The surface parameters Bounciness coefficient of restitution, from [0...1], where 0=no bounciness. Bounce capture velocity, below which effective coefficient of restitution is 0. Parameters for torsional friction Torsional friction coefficient, unitless maximum ratio of tangential stress to normal stress. If this flag is true, torsional friction is calculated using the "patch_radius" parameter. If this flag is set to false, "surface_radius" (R) and contact depth (d) are used to compute the patch radius as sqrt(R*d). Radius of contact patch surface. Surface radius on the point of contact. Torsional friction parameters for ODE Force dependent slip for torsional friction, equivalent to inverse of viscous damping coefficient with units of rad/s/(Nm). A slip value of 0 is infinitely viscous. ODE friction parameters Coefficient of friction in first friction pyramid direction, the unitless maximum ratio of force in first friction pyramid direction to normal force. Coefficient of friction in second friction pyramid direction, the unitless maximum ratio of force in second friction pyramid direction to normal force. Unit vector specifying first friction pyramid direction in collision-fixed reference frame. If the friction pyramid model is in use, and this value is set to a unit vector for one of the colliding surfaces, the ODE Collide callback function will align the friction pyramid directions with a reference frame fixed to that collision surface. If both surfaces have this value set to a vector of zeros, the friction pyramid directions will be aligned with the world frame. If this value is set for both surfaces, the behavior is undefined. Force dependent slip in first friction pyramid direction, equivalent to inverse of viscous damping coefficient with units of m/s/N. A slip value of 0 is infinitely viscous. Force dependent slip in second friction pyramid direction, equivalent to inverse of viscous damping coefficient with units of m/s/N. A slip value of 0 is infinitely viscous. Coefficient of friction in first friction pyramid direction, the unitless maximum ratio of force in first friction pyramid direction to normal force. Coefficient of friction in second friction pyramid direction, the unitless maximum ratio of force in second friction pyramid direction to normal force. Unit vector specifying first friction pyramid direction in collision-fixed reference frame. If the friction pyramid model is in use, and this value is set to a unit vector for one of the colliding surfaces, the friction pyramid directions will be aligned with a reference frame fixed to that collision surface. If both surfaces have this value set to a vector of zeros, the friction pyramid directions will be aligned with the world frame. If this value is set for both surfaces, the behavior is undefined. Coefficient of rolling friction Flag to disable contact force generation, while still allowing collision checks and contact visualization to occur. Bitmask for collision filtering when collide_without_contact is on Bitmask for collision filtering. This will override collide_without_contact Poisson's ratio is the unitless ratio between transverse and axial strain. This value must lie between (-1, 0.5). Defaults to 0.3 for typical steel. Note typical silicone elastomers have Poisson's ratio near 0.49 ~ 0.50. For reference, approximate values for Material:(Young's Modulus, Poisson's Ratio) for some of the typical materials are: Plastic: (1e8 ~ 3e9 Pa, 0.35 ~ 0.41), Wood: (4e9 ~ 1e10 Pa, 0.22 ~ 0.50), Aluminum: (7e10 Pa, 0.32 ~ 0.35), Steel: (2e11 Pa, 0.26 ~ 0.31). Young's Modulus in SI derived unit Pascal. Defaults to -1. If value is less or equal to zero, contact using elastic modulus (with Poisson's Ratio) is disabled. For reference, approximate values for Material:(Young's Modulus, Poisson's Ratio) for some of the typical materials are: Plastic: (1e8 ~ 3e9 Pa, 0.35 ~ 0.41), Wood: (4e9 ~ 1e10 Pa, 0.22 ~ 0.50), Aluminum: (7e10 Pa, 0.32 ~ 0.35), Steel: (2e11 Pa, 0.26 ~ 0.31). ODE contact parameters Soft constraint force mixing. Soft error reduction parameter dynamically "stiffness"-equivalent coefficient for contact joints dynamically "damping"-equivalent coefficient for contact joints maximum contact correction velocity truncation term. minimum allowable depth before contact correction impulse is applied Bullet contact parameters Soft constraint force mixing. Soft error reduction parameter dynamically "stiffness"-equivalent coefficient for contact joints dynamically "damping"-equivalent coefficient for contact joints Similar to ODE's max_vel implementation. See http://bulletphysics.org/mediawiki-1.5.8/index.php/BtContactSolverInfo#Split_Impulse for more information. Similar to ODE's max_vel implementation. See http://bulletphysics.org/mediawiki-1.5.8/index.php/BtContactSolverInfo#Split_Impulse for more information. soft contact pamameters based on paper: http://www.cc.gatech.edu/graphics/projects/Sumit/homepage/papers/sigasia11/jain_softcontacts_siga11.pdf This is variable k_v in the soft contacts paper. Its unit is N/m. This is variable k_e in the soft contacts paper. Its unit is N/m. Viscous damping of point velocity in body frame. Its unit is N/m/s. Fraction of mass to be distributed among deformable nodes.