1)
• flex_elemdataadr: first element vertex id address (nflex x 1)
• flex_shellnum: number of shells (nflex x 1)
• flex_shelldataadr: first shell data address (nflex x 1)
• flex_evpairadr: first evpair address (nflex x 1)
• flex_evpairnum: number of evpairs (nflex x 1)
• flex_texcoordadr: address in flex_texcoord; -1: none (nflex x 1)
• flex_vertbodyid: vertex body ids (nflexvert x 1)
• flex_edge: edge vertex ids (2 per edge) (nflexedge x 2)
• flex_elem: element vertex ids (dim+1 per elem) (nflexelemdata x 1)
• flex_elemlayer: element distance from surface, 3D only (nflexelem x 1)
• flex_shell: shell fragment vertex ids (dim per frag) (nflexshelldata x 1)
• flex_evpair: (element, vertex) collision pairs (nflexevpair x 2)
• flex_vert: vertex positions in local body frames (nflexvert x 3)
• flex_xvert0: Cartesian vertex positions in qpos0 (nflexvert x 3)
• flexedge_length0: edge lengths in qpos0 (nflexedge x 1)
• flexedge_invweight0: edge inv. weight in qpos0 (nflexedge x 1)
• flex_radius: radius around primitive element (nflex x 1)
• flex_edgestiffness: edge stiffness (nflex x 1)
• flex_edgedamping: edge damping (nflex x 1)
• flex_edgeequality: is edge equality constraint defined (nflex x 1)
• flex_rigid: are all verices in the same body (nflex x 1)
• flexedge_rigid: are both edge vertices in same body (nflexedge x 1)
• flex_centered: are all vertex coordinates (0,0,0) (nflex x 1)
• flex_flatskin: render flex skin with flat shading (nflex x 1)
• flex_bvhadr: address of bvh root; -1: no bvh (nflex x 1)
• flex_bvhnum: number of bounding volumes (nflex x 1)
• flex_rgba: rgba when material is omitted (nflex x 4)
• flex_texcoord: vertex texture coordinates (nflextexcoord x 2)
• mesh_vertadr: first vertex address (nmesh x 1)
• mesh_vertnum: number of vertices (nmesh x 1)
• mesh_faceadr: first face address (nmesh x 1)
• mesh_facenum: number of faces (nmesh x 1)
• mesh_bvhadr: address of bvh root (nmesh x 1)
• mesh_bvhnum: number of bvh (nmesh x 1)
• mesh_normaladr: first normal address (nmesh x 1)
• mesh_normalnum: number of normals (nmesh x 1)
• mesh_texcoordadr: texcoord data address; -1: no texcoord (nmesh x 1)
• mesh_texcoordnum: number of texcoord (nmesh x 1)
• mesh_graphadr: graph data address; -1: no graph (nmesh x 1)
• mesh_vert: vertex positions for all meshes (nmeshvert x 3)
• mesh_normal: normals for all meshes (nmeshnormal x 3)
• mesh_texcoord: vertex texcoords for all meshes (nmeshtexcoord x 2)
• mesh_face: vertex face data (nmeshface x 3)
• mesh_facenormal: normal face data (nmeshface x 3)
• mesh_facetexcoord: texture face data (nmeshface x 3)
• mesh_graph: convex graph data (nmeshgraph x 1)
• mesh_scale: scaling applied to asset vertices (nmesh x 3)
• mesh_pos: translation applied to asset vertices (nmesh x 3)
• mesh_quat: rotation applied to asset vertices (nmesh x 4)
• mesh_pathadr: address of asset path for mesh; -1: none (nmesh x 1)
• skin_matid: skin material id; -1: none (nskin x 1)
• skin_group: group for visibility (nskin x 1)
• skin_rgba: skin rgba (nskin x 4)
• skin_inflate: inflate skin in normal direction (nskin x 1)
• skin_vertadr: first vertex address (nskin x 1)
• skin_vertnum: number of vertices (nskin x 1)
• skin_texcoordadr: texcoord data address; -1: no texcoord (nskin x 1)
• skin_faceadr: first face address (nskin x 1)
• skin_facenum: number of faces (nskin x 1)
• skin_boneadr: first bone in skin (nskin x 1)
• skin_bonenum: number of bones in skin (nskin x 1)
• skin_vert: vertex positions for all skin meshes (nskinvert x 3)
• skin_texcoord: vertex texcoords for all skin meshes (nskintexvert x 2)
• skin_face: triangle faces for all skin meshes (nskinface x 3)
• skin_bonevertadr: first vertex in each bone (nskinbone x 1)
• skin_bonevertnum: number of vertices in each bone (nskinbone x 1)
• skin_bonebindpos: bind pos of each bone (nskinbone x 3)
• skin_bonebindquat: bind quat of each bone (nskinbone x 4)
• skin_bonebodyid: body id of each bone (nskinbone x 1)
• skin_bonevertid: mesh ids of vertices in each bone (nskinbonevert x 1)
• skin_bonevertweight: weights of vertices in each bone (nskinbonevert x 1)
• skin_pathadr: address of asset path for skin; -1: none (nskin x 1)
• hfield_size: (x, y, ztop, zbottom) (nhfield x 4)
• hfield_nrow: number of rows in grid (nhfield x 1)
• hfield_ncol: number of columns in grid (nhfield x 1)
• hfield_adr: address in hfield_data (nhfield x 1)
• hfield_data: elevation data (nhfielddata x 1)
• hfield_pathadr: address of hfield asset path; -1: none (nhfield x 1)
• tex_type: texture type (mjtTexture) (ntex x 1)
• tex_height: number of rows in texture image (ntex x 1)
• tex_width: number of columns in texture image (ntex x 1)
• tex_adr: address in rgb (ntex x 1)
• tex_rgb: rgb (alpha = 1) (ntexdata x 1)
• tex_pathadr: address of texture asset path; -1: none (ntex x 1)
• mat_texid: texture id; -1: none (nmat x 1)
• mat_texuniform: make texture cube uniform (nmat x 1)
• mat_texrepeat: texture repetition for 2d mapping (nmat x 2)
• mat_emission: emission (x rgb) (nmat x 1)
• mat_specular: specular (x white) (nmat x 1)
• mat_shininess: shininess coef (nmat x 1)
• mat_reflectance: reflectance (0: disable) (nmat x 1)
• mat_metallic: metallic coef (nmat x 1)
• mat_roughness: roughness coef (nmat x 1)
• mat_rgba: rgba (nmat x 4)
• pair_dim: contact dimensionality (npair x 1)
• pair_geom1: id of geom1 (npair x 1)
• pair_geom2: id of geom2 (npair x 1)
• pair_signature: body1<<16 + body2 (npair x 1)
• pair_solref: solver reference: contact normal (npair x mjNREF)
• pair_solreffriction: solver reference: contact friction (npair x mjNREF)
• pair_solimp: solver impedance: contact (npair x mjNIMP)
• pair_margin: detect contact if dist<margin(npair x 1)
• pair_gap: include in solver if dist<margin-gap (npair x 1)
• pair_friction: tangent1, 2, spin, roll1, 2 (npair x 5)
• exclude_signature: body1<<16 + body2 (nexclude x 1)
• eq_type: constraint type (mjtEq) (neq x 1)
• eq_obj1id: id of object 1 (neq x 1)
• eq_obj2id: id of object 2 (neq x 1)
• eq_active0: initial enable/disable constraint state (neq x 1)
• eq_solref: constraint solver reference (neq x mjNREF)
• eq_solimp: constraint solver impedance (neq x mjNIMP)
• eq_data: numeric data for constraint (neq x mjNEQDATA)
• tendon_adr: address of first object in tendon's path (ntendon x 1)
• tendon_num: number of objects in tendon's path (ntendon x 1)
• tendon_matid: material id for rendering (ntendon x 1)
• tendon_group: group for visibility (ntendon x 1)
• tendon_limited: does tendon have length limits (ntendon x 1)
• tendon_width: width for rendering (ntendon x 1)
• tendon_solref_lim: constraint solver reference: limit (ntendon x mjNREF)
• tendon_solimp_lim: constraint solver impedance: limit (ntendon x mjNIMP)
• tendon_solref_fri: constraint solver reference: friction (ntendon x mjNREF)
• tendon_solimp_fri: constraint solver impedance: friction (ntendon x mjNIMP)
• tendon_range: tendon length limits (ntendon x 2)
• tendon_margin: min distance for limit detection (ntendon x 1)
• tendon_stiffness: stiffness coefficient (ntendon x 1)
• tendon_damping: damping coefficient (ntendon x 1)
• tendon_frictionloss: loss due to friction (ntendon x 1)
• tendon_lengthspring: spring resting length range (ntendon x 2)
• tendon_length0: tendon length in qpos0 (ntendon x 1)
• tendon_invweight0: inv. weight in qpos0 (ntendon x 1)
• tendon_user: user data (ntendon x nuser_tendon)
• tendon_rgba: rgba when material is omitted (ntendon x 4)
• wrap_type: wrap object type (mjtWrap) (nwrap x 1)
• wrap_objid: object id: geom, site, joint (nwrap x 1)
• wrap_prm: divisor, joint coef, or site id (nwrap x 1)
• actuator_trntype: transmission type (mjtTrn) (nu x 1)
• actuator_dyntype: dynamics type (mjtDyn) (nu x 1)
• actuator_gaintype: gain type (mjtGain) (nu x 1)
• actuator_biastype: bias type (mjtBias) (nu x 1)
• actuator_trnid: transmission id: joint, tendon, site (nu x 2)
• actuator_actadr: first activation address; -1: stateless (nu x 1)
• actuator_actnum: number of activation variables (nu x 1)
• actuator_group: group for visibility (nu x 1)
• actuator_ctrllimited: is control limited (nu x 1)
• actuator_forcelimited: is force limited (nu x 1)
• actuator_actlimited: is activation limited (nu x 1)
• actuator_dynprm: dynamics parameters (nu x mjNDYN)
• actuator_gainprm: gain parameters (nu x mjNGAIN)
• actuator_biasprm: bias parameters (nu x mjNBIAS)
• actuator_actearly: step activation before force (nu x 1)
• actuator_ctrlrange: range of controls (nu x 2)
• actuator_forcerange: range of forces (nu x 2)
• actuator_actrange: range of activations (nu x 2)
• actuator_gear: scale length and transmitted force (nu x 6)
• actuator_cranklength: crank length for slider-crank (nu x 1)
• actuator_acc0: acceleration from unit force in qpos0 (nu x 1)
• actuator_length0: actuator length in qpos0 (nu x 1)
• actuator_lengthrange: feasible actuator length range (nu x 2)
• actuator_user: user data (nu x nuser_actuator)
• actuator_plugin: plugin instance id; -1: not a plugin (nu x 1)
• sensor_type: sensor type (mjtSensor) (nsensor x 1)
• sensor_datatype: numeric data type (mjtDataType) (nsensor x 1)
• sensor_needstage: required compute stage (mjtStage) (nsensor x 1)
• sensor_objtype: type of sensorized object (mjtObj) (nsensor x 1)
• sensor_objid: id of sensorized object (nsensor x 1)
• sensor_reftype: type of reference frame (mjtObj) (nsensor x 1)
• sensor_refid: id of reference frame; -1: global frame (nsensor x 1)
• sensor_dim: number of scalar outputs (nsensor x 1)
• sensor_adr: address in sensor array (nsensor x 1)
• sensor_cutoff: cutoff for real and positive; 0: ignore (nsensor x 1)
• sensor_noise: noise standard deviation (nsensor x 1)
• sensor_user: user data (nsensor x nuser_sensor)
• sensor_plugin: plugin instance id; -1: not a plugin (nsensor x 1)
• plugin: globally registered plugin slot number (nplugin x 1)
• plugin_stateadr: address in the plugin state array (nplugin x 1)
• plugin_statenum: number of states in the plugin instance (nplugin x 1)
• plugin_attr: config attributes of plugin instances (npluginattr x 1)
• plugin_attradr: address to each instance's config attrib (nplugin x 1)
• numeric_adr: address of field in numeric_data (nnumeric x 1)
• numeric_size: size of numeric field (nnumeric x 1)
• numeric_data: array of all numeric fields (nnumericdata x 1)
• text_adr: address of text in text_data (ntext x 1)
• text_size: size of text field (strlen+1) (ntext x 1)
• text_data: array of all text fields (0-terminated) (ntextdata x 1)
• tuple_adr: address of text in text_data (ntuple x 1)
• tuple_size: number of objects in tuple (ntuple x 1)
• tuple_objtype: array of object types in all tuples (ntupledata x 1)
• tuple_objid: array of object ids in all tuples (ntupledata x 1)
• tuple_objprm: array of object params in all tuples (ntupledata x 1)
• key_time: key time (nkey x 1)
• key_qpos: key position (nkey x nq)
• key_qvel: key velocity (nkey x nv)
• key_act: key activation (nkey x na)
• key_mpos: key mocap position (nkey x 3*nmocap)
• key_mquat: key mocap quaternion (nkey x 4*nmocap)
• key_ctrl: key control (nkey x nu)
• name_bodyadr: body name pointers (nbody x 1)
• name_jntadr: joint name pointers (njnt x 1)
• name_geomadr: geom name pointers (ngeom x 1)
• name_siteadr: site name pointers (nsite x 1)
• name_camadr: camera name pointers (ncam x 1)
• name_lightadr: light name pointers (nlight x 1)
• name_flexadr: flex name pointers (nflex x 1)
• name_meshadr: mesh name pointers (nmesh x 1)
• name_skinadr: skin name pointers (nskin x 1)
• name_hfieldadr: hfield name pointers (nhfield x 1)
• name_texadr: texture name pointers (ntex x 1)
• name_matadr: material name pointers (nmat x 1)
• name_pairadr: geom pair name pointers (npair x 1)
• name_excludeadr: exclude name pointers (nexclude x 1)
• name_eqadr: equality constraint name pointers (neq x 1)
• name_tendonadr: tendon name pointers (ntendon x 1)
• name_actuatoradr: actuator name pointers (nu x 1)
• name_sensoradr: sensor name pointers (nsensor x 1)
• name_numericadr: numeric name pointers (nnumeric x 1)
• name_textadr: text name pointers (ntext x 1)
• name_tupleadr: tuple name pointers (ntuple x 1)
• name_keyadr: keyframe name pointers (nkey x 1)
• name_pluginadr: plugin instance name pointers (nplugin x 1)
• names: names of all objects, 0-terminated (nnames x 1)
• names_map: internal hash map of names (nnames_map x 1)
• paths: paths to assets, 0-terminated (npaths x 1)

mjOption

Fields

• timestep: timestep
• apirate: update rate for remote API (Hz)
• impratio: ratio of friction-to-normal contact impedance
• tolerance: main solver tolerance
• ls_tolerance: CG/Newton linesearch tolerance
• noslip_tolerance: noslip solver tolerance
• mpr_tolerance: MPR solver tolerance
• gravity: gravitational acceleration
• wind: wind (for lift, drag and viscosity)
• magnetic: global magnetic flux
• density: density of medium
• viscosity: viscosity of medium
• o_margin: margin
• o_solref: solref
• o_solimp: solimp
• o_friction: friction
• integrator: integration mode (mjtIntegrator)
• cone: type of friction cone (mjtCone)
• jacobian: type of Jacobian (mjtJacobian)
• solver: solver algorithm (mjtSolver)
• iterations: maximum number of main solver iterations
• ls_iterations: maximum number of CG/Newton linesearch iterations
• noslip_iterations: maximum number of noslip solver iterations
• mpr_iterations: maximum number of MPR solver iterations
• disableflags: bit flags for disabling standard features
• enableflags: bit flags for enabling optional features
• disableactuator: bit flags for disabling actuators by group id
• sdf_initpoints: number of starting points for gradient descent
• sdf_iterations: max number of iterations for gradient descent

mjSolverStat

Fields

• improvement: cost reduction, scaled by 1/trace(M(qpos0))
• gradient: gradient norm (primal only, scaled)
• lineslope: slope in linesearch
• nactive: number of active constraints
• nchange: number of constraint state changes
• neval: number of cost evaluations in line search
• nupdate: number of Cholesky updates in line search

mjStatistic

Fields

• meaninertia: mean diagonal inertia
• meanmass: mean body mass
• meansize: mean body size
• extent: spatial extent
• center: center of model

mjTask

Fields

• func: pointer to the function that implements the task
• args: arguments to func
• status: status of the task

mjThreadPool

Fields

• nworker: number of workers in the pool

mjTimerStat

Fields

• duration: cumulative duration
• number: how many times was timer called

mjUI

Fields

• spacing: UI theme spacing
• color: UI theme color
• predicate: callback to set item state programmatically
• userdata: pointer to user data (passed to predicate)
• rectid: index of this ui rectangle in mjuiState
• auxid: aux buffer index of this ui
• radiocol: number of radio columns (0 defaults to 2)
• width: width
• height: current heigth
• maxheight: height when all sections open
• scroll: scroll from top of UI
• mousesect: 0: none, -1: scroll, otherwise 1+section
• mouseitem: item within section
• mousehelp: help button down: print shortcuts
• editsect: 0: none, otherwise 1+section
• edititem: item within section
• editcursor: cursor position
• editscroll: horizontal scroll
• edittext: current text
• editchanged: pointer to changed edit in last mjui_event
• nsect: number of sections in use
• sect: preallocated array of sections

mjVFS

Fields

• nfile: number of files present
• filename: file name without path
• filesize: file size in bytes
• filedata: buffer with file data
• filestamp: checksum of the file data

mjVisual

mjWarningStat

Fields

• lastinfo: info from last warning
• number: how many times was warning raised

mjrContext

Fields

• lineWidth: line width for wireframe rendering
• shadowClip: clipping radius for directional lights
• shadowScale: fraction of light cutoff for spot lights
• fogStart: fog start = stat.extent * vis.map.fogstart
• fogEnd: fog end = stat.extent * vis.map.fogend
• fogRGBA: fog rgba
• shadowSize: size of shadow map texture
• offWidth: width of offscreen buffer
• offHeight: height of offscreen buffer
• offSamples: number of offscreen buffer multisamples
• fontScale: font scale
• auxWidth: auxiliary buffer width
• auxHeight: auxiliary buffer height
• auxSamples: auxiliary buffer multisamples
• offFBO: offscreen framebuffer object
• offFBO_r: offscreen framebuffer for resolving multisamples
• offColor: offscreen color buffer
• offColor_r: offscreen color buffer for resolving multisamples
• offDepthStencil: offscreen depth and stencil buffer
• offDepthStencil_r: offscreen depth and stencil buffer for resolving multisamples
• shadowFBO: shadow map framebuffer object
• shadowTex: shadow map texture
• auxFBO: auxiliary framebuffer object
• auxFBO_r: auxiliary framebuffer object for resolving
• auxColor: auxiliary color buffer
• auxColor_r: auxiliary color buffer for resolving
• ntexture: number of allocated textures
• textureType: type of texture (mjtTexture) (ntexture)
• texture: texture names
• basePlane: all planes from model
• baseMesh: all meshes from model
• baseHField: all hfields from model
• baseBuiltin: all buildin geoms, with quality from model
• baseFontNormal: normal font
• baseFontShadow: shadow font
• baseFontBig: big font
• rangePlane: all planes from model
• rangeMesh: all meshes from model
• rangeHField: all hfields from model
• rangeBuiltin: all builtin geoms, with quality from model
• rangeFont: all characters in font
• nskin: number of skins
• skinvertVBO: skin vertex position VBOs (nskin)
• skinnormalVBO: skin vertex normal VBOs (nskin)
• skintexcoordVBO: skin vertex texture coordinate VBOs (nskin)
• skinfaceVBO: skin face index VBOs (nskin)
• charWidth: character widths: normal and shadow
• charWidthBig: chacarter widths: big
• charHeight: character heights: normal and shadow
• charHeightBig: character heights: big
• glInitialized: is OpenGL initialized
• windowAvailable: is default/window framebuffer available
• windowSamples: number of samples for default/window framebuffer
• windowStereo: is stereo available for default/window framebuffer
• windowDoublebuffer: is default/window framebuffer double buffered
• currentBuffer: currently active framebuffer: mjFBWINDOW or mjFBOFFSCREEN
• readPixelFormat: default color pixel format for mjr_readPixels
• readDepthMap: depth mapping: mjDEPTHZERONEAR or mjDEPTHZEROFAR

mjrRect

Fields

• left: left (usually 0)
• bottom: bottom (usually 0)
• width: width (usually buffer width)
• height: height (usually buffer height)

mjuiDef

Fields

• type: type (mjtItem); -1: section
• name: name
• state: state
• pdata: pointer to data
• other: string with type-specific properties

mjuiItem

Fields

• type: type (mjtItem)
• name: name
• state: 0: disable, 1: enable, 2+: use predicate
• pdata: data pointer (type-specific)
• sectionid: id of section containing item
• itemid: id of item within section
• rect: rectangle occupied by item

mjuiSection

Fields

• name: name
• state: 0: closed, 1: open
• modifier: 0: none, 1: control, 2: shift; 4: alt
• shortcut: shortcut key; 0: undefined
• nitem: number of items in use
• item: preallocated array of items
• rtitle: rectangle occupied by title
• rcontent: rectangle occupied by content

mjuiState

Fields

• nrect: number of rectangles used
• rect: rectangles (index 0: entire window)
• userdata: pointer to user data (for callbacks)
• type: (type mjtEvent)
• left: is left button down
• right: is right button down
• middle: is middle button down
• doubleclick: is last press a double click
• button: which button was pressed (mjtButton)
• buttontime: time of last button press
• x: x position
• y: y position
• dx: x displacement
• dy: y displacement
• sx: x scroll
• sy: y scroll
• control: is control down
• shift: is shift down
• alt: is alt down
• key: which key was pressed
• keytime: time of last key press
• mouserect: which rectangle contains mouse
• dragrect: which rectangle is dragged with mouse
• dragbutton: which button started drag (mjtButton)
• dropcount: number of files dropped
• droppaths: paths to files dropped

mjuiThemeColor

Fields

• master: master background
• thumb: scrollbar thumb
• secttitle: section title
• sectfont: section font
• sectsymbol: section symbol
• sectpane: section pane
• shortcut: shortcut background
• fontactive: font active
• fontinactive: font inactive
• decorinactive: decor inactive
• decorinactive2: inactive slider color 2
• button: button
• check: check
• radio: radio
• select: select
• select2: select pane
• slider: slider
• slider2: slider color 2
• edit: edit
• edit2: edit invalid
• cursor: edit cursor

mjuiThemeSpacing

Fields

• total: total width
• scroll: scrollbar width
• label: label width
• section: section gap
• itemside: item side gap
• itemmid: item middle gap
• itemver: item vertical gap
• texthor: text horizontal gap
• textver: text vertical gap
• linescroll: number of pixels to scroll
• samples: number of multisamples

mjvCamera

Fields

• type: camera type (mjtCamera)
• fixedcamid: fixed camera id
• trackbodyid: body id to track
• lookat: lookat point
• distance: distance to lookat point or tracked body
• azimuth: camera azimuth (deg)
• elevation: camera elevation (deg)

mjvFigure

Fields

• flg_legend: show legend
• flg_ticklabel: show grid tick labels (x,y)
• flg_extend: automatically extend axis ranges to fit data
• flg_barplot: isolated line segments (i.e. GL_LINES)
• flg_selection: vertical selection line
• flg_symmetric: symmetric y-axis
• linewidth: line width
• gridwidth: grid line width
• gridsize: number of grid points in (x,y)
• gridrgb: grid line rgb
• figurergba: figure color and alpha
• panergba: pane color and alpha
• legendrgba: legend color and alpha
• textrgb: text color
• linergb: line colors
• range: axis ranges; (min>=max) automatic
• xformat: x-tick label format for sprintf
• yformat: y-tick label format for sprintf
• minwidth: string used to determine min y-tick width
• title: figure title; subplots separated with 2+ spaces
• xlabel: x-axis label
• linename: line names for legend
• legendoffset: number of lines to offset legend
• subplot: selected subplot (for title rendering)
• highlight: if point is in legend rect, highlight line
• highlightid: if id>=0 and no point, highlight id
• selection: selection line x-value
• linepnt: number of points in line; (0) disable
• linedata: line data (x,y)
• xaxispixel: range of x-axis in pixels
• yaxispixel: range of y-axis in pixels
• xaxisdata: range of x-axis in data units
• yaxisdata: range of y-axis in data units

mjvGLCamera

Fields

• pos: position
• forward: forward direction
• up: up direction
• frustum_center: hor. center (left,right set to match aspect)
• frustum_width: width (not used for rendering)
• frustum_bottom: bottom
• frustum_top: top
• frustum_near: near
• frustum_far: far

mjvGeom

Fields

• type: geom type (mjtGeom)
• dataid: mesh, hfield or plane id; -1: none
• objtype: mujoco object type; mjOBJ_UNKNOWN for decor
• objid: mujoco object id; -1 for decor
• category: visual category
• texid: texture id; -1: no texture
• texuniform: uniform cube mapping
• texcoord: mesh or flex geom has texture coordinates
• segid: segmentation id; -1: not shown
• texrepeat: texture repetition for 2D mapping
• size: size parameters
• pos: Cartesian position
• mat: Cartesian orientation
• rgba: color and transparency
• emission: emission coef
• specular: specular coef
• shininess: shininess coef
• reflectance: reflectance coef
• label: text label
• camdist: distance to camera (used by sorter)
• modelrbound: geom rbound from model, 0 if not model geom
• transparent: treat geom as transparent

mjvLight

Fields

• pos: position rel. to body frame
• dir: direction rel. to body frame
• attenuation: OpenGL attenuation (quadratic model)
• cutoff: OpenGL cutoff
• exponent: OpenGL exponent
• ambient: ambient rgb (alpha=1)
• diffuse: diffuse rgb (alpha=1)
• specular: specular rgb (alpha=1)
• headlight: headlight
• directional: directional light
• castshadow: does light cast shadows
• bulbradius: bulb radius for soft shadows

mjvOption

Fields

• label: what objects to label (mjtLabel)
• frame: which frame to show (mjtFrame)
• geomgroup: geom visualization by group
• sitegroup: site visualization by group
• jointgroup: joint visualization by group
• tendongroup: tendon visualization by group
• actuatorgroup: actuator visualization by group
• flexgroup: flex visualization by group
• skingroup: skin visualization by group
• flags: visualization flags (indexed by mjtVisFlag)
• bvh_depth: depth of the bounding volume hierarchy to be visualized
• flex_layer: element layer to be visualized for 3D flex

mjvPerturb

Fields

• select: selected body id; non-positive: none
• flexselect: selected flex id; negative: none
• skinselect: selected skin id; negative: none
• active: perturbation bitmask (mjtPertBit)
• active2: secondary perturbation bitmask (mjtPertBit)
• refpos: reference position for selected object
• refquat: reference orientation for selected object
• refselpos: reference position for selection point
• localpos: selection point in object coordinates
• localmass: spatial inertia at selection point
• scale: relative mouse motion-to-space scaling (set by initPerturb)

mjvSceneState

Fields

• nbuffer: size of the buffer in bytes
• buffer: heap-allocated memory for all arrays in this struct
• maxgeom: maximum number of mjvGeom supported by this state object
• scratch: scratch space for vis geoms inserted by the user and plugins

mjvScene

Fields

• maxgeom: size of allocated geom buffer
• ngeom: number of geoms currently in buffer
• geoms: buffer for geoms (ngeom)
• geomorder: buffer for ordering geoms by distance to camera (ngeom)
• nflex: number of flexes
• flexedgeadr: address of flex edges (nflex)
• flexedgenum: number of edges in flex (nflex)
• flexvertadr: address of flex vertices (nflex)
• flexvertnum: number of vertices in flex (nflex)
• flexfaceadr: address of flex faces (nflex)
• flexfacenum: number of flex faces allocated (nflex)
• flexfaceused: number of flex faces currently in use (nflex)
• flexedge: flex edge data (2*nflexedge)
• flexvert: flex vertices (3*nflexvert)
• flexface: flex faces vertices (9*sum(flexfacenum))
• flexnormal: flex face normals (9*sum(flexfacenum))
• flextexcoord: flex face texture coordinates (6*sum(flexfacenum))
• flexvertopt: copy of mjVIS_FLEXVERT mjvOption flag
• flexedgeopt: copy of mjVIS_FLEXEDGE mjvOption flag
• flexfaceopt: copy of mjVIS_FLEXFACE mjvOption flag
• flexskinopt: copy of mjVIS_FLEXSKIN mjvOption flag
• nskin: number of skins
• skinfacenum: number of faces in skin (nskin)
• skinvertadr: address of skin vertices (nskin)
• skinvertnum: number of vertices in skin (nskin)
• skinvert: skin vertex data (3*nskinvert)
• skinnormal: skin normal data (3*nskinvert)
• nlight: number of lights currently in buffer
• lights: buffer for lights (nlight)
• camera: left and right camera
• enabletransform: enable model transformation
• translate: model translation
• rotate: model quaternion rotation
• scale: model scaling
• stereo: stereoscopic rendering (mjtStereo)
• flags: rendering flags (indexed by mjtRndFlag)
• framewidth: frame pixel width; 0: disable framing
• framergb: frame color

mj_Euler(m, d)

Euler integrator, semi-implicit in velocity.

mj_RungeKutta(m, d, N)

Runge-Kutta explicit order-N integrator.

mj_addBufferVFS(vfs, name, buffer, nbuffer)

Add file to VFS from buffer, return 0: success, 1: full, 2: repeated name, -1: failed to load.

mj_addContact(m, d, con)

Add contact to d->contact list; return 0 if success; 1 if buffer full.

mj_addFileVFS(vfs, directory, filename)

Add file to VFS, return 0: success, 1: full, 2: repeated name, -1: failed to load.

mj_addM(m, d, dst, rownnz, rowadr, colind)

Add inertia matrix to destination matrix. Destination can be sparse uncompressed, or dense when all int* are NULL

mj_angmomMat(m, d, mat, body)

Compute subtree angular momentum matrix.

mj_applyFT(m, d, force, torque, point, body, qfrc_target)

Apply Cartesian force and torque (outside xfrc_applied mechanism).

mj_camlight(m, d)

Compute camera and light positions and orientations.

mj_checkAcc(m, d)

Check qacc, reset if any element is too big or nan.

mj_checkPos(m, d)

Check qpos, reset if any element is too big or nan.

mj_checkVel(m, d)

Check qvel, reset if any element is too big or nan.

mj_collision(m, d)

Run collision detection.

mj_comPos(m, d)

Map inertias and motion dofs to global frame centered at CoM.

mj_comVel(m, d)

Compute cvel, cdof_dot.

mj_compareFwdInv(m, d)

Compare forward and inverse dynamics, save results in fwdinv.

mj_constraintUpdate(m, d, jar, cost, flg_coneHessian)

Compute efcstate, efcforce, qfrc_constraint, and (optionally) cone Hessians. If cost is not NULL, set cost = s(jar) where jar = Jacqacc-aref.

mj_contactForce(m, d, id, result)

Extract 6D force:torque given contact id, in the contact frame.

mj_copyData(dest, m, src)

Copy mjData. m is only required to contain the size fields from MJMODEL_INTS.

mj_copyModel(dest, src)

Copy mjModel, allocate new if dest is NULL.

mj_crb(m, d)

Run composite rigid body inertia algorithm (CRB).

mj_defaultLROpt(opt)

Set default options for length range computation.

mj_defaultOption(opt)

Set physics options to default values.

mj_defaultSolRefImp(solref, solimp)

Set solver parameters to default values.

mj_defaultVFS(vfs)

Initialize VFS to empty (no deallocation).

mj_defaultVisual(vis)

Set visual options to default values.

mj_deleteData(d)

Free memory allocation in mjData.

mj_deleteFileVFS(vfs, filename)

Delete file from VFS, return 0: success, -1: not found in VFS.

mj_deleteModel(m)

Free memory allocation in model.

mj_deleteVFS(vfs)

Delete all files from VFS.

mj_differentiatePos(m, qvel, dt, qpos1, qpos2)

Compute velocity by finite-differencing two positions.

mj_energyPos(m, d)

Evaluate position-dependent energy (potential).

mj_energyVel(m, d)

Evaluate velocity-dependent energy (kinetic).

mj_factorM(m, d)

Compute sparse L'DL factorizaton of inertia matrix.

mj_findFileVFS(vfs, filename)

Return file index in VFS, or -1 if not found in VFS.

mj_flex(m, d)

Compute flex-related quantities.

mj_forward(m, d)

Forward dynamics: same as mj_step but do not integrate in time.

mj_forwardSkip(m, d, skipstage, skipsensor)

Forward dynamics with skip; skipstage is mjtStage.

mj_freeLastXML()

Free last XML model if loaded. Called internally at each load.

mj_freeStack(d)

Free the current mjData stack frame. All pointers returned by mjstackAlloc since the last call to mjmarkStack must no longer be used afterwards.

mj_fullM(m, dst, M)

Convert sparse inertia matrix M into full (i.e. dense) matrix.

mj_fwdAcceleration(m, d)

Add up all non-constraint forces, compute qacc_smooth.

mj_fwdActuation(m, d)

Compute actuator force qfrc_actuator.

mj_fwdConstraint(m, d)

Run selected constraint solver.

mj_fwdPosition(m, d)

Run position-dependent computations.

mj_fwdVelocity(m, d)

Run velocity-dependent computations.

mj_geomDistance(m, d, geom1, geom2, distmax, fromto)

Returns smallest signed distance between two geoms and optionally segment from geom1 to geom2.

mj_getPluginConfig(m, plugin_id, attrib)

Return a config attribute value of a plugin instance; NULL: invalid plugin instance ID or attribute name

mj_getState(m, d, state, spec)

Get state.

mj_getTotalmass(m)

Sum all body masses.

mj_id2name(m, type, id)

Get name of object with the specified mjtObj type and id, returns NULL if name not found.

mj_implicit(m, d)

Implicit-in-velocity integrators.

mj_integratePos(m, qpos, qvel, dt)

Integrate position with given velocity.

mj_invConstraint(m, d)

Apply the analytical formula for inverse constraint dynamics.

mj_invPosition(m, d)

Run position-dependent computations in inverse dynamics.

mj_invVelocity(m, d)

Run velocity-dependent computations in inverse dynamics.

mj_inverse(m, d)

Inverse dynamics: qacc must be set before calling.

mj_inverseSkip(m, d, skipstage, skipsensor)

Inverse dynamics with skip; skipstage is mjtStage.

mj_isDual(m)

Determine type of solver (PGS is dual, CG and Newton are primal).

mj_isPyramidal(m)

Determine type of friction cone.

mj_isSparse(m)

Determine type of constraint Jacobian.

mj_island(m, d)

Find constraint islands.

mj_jac(m, d, jacp, jacr, point, body)

Compute 3/6-by-nv end-effector Jacobian of global point attached to given body.

mj_jacBody(m, d, jacp, jacr, body)

Compute body frame end-effector Jacobian.

mj_jacBodyCom(m, d, jacp, jacr, body)

Compute body center-of-mass end-effector Jacobian.

mj_jacGeom(m, d, jacp, jacr, geom)

Compute geom end-effector Jacobian.

mj_jacPointAxis(m, d, jacPoint, jacAxis, point, axis, body)

Compute translation end-effector Jacobian of point, and rotation Jacobian of axis.

mj_jacSite(m, d, jacp, jacr, site)

Compute site end-effector Jacobian.

mj_jacSubtreeCom(m, d, jacp, body)

Compute subtree center-of-mass end-effector Jacobian.

mj_kinematics(m, d)

Run forward kinematics.

mj_loadAllPluginLibraries(directory, callback)

Scan a directory and load all dynamic libraries. Dynamic libraries in the specified directory are assumed to register one or more plugins. Optionally, if a callback is specified, it is called for each dynamic library encountered that registers plugins.

mj_loadModel(filename, vfs)

Load model from binary MJB file. If vfs is not NULL, look up file in vfs before reading from disk.

mj_loadPluginLibrary(path)

Load a dynamic library. The dynamic library is assumed to register one or more plugins.

mj_loadXML(filename, vfs, error, error_sz)

Parse XML file in MJCF or URDF format, compile it, return low-level model. If vfs is not NULL, look up files in vfs before reading from disk. If error is not NULL, it must have size error_sz.

mj_local2Global(d, xpos, xmat, pos, quat, body, sameframe)

Map from body local to global Cartesian coordinates.

mj_makeConstraint(m, d)

Construct constraints.

mj_makeData(m)

Allocate mjData corresponding to given model. If the model buffer is unallocated the initial configuration will not be set.

mj_makeEmptyFileVFS(vfs, filename, filesize)

deprecated: use mj_copyBufferVFS.

mj_markStack(d)

Mark a new frame on the mjData stack.

mj_mulJacTVec(m, d, res, vec)

Multiply dense or sparse constraint Jacobian transpose by vector.

mj_mulJacVec(m, d, res, vec)

Multiply dense or sparse constraint Jacobian by vector.

mj_mulM(m, d, res, vec)

Multiply vector by inertia matrix.

mj_mulM2(m, d, res, vec)

Multiply vector by (inertia matrix)^(1/2).

mj_multiRay(m, d, pnt, vec, geomgroup, flg_static, bodyexclude, geomid, dist, nray, cutoff)

Intersect multiple rays emanating from a single point. Similar semantics to mj_ray, but vec is an array of (nray x 3) directions.

mj_name2id(m, type, name)

Get id of object with the specified mjtObj type and name, returns -1 if id not found.

mj_normalizeQuat(m, qpos)

Normalize all quaternions in qpos-type vector.

mj_objectAcceleration(m, d, objtype, objid, res, flg_local)

Compute object 6D acceleration (rot:lin) in object-centered frame, world/local orientation.

mj_objectVelocity(m, d, objtype, objid, res, flg_local)

Compute object 6D velocity (rot:lin) in object-centered frame, world/local orientation.

mj_passive(m, d)

Compute qfrc_passive from spring-dampers, gravity compensation and fluid forces.

mj_printData(m, d, filename)

Print data to text file.

mj_printFormattedData(m, d, filename, float_format)

Print mjData to text file, specifying format. float_format must be a valid printf-style format string for a single float value

mj_printFormattedModel(m, filename, float_format)

Print mjModel to text file, specifying format. float_format must be a valid printf-style format string for a single float value.

mj_printModel(m, filename)

Print model to text file.

mj_printSchema(filename, buffer, buffer_sz, flg_html, flg_pad)

Print internal XML schema as plain text or HTML, with style-padding or &nbsp;.

mj_projectConstraint(m, d)

Compute inverse constraint inertia efc_AR.

mj_ray(m, d, pnt, vec, geomgroup, flg_static, bodyexclude, geomid)

Intersect ray (pnt+x*vec, x>=0) with visible geoms, except geoms in bodyexclude. Return distance (x) to nearest surface, or -1 if no intersection and output geomid. geomgroup, flg_static are as in mjvOption; geomgroup==NULL skips group exclusion.

mj_rayHfield(m, d, geomid, pnt, vec)

Intersect ray with hfield, return nearest distance or -1 if no intersection.

mj_rayMesh(m, d, geomid, pnt, vec)

Intersect ray with mesh, return nearest distance or -1 if no intersection.

mj_referenceConstraint(m, d)

Compute efcvel, efcaref.

mj_resetCallbacks()

Reset all callbacks to NULL pointers (NULL is the default).

mj_resetData(m, d)

Reset data to defaults.

mj_resetDataDebug(m, d, debug_value)

Reset data to defaults, fill everything else with debug_value.

mj_resetDataKeyframe(m, d, key)

Reset data. If 0 <= key < nkey, set fields from specified keyframe.

mj_rne(m, d, flg_acc, result)

RNE: compute M(qpos)*qacc + C(qpos,qvel); flg_acc=0 removes inertial term.

mj_rnePostConstraint(m, d)

RNE with complete data: compute cacc, cfrcext, cfrcint.

mj_saveLastXML(filename, m, error, error_sz)

Update XML data structures with info from low-level model, save as MJCF. If error is not NULL, it must have size error_sz.

mj_saveModel(m, filename, buffer, buffer_sz)

Save model to binary MJB file or memory buffer; buffer has precedence when given.

mj_sensorAcc(m, d)

Evaluate acceleration and force-dependent sensors.

mj_sensorPos(m, d)

Evaluate position-dependent sensors.

mj_sensorVel(m, d)

Evaluate velocity-dependent sensors.

mj_setConst(m, d)

Set constant fields of mjModel, corresponding to qpos0 configuration.

mj_setLengthRange(m, d, index, opt, error, error_sz)

Set actuator_lengthrange for specified actuator; return 1 if ok, 0 if error.

mj_setState(m, d, state, spec)

Set state.

mj_setTotalmass(m, newmass)

Scale body masses and inertias to achieve specified total mass.

mj_sizeModel(m)

Return size of buffer needed to hold model.

mj_solveM(m, d, x, y, n)

Solve linear system M * x = y using factorization: x = inv(L'DL)*y

mj_solveM2(m, d, x, y, n)

Half of linear solve: x = sqrt(inv(D))inv(L')y

mj_stackAllocByte(d, bytes, alignment)

Allocate a number of bytes on mjData stack at a specific alignment. Call mju_error on stack overflow.

mj_stackAllocInt(d, size)

Allocate array of ints on mjData stack. Call mju_error on stack overflow.

mj_stackAllocNum(d, size)

Allocate array of mjtNums on mjData stack. Call mju_error on stack overflow.

mj_stateSize(m, spec)

Return size of state specification.

mj_step(m, d)

Advance simulation, use control callback to obtain external force and control.

mj_step1(m, d)

Advance simulation in two steps: before external force and control is set by user.

mj_step2(m, d)

Advance simulation in two steps: after external force and control is set by user.

mj_subtreeVel(m, d)

Sub-tree linear velocity and angular momentum: compute subtreelinvel, subtreeangmom.

mj_tendon(m, d)

Compute tendon lengths, velocities and moment arms.

mj_transmission(m, d)

Compute actuator transmission lengths and moments.

mj_version()

Return version number: 1.0.2 is encoded as 102.

mj_versionString()

Return the current version of MuJoCo as a null-terminated string.

mj_warning(d, warning, info)

High-level warning function: count warnings in mjData, print only the first.

mjd_inverseFD(m, d, eps, flg_actuation, DfDq, DfDv, DfDa, DsDq, DsDv, DsDa, DmDq)

Finite differenced Jacobians of (force, sensors) = mjinverse(state, acceleration) All outputs are optional. Output dimensions (transposed w.r.t Control Theory convention): DfDq: (nv x nv) DfDv: (nv x nv) DfDa: (nv x nv) DsDq: (nv x nsensordata) DsDv: (nv x nsensordata) DsDa: (nv x nsensordata) DmDq: (nv x nM) single-letter shortcuts: inputs: q=qpos, v=qvel, a=qacc outputs: f=qfrcinverse, s=sensordata, m=qM notes: optionally computes mass matrix Jacobian DmDq flgactuation specifies whether to subtract qfrcactuator from qfrc_inverse

mjd_quatIntegrate(vel, scale, Dquat, Dvel, Dscale)

Derivatives of mju_quatIntegrate.

mjd_subQuat(qa, qb, Da, Db)

Derivatives of mju_subQuat.

mjd_transitionFD(m, d, eps, flg_centered, A, B, C, D)

Finite differenced transition matrices (control theory notation) d(x_next) = Adx + Bdu d(sensor) = Cdx + Ddu required output matrix dimensions: A: (2nv+na x 2nv+na) B: (2nv+na x nu) D: (nsensordata x 2nv+na) C: (nsensordata x nu)

mjp_defaultPlugin(plugin)

Set default plugin definition.

mjp_defaultResourceProvider(provider)

Set default resource provider definition.

mjp_getPlugin(name, slot)

Look up a plugin by name. If slot is not NULL, also write its registered slot number into it.

mjp_getPluginAtSlot(slot)

Look up a plugin by the registered slot number that was returned by mjp_registerPlugin.

mjp_getResourceProvider(resource_name)

Return the resource provider with the prefix that matches against the resource name. If no match, return NULL.

mjp_getResourceProviderAtSlot(slot)

Look up a resource provider by slot number returned by mjp_registerResourceProvider. If invalid slot number, return NULL.

mjp_pluginCount()

Return the number of globally registered plugins.

mjp_registerPlugin(plugin)

Globally register a plugin. This function is thread-safe. If an identical mjpPlugin is already registered, this function does nothing. If a non-identical mjpPlugin with the same name is already registered, an mju_error is raised. Two mjpPlugins are considered identical if all member function pointers and numbers are equal, and the name and attribute strings are all identical, however the char pointers to the strings need not be the same.

mjp_registerResourceProvider(provider)

Globally register a resource provider in a thread-safe manner. The provider must have a prefix that is not a sub-prefix or super-prefix of any current registered providers. This function returns a slot number > 0 on success.

mjp_resourceProviderCount()

Return the number of globally registered resource providers.

mjr_addAux(index, width, height, samples, con)

Add Aux buffer with given index to context; free previous Aux buffer.

mjr_blitAux(index, src, left, bottom, con)

Blit from Aux buffer to con->currentBuffer.

mjr_blitBuffer(src, dst, flg_color, flg_depth, con)

Blit from src viewpoint in current framebuffer to dst viewport in other framebuffer. If src, dst have different size and flgdepth==0, color is interpolated with GLLINEAR.

mjr_changeFont(fontscale, con)

Change font of existing context.

mjr_defaultContext(con)

Set default mjrContext.

mjr_drawPixels(rgb, depth, viewport, con)

Draw pixels from client buffer to current OpenGL framebuffer. Viewport is in OpenGL framebuffer; client buffer starts at (0,0).

mjr_figure(viewport, fig, con)

Draw 2D figure.

mjr_findRect(x, y, nrect, rect)

Find first rectangle containing mouse, -1: not found.

mjr_finish()

Call glFinish.

mjr_freeContext(con)

Free resources in custom OpenGL context, set to default.

mjr_getError()

Call glGetError and return result.

mjr_label(viewport, font, txt, r, g, b, a, rt, gt, bt, con)

Draw rectangle with centered text.

mjr_makeContext(m, con, fontscale)

Allocate resources in custom OpenGL context; fontscale is mjtFontScale.

mjr_maxViewport(con)

Get maximum viewport for active buffer.

mjr_overlay(font, gridpos, viewport, overlay, overlay2, con)

Draw text overlay; font is mjtFont; gridpos is mjtGridPos.

mjr_readPixels(rgb, depth, viewport, con)

Read pixels from current OpenGL framebuffer to client buffer. Viewport is in OpenGL framebuffer; client buffer starts at (0,0).

mjr_rectangle(viewport, r, g, b, a)

Draw rectangle.

mjr_render(viewport, scn, con)

Render 3D scene.

mjr_resizeOffscreen(width, height, con)

Resize offscreen buffers.

mjr_restoreBuffer(con)

Make con->currentBuffer current again.

mjr_setAux(index, con)

Set Aux buffer for custom OpenGL rendering (call restoreBuffer when done).

mjr_setBuffer(framebuffer, con)

Set OpenGL framebuffer for rendering: mjFBWINDOW or mjFBOFFSCREEN. If only one buffer is available, set that buffer and ignore framebuffer argument.

mjr_text(font, txt, con, x, y, r, g, b)

Draw text at (x,y) in relative coordinates; font is mjtFont.

mjr_uploadHField(m, con, hfieldid)

Upload height field to GPU, overwriting previous upload if any.

mjr_uploadMesh(m, con, meshid)

Upload mesh to GPU, overwriting previous upload if any.

mjr_uploadTexture(m, con, texid)

Upload texture to GPU, overwriting previous upload if any.

mju_Halton(index, base)

Generate Halton sequence.

mju_L1(vec, n)

Return L1 norm: sum(abs(vec)).

mju_add(res, vec1, vec2, n)

Set res = vec1 + vec2.

mju_add3(res, vec1, vec2)

Set res = vec1 + vec2.

mju_addScl(res, vec1, vec2, scl, n)

Set res = vec1 + vec2*scl.

mju_addScl3(res, vec1, vec2, scl)

Set res = vec1 + vec2*scl.

mju_addTo(res, vec, n)

Set res = res + vec.

mju_addTo3(res, vec)

Set res = res + vec.

mju_addToScl(res, vec, scl, n)

Set res = res + vec*scl.

mju_addToScl3(res, vec, scl)

Set res = res + vec*scl.

mju_axisAngle2Quat(res, axis, angle)

Convert axisAngle to quaternion.

mju_band2Dense(res, mat, ntotal, nband, ndense, flg_sym)

Convert banded matrix to dense matrix, fill upper triangle if flg_sym>0.

mju_bandDiag(i, ntotal, nband, ndense)

Address of diagonal element i in band-dense matrix representation.

mju_bandMulMatVec(res, mat, vec, ntotal, nband, ndense, nvec, flg_sym)

Multiply band-diagonal matrix with nvec vectors, include upper triangle if flg_sym>0.

mju_bindThreadPool(d, thread_pool)

Adds a thread pool to mjData and configures it for multi-threaded use.

mju_boxQP(res, R, index, H, g, n, lower, upper)

minimize 0.5x'Hx + x'g s.t. lower <= x <= upper, return rank or -1 if failed inputs: n - problem dimension H - SPD matrix nn g - bias vector n lower - lower bounds n upper - upper bounds n res - solution warmstart n return value: nfree <= n - rank of unconstrained subspace, -1 if failure outputs (required): res - solution n R - subspace Cholesky factor nfreenfree allocated: n(n+7) outputs (optional): index - set of free dimensions nfree allocated: n notes: the initial value of res is used to warmstart the solver R must have allocatd size n(n+7), but only nfree*nfree values are used in output index (if given) must have allocated size n, but only nfree values are used in output only the lower triangles of H and R and are read from and written to, respectively the convenience function mju_boxQPmalloc allocates the required data structures

mju_boxQPmalloc(res, R, index, H, g, n, lower, upper)

allocate heap memory for box-constrained Quadratic Program as in mjuboxQP, index, lower, and upper are optional free all pointers with mjufree()

mju_cholFactor(mat, n, mindiag)

Cholesky decomposition: mat = L*L'; return rank, decomposition performed in-place into mat.

mju_cholFactorBand(mat, ntotal, nband, ndense, diagadd, diagmul)

Band-dense Cholesky decomposition. Returns minimum value in the factorized diagonal, or 0 if rank-deficient. mat has (ntotal-ndense) x nband + ndense x ntotal elements. The first (ntotal-ndense) x nband store the band part, left of diagonal, inclusive. The second ndense x ntotal store the band part as entire dense rows. Add diagadd+diagmul*mat_ii to diagonal before factorization.

mju_cholSolve(res, mat, vec, n)

Solve (mat*mat') * res = vec, where mat is a Cholesky factor.

mju_cholSolveBand(res, mat, vec, ntotal, nband, ndense)

Solve (matmat')res = vec where mat is a band-dense Cholesky factor.

mju_cholUpdate(mat, x, n, flg_plus)

Cholesky rank-one update: LL' +/- xx'; return rank.

mju_clearHandlers()

Clear user error and memory handlers.

mju_clip(x, min, max)

Clip x to the range [min, max].

mju_copy(res, vec, n)

Set res = vec.

mju_copy3(res, data)

Set res = vec.

mju_copy4(res, data)

Set res = vec.

mju_cross(res, a, b)

Compute cross-product: res = cross(a, b).

mju_d2n(res, vec, n)

Convert from double to mjtNum.

mju_decodePyramid(force, pyramid, mu, dim)

Convert pyramid representation to contact force.

mju_defaultTask(task)

Initialize an mjTask.

mju_dense2Band(res, mat, ntotal, nband, ndense)

Convert dense matrix to banded matrix.

mju_derivQuat(res, quat, vel)

Compute time-derivative of quaternion, given 3D rotational velocity.

mju_dist3(pos1, pos2)

Return Cartesian distance between 3D vectors pos1 and pos2.

mju_dot(vec1, vec2, n)

Return dot-product of vec1 and vec2.

mju_dot3(vec1, vec2)

Return dot-product of vec1 and vec2.

mju_eig3(eigval, eigvec, quat, mat)

Eigenvalue decomposition of symmetric 3x3 matrix, mat = eigvec * diag(eigval) * eigvec'.

mju_encodePyramid(pyramid, force, mu, dim)

Convert contact force to pyramid representation.

mju_error_i(msg, i)

Deprecated: use mju_error.

mju_error_s(msg, text)

Deprecated: use mju_error.

mju_euler2Quat(quat, euler, seq)

Convert sequence of Euler angles (radians) to quaternion. seq[0,1,2] must be in 'xyzXYZ', lower/upper-case mean intrinsic/extrinsic rotations.

mju_eye(mat, n)

Set mat to the identity matrix.

mju_f2n(res, vec, n)

Convert from float to mjtNum.

mju_fill(res, val, n)

Set res = val.

mju_free(ptr)

Free memory, using free() by default.

mju_insertionSort(list, n)

Insertion sort, resulting list is in increasing order.

mju_insertionSortInt(list, n)

Integer insertion sort, resulting list is in increasing order.

mju_isBad(x)

Return 1 if nan or abs(x)>mjMAXVAL, 0 otherwise. Used by check functions.

mju_isZero(vec, n)

Return 1 if all elements are 0.

mju_malloc(size)

Allocate memory; byte-align on 64; pad size to multiple of 64.

mju_mat2Quat(quat, mat)

Convert 3D rotation matrix to quaternion.

mju_max(a, b)

Return max(a,b) with single evaluation of a and b.

mju_min(a, b)

Return min(a,b) with single evaluation of a and b.

mju_mulMatMat(res, mat1, mat2, r1, c1, c2)

Multiply matrices: res = mat1 * mat2.

mju_mulMatMatT(res, mat1, mat2, r1, c1, r2)

Multiply matrices, second argument transposed: res = mat1 * mat2'.

mju_mulMatTMat(res, mat1, mat2, r1, c1, c2)

Multiply matrices, first argument transposed: res = mat1' * mat2.

mju_mulMatTVec(res, mat, vec, nr, nc)

Multiply transposed matrix and vector: res = mat' * vec.

mju_mulMatVec(res, mat, vec, nr, nc)

Multiply matrix and vector: res = mat * vec.

mju_mulPose(posres, quatres, pos1, quat1, pos2, quat2)

Multiply two poses.

mju_mulQuat(res, quat1, quat2)

Multiply quaternions.

mju_mulQuatAxis(res, quat, axis)

Multiply quaternion and axis.

mju_mulVecMatVec(vec1, mat, vec2, n)

Multiply square matrix with vectors on both sides: returns vec1' * mat * vec2.

mju_muscleBias(len, lengthrange, acc0, prm)

Muscle passive force, prm = (range[2], force, scale, lmin, lmax, vmax, fpmax, fvmax).

mju_muscleDynamics(ctrl, act, prm)

Muscle activation dynamics, prm = (tauact, taudeact, smoothing_width).

mju_muscleGain(len, vel, lengthrange, acc0, prm)

Muscle active force, prm = (range[2], force, scale, lmin, lmax, vmax, fpmax, fvmax).

mju_n2d(res, vec, n)

Convert from mjtNum to double.

mju_n2f(res, vec, n)

Convert from mjtNum to float.

mju_negPose(posres, quatres, pos, quat)

Conjugate pose, corresponding to the opposite spatial transformation.

mju_negQuat(res, quat)

Conjugate quaternion, corresponding to opposite rotation.

mju_norm(res, n)

Return vector length (without normalizing vector).

mju_norm3(vec)

Return vector length (without normalizing the vector).

mju_normalize(res, n)

Normalize vector, return length before normalization.

mju_normalize3(vec)

Normalize vector, return length before normalization.

mju_normalize4(vec)

Normalize vector, return length before normalization.

mju_printMat(mat, nr, nc)

Print matrix to screen.

mju_printMatSparse(mat, nr, rownnz, rowadr, colind)

Print sparse matrix to screen.

mju_quat2Mat(res, quat)

Convert quaternion to 3D rotation matrix.

mju_quat2Vel(res, quat, dt)

Convert quaternion (corresponding to orientation difference) to 3D velocity.

mju_quatIntegrate(quat, vel, scale)

Integrate quaternion given 3D angular velocity.

mju_quatZ2Vec(quat, vec)

Construct quaternion performing rotation from z-axis to given vector.

mju_rayFlex(m, d, flex_layer, flg_vert, flg_edge, flg_face, flg_skin, flexid, pnt, vec, vertid)

Intersect ray with flex, return nearest distance or -1 if no intersection, and also output nearest vertex id.

mju_rayGeom(pos, mat, size, pnt, vec, geomtype)

Intersect ray with pure geom, return nearest distance or -1 if no intersection.

mju_raySkin(nface, nvert, face, vert, pnt, vec, vertid)

Intersect ray with skin, return nearest distance or -1 if no intersection, and also output nearest vertex id.

mju_rotVecMat(res, vec, mat)

Multiply vector by 3D rotation matrix: res = mat * vec.

mju_rotVecMatT(res, vec, mat)

Multiply vector by transposed 3D rotation matrix: res = mat' * vec.

mju_rotVecQuat(res, vec, quat)

Rotate vector by quaternion.

mju_round(x)

Round x to nearest integer.

mju_scl(res, vec, scl, n)

Set res = vec*scl.

mju_scl3(res, vec, scl)

Set res = vec*scl.

mju_sigmoid(x)

Sigmoid function over 0<=x<=1 using quintic polynomial.

mju_sign(x)

Return sign of x: +1, -1 or 0.

mju_springDamper(pos0, vel0, Kp, Kv, dt)

Integrate spring-damper analytically, return pos(dt).

mju_sqrMatTD(res, mat, diag, nr, nc)

Set res = mat' * diag * mat if diag is not NULL, and res = mat' * mat otherwise.

mju_standardNormal(num2)

Standard normal random number generator (optional second number).

mju_str2Type(str)

Convert type name to type id (mjtObj).

mju_strncpy(dst, src, n)

Call strncpy, then set dst[n-1] = 0.

mju_sub(res, vec1, vec2, n)

Set res = vec1 - vec2.

mju_sub3(res, vec1, vec2)

Set res = vec1 - vec2.

mju_subFrom(res, vec, n)

Set res = res - vec.

mju_subFrom3(res, vec)

Set res = res - vec.

mju_subQuat(res, qa, qb)

Subtract quaternions, express as 3D velocity: qb*quat(res) = qa.

mju_sum(vec, n)

Return sum(vec).

mju_symmetrize(res, mat, n)

Symmetrize square matrix res = (mat + mat')/2.

mju_taskJoin(task)

Wait for a task to complete.

mju_threadPoolCreate(number_of_threads)

Create a thread pool with the specified number of threads running.

mju_threadPoolDestroy(thread_pool)

Destroy a thread pool.

mju_threadPoolEnqueue(thread_pool, task)

Enqueue a task in a thread pool.

mju_transformSpatial(res, vec, flg_force, newpos, oldpos, rotnew2old)

Coordinate transform of 6D motion or force vector in rotation:translation format. rotnew2old is 3-by-3, NULL means no rotation; flg_force specifies force or motion type.

mju_transpose(res, mat, nr, nc)

Transpose matrix: res = mat'.

mju_trnVecPose(res, pos, quat, vec)

Transform vector by pose.

mju_type2Str(type)

Convert type id (mjtObj) to type name.

mju_unit4(res)

Set res = (1,0,0,0).

mju_warningText(warning, info)

Construct a warning message given the warning type and info.

mju_warning_i(msg, i)

Deprecated: use mju_warning.

mju_warning_s(msg, text)

Deprecated: use mju_warning.

mju_writeLog(type, msg)

Write [datetime, type: message] to MUJOCO_LOG.TXT.

mju_writeNumBytes(nbytes)

Return human readable number of bytes using standard letter suffix.

mju_zero(res, n)

Set res = 0.

mju_zero3(res)

Set res = 0.

mju_zero4(res)

Set res = 0.

mjui_add(ui, def)

Add definitions to UI.

mjui_addToSection(ui, sect, def)

Add definitions to UI section.

mjui_event(ui, state, con)

Handle UI event, return pointer to changed item, NULL if no change.

mjui_render(ui, state, con)

Copy UI image to current buffer.

mjui_resize(ui, con)

Compute UI sizes.

mjui_themeColor(ind)

Get builtin UI theme color (ind: 0-3).

mjui_themeSpacing(ind)

Get builtin UI theme spacing (ind: 0-1).

mjui_update(section, item, ui, state, con)

Update specific section/item; -1: update all.

mjv_addGeoms(m, d, opt, pert, catmask, scn)

Add geoms from selected categories.

mjv_alignToCamera(res, vec, forward)

Rotate 3D vec in horizontal plane by angle between (0,1) and (forwardx,forwardy).

mjv_applyPerturbForce(m, d, pert)

Set perturb force,torque in d->xfrc_applied, if selected body is dynamic.

mjv_applyPerturbPose(m, d, pert, flg_paused)

Set perturb pos,quat in d->mocap when selected body is mocap, and in d->qpos otherwise. Write d->qpos only if flg_paused and subtree root for selected body has free joint.

mjv_averageCamera(cam1, cam2)

Return the average of two OpenGL cameras.

mjv_cameraInModel(headpos, forward, up, scn)

Get camera info in model space; average left and right OpenGL cameras.

mjv_cameraInRoom(headpos, forward, up, scn)

Get camera info in room space; average left and right OpenGL cameras.

mjv_connector(geom, type, width, from, to)

Set (type, size, pos, mat) for connector-type geom between given points. Assume that mjvinitGeom was already called to set all other properties. Width of mjGEOMLINE is denominated in pixels.

mjv_defaultCamera(cam)

Set default camera.

mjv_defaultFigure(fig)

Set default figure.

mjv_defaultFreeCamera(m, cam)

Set default free camera.

mjv_defaultOption(opt)

Set default visualization options.

mjv_defaultPerturb(pert)

Set default perturbation.

mjv_defaultScene(scn)

Set default abstract scene.

mjv_defaultSceneState(scnstate)

Set default scene state.

mjv_freeScene(scn)

Free abstract scene.

mjv_freeSceneState(scnstate)

Free scene state.

mjv_frustumHeight(scn)

Get frustum height at unit distance from camera; average left and right OpenGL cameras.

mjv_initGeom(geom, type, size, pos, mat, rgba)

Initialize given geom fields when not NULL, set the rest to their default values.

mjv_initPerturb(m, d, scn, pert)

Copy perturb pos,quat from selected body; set scale for perturbation.

mjv_makeConnector(geom, type, width, a0, a1, a2, b0, b1, b2)

Set (type, size, pos, mat) for connector-type geom between given points. Assume that mjvinitGeom was already called to set all other properties. Width of mjGEOMLINE is denominated in pixels. Deprecated: use mjv_connector.

mjv_makeLights(m, d, scn)

Make list of lights.

mjv_makeScene(m, scn, maxgeom)

Allocate resources in abstract scene.

mjv_makeSceneState(m, d, scnstate, maxgeom)

Allocate resources and initialize a scene state object.

mjv_model2room(roompos, roomquat, modelpos, modelquat, scn)

Transform pose from model to room space.

mjv_moveCamera(m, action, reldx, reldy, scn, cam)

Move camera with mouse; action is mjtMouse.

mjv_moveCameraFromState(scnstate, action, reldx, reldy, scn, cam)

Move camera with mouse given a scene state; action is mjtMouse.

mjv_moveModel(m, action, reldx, reldy, roomup, scn)

Move model with mouse; action is mjtMouse.

mjv_movePerturb(m, d, action, reldx, reldy, scn, pert)

Move perturb object with mouse; action is mjtMouse.

mjv_movePerturbFromState(scnstate, action, reldx, reldy, scn, pert)

Move perturb object with mouse given a scene state; action is mjtMouse.

mjv_room2model(modelpos, modelquat, roompos, roomquat, scn)

Transform pose from room to model space.

mjv_select(m, d, vopt, aspectratio, relx, rely, scn, selpnt, geomid, flexid, skinid)

Select geom, flex or skin with mouse, return bodyid; -1: none selected.

mjv_updateCamera(m, d, cam, scn)

Update camera.

mjv_updateScene(m, d, opt, pert, cam, catmask, scn)

Update entire scene given model state.

mjv_updateSceneFromState(scnstate, opt, pert, cam, catmask, scn)

Update entire scene from a scene state, return the number of new mjWARN_VGEOMFULL warnings.

mjv_updateSceneState(m, d, opt, scnstate)

Update a scene state from model and data.

mjv_updateSkin(m, d, scn)

Update skins.