1<element name="surface" required="0"> 2 <description>The surface parameters</description> 3 <element name="bounce" required="0"> 4 <description></description> 5 <element name="restitution_coefficient" type="double" default="0" min="0.0" max="1.0" required="0"> 6 <description>Bounciness coefficient of restitution, from [0...1], where 0=no bounciness.</description> 7 </element> 8 <element name="threshold" type="double" default="100000" required="0"> 9 <description>Bounce capture velocity, below which effective coefficient of restitution is 0.</description> 10 </element> 11 </element> <!-- End Bounce --> 12 13 <element name="friction" required="0"> 14 <description></description> 15 16 <element name="torsional" required="0"> 17 <description>Parameters for torsional friction</description> 18 <element name="coefficient" type="double" default="1.0" min="0.0" required="0"> 19 <description>Torsional friction coefficient in the range of [0..1].</description> 20 </element> 21 <element name="use_patch_radius" type="bool" default="1" required="0"> 22 <description> 23 If this flag is true, 24 torsional friction is calculated using the "patch_radius" parameter. 25 If this flag is set to false, 26 "surface_radius" (R) and contact depth (d) 27 are used to compute the patch radius as sqrt(R*d). 28 </description> 29 </element> 30 <element name="patch_radius" type="double" default="0" min="0.0" required="0"> 31 <description>Radius of contact patch surface.</description> 32 </element> 33 <element name="surface_radius" type="double" default="0.0" min="0.0" required="0"> 34 <description>Surface radius on the point of contact.</description> 35 </element> 36 <element name="ode" required="0"> 37 <description>Torsional friction parameters for ODE</description> 38 <element name="slip" type="double" default="0.0" required="0"> 39 <description>Force dependent slip for torsional friction, between the range of [0..1].</description> 40 </element> 41 </element> <!-- End ODE --> 42 </element> <!-- End torsional --> 43 44 <element name="ode" required="0"> 45 <description>ODE friction parameters</description> 46 <element name="mu" type="double" default="1" min="0.0" required="0"> 47 <description>Coefficient of friction in the range of [0..1].</description> 48 </element> 49 <element name="mu2" type="double" default="1" min="0.0" required="0"> 50 <description>Second coefficient of friction in the range of [0..1]</description> 51 </element> 52 <element name="fdir1" type="vector3" default="0 0 0" required="0"> 53 <description>3-tuple specifying direction of mu1 in the collision local reference frame.</description> 54 </element> 55 <element name="slip1" type="double" default="0.0" required="0"> 56 <description>Force dependent slip direction 1 in collision local frame, between the range of [0..1].</description> 57 </element> 58 <element name="slip2" type="double" default="0.0" required="0"> 59 <description>Force dependent slip direction 2 in collision local frame, between the range of [0..1].</description> 60 </element> 61 </element> <!-- End ODE --> 62 <element name="bullet" required="0"> 63 <element name="friction" type="double" default="1" min="0.0" required="0"> 64 <description>Coefficient of friction in the range of [0..1].</description> 65 </element> 66 <element name="friction2" type="double" default="1" min="0.0" required="0"> 67 <description>Coefficient of friction in the range of [0..1].</description> 68 </element> 69 <element name="fdir1" type="vector3" default="0 0 0" required="0"> 70 <description>3-tuple specifying direction of mu1 in the collision local reference frame.</description> 71 </element> 72 <element name="rolling_friction" type="double" default="1" required="0"> 73 <description> coefficient of friction in the range of [0..1]</description> 74 </element> 75 </element> <!-- End Bullet --> 76 </element> <!-- End Friction --> 77 78 <element name="contact" required="0"> 79 <description></description> 80 <element name="collide_without_contact" type="bool" default="0" required="0"> 81 <description>Flag to disable contact force generation, while still allowing collision checks and contact visualization to occur.</description> 82 </element> 83 <element name="collide_without_contact_bitmask" type="unsigned int" default="1" required="0"> 84 <description>Bitmask for collision filtering when collide_without_contact is on </description> 85 </element> 86 87 <element name="collide_bitmask" type="unsigned int" default="65535" required="0"> 88 <description>Bitmask for collision filtering. This will override collide_without_contact</description> 89 </element> 90 91 <element name="poissons_ratio" type="double" default="0.3" required="0"> 92 <description> 93 Poisson's ratio is the ratio between transverse and axial strain. 94 This value must lie between (-1, 0.5). Defaults to 0.3 for typical steel. 95 Note typical silicone elastomers have Poisson's ratio near 0.49 ~ 0.50. 96 97 For reference, approximate values for Material:(Young's Modulus, Poisson's Ratio) 98 for some of the typical materials are: 99 Plastic: (1e8 ~ 3e9 Pa, 0.35 ~ 0.41), 100 Wood: (4e9 ~ 1e10 Pa, 0.22 ~ 0.50), 101 Aluminum: (7e10 Pa, 0.32 ~ 0.35), 102 Steel: (2e11 Pa, 0.26 ~ 0.31). 103 </description> 104 </element> 105 <element name="elastic_modulus" type="double" default="-1" required="0"> 106 <description> 107 Young's Modulus in SI derived unit Pascal. 108 Defaults to -1. If value is less or equal to zero, 109 contact using elastic modulus (with Poisson's Ratio) is disabled. 110 111 For reference, approximate values for Material:(Young's Modulus, Poisson's Ratio) 112 for some of the typical materials are: 113 Plastic: (1e8 ~ 3e9 Pa, 0.35 ~ 0.41), 114 Wood: (4e9 ~ 1e10 Pa, 0.22 ~ 0.50), 115 Aluminum: (7e10 Pa, 0.32 ~ 0.35), 116 Steel: (2e11 Pa, 0.26 ~ 0.31). 117 </description> 118 </element> 119 120 <element name="ode" required="0"> 121 <description>ODE contact parameters</description> 122 <element name="soft_cfm" type="double" default="0" required="0"> 123 <description>Soft constraint force mixing.</description> 124 </element> 125 <element name="soft_erp" type="double" default="0.2" required="0"> 126 <description>Soft error reduction parameter</description> 127 </element> 128 <element name="kp" type="double" default="1000000000000.0" required="0"> 129 <description>dynamically "stiffness"-equivalent coefficient for contact joints</description> 130 </element> 131 <element name="kd" type="double" default="1.0" required="0"> 132 <description>dynamically "damping"-equivalent coefficient for contact joints</description> 133 </element> 134 <element name="max_vel" type="double" default="0.01" required="0"> 135 <description>maximum contact correction velocity truncation term.</description> 136 </element> 137 <element name="min_depth" type="double" default="0" required="0"> 138 <description>minimum allowable depth before contact correction impulse is applied</description> 139 </element> 140 </element> <!-- End ODE --> 141 <element name="bullet" required="0"> 142 <description>Bullet contact parameters</description> 143 <element name="soft_cfm" type="double" default="0" required="0"> 144 <description>Soft constraint force mixing.</description> 145 </element> 146 <element name="soft_erp" type="double" default="0.2" required="0"> 147 <description>Soft error reduction parameter</description> 148 </element> 149 <element name="kp" type="double" default="1000000000000.0" required="0"> 150 <description>dynamically "stiffness"-equivalent coefficient for contact joints</description> 151 </element> 152 <element name="kd" type="double" default="1.0" required="0"> 153 <description>dynamically "damping"-equivalent coefficient for contact joints</description> 154 </element> 155 <element name="split_impulse" type="bool" default="1" required="1"> 156 <description>Similar to ODE's max_vel implementation. See http://bulletphysics.org/mediawiki-1.5.8/index.php/BtContactSolverInfo#Split_Impulse for more information.</description> 157 </element> 158 <element name="split_impulse_penetration_threshold" type="double" default="-0.01" required="1"> 159 <description>Similar to ODE's max_vel implementation. See http://bulletphysics.org/mediawiki-1.5.8/index.php/BtContactSolverInfo#Split_Impulse for more information.</description> 160 </element> 161 </element> <!-- End Bullet --> 162 </element> <!-- End Contact --> 163 164 <!-- for deformable bodies --> 165 <element name="soft_contact" required="0"> 166 <element name="dart" required="0"> 167 <description>soft contact pamameters based on paper: 168 http://www.cc.gatech.edu/graphics/projects/Sumit/homepage/papers/sigasia11/jain_softcontacts_siga11.pdf 169 </description> 170 <element name="bone_attachment" type="double" default="100.0" required="1"> 171 <description>This is variable k_v in the soft contacts paper. Its unit is N/m.</description> 172 </element> 173 <element name="stiffness" type="double" default="100.0" required="1"> 174 <description>This is variable k_e in the soft contacts paper. Its unit is N/m.</description> 175 </element> 176 <element name="damping" type="double" default="10.0" required="1"> 177 <description>Viscous damping of point velocity in body frame. Its unit is N/m/s.</description> 178 </element> 179 <element name="flesh_mass_fraction" type="double" default="0.05" required="1"> 180 <description>Fraction of mass to be distributed among deformable nodes.</description> 181 </element> 182 </element> <!-- dart --> 183 </element> <!-- soft_contact --> 184 185</element> <!-- End Surface --> 186