246 lines
12 KiB
Plaintext
246 lines
12 KiB
Plaintext
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<element name="surface" required="0">
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<description>The surface parameters</description>
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<element name="bounce" required="0">
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<description></description>
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<element name="restitution_coefficient" type="double" default="0" min="0.0" max="1.0" required="0">
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<description>Bounciness coefficient of restitution, from [0...1], where 0=no bounciness.</description>
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</element>
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<element name="threshold" type="double" default="100000" required="0">
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<description>Bounce capture velocity, below which effective coefficient of restitution is 0.</description>
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</element>
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</element> <!-- End Bounce -->
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<element name="friction" required="0">
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<description></description>
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<element name="torsional" required="0">
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<description>Parameters for torsional friction</description>
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<element name="coefficient" type="double" default="1.0" min="0.0" required="0">
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<description>
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Torsional friction coefficient, unitless maximum ratio of
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tangential stress to normal stress.
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</description>
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</element>
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<element name="use_patch_radius" type="bool" default="1" required="0">
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<description>
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If this flag is true,
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torsional friction is calculated using the "patch_radius" parameter.
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If this flag is set to false,
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"surface_radius" (R) and contact depth (d)
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are used to compute the patch radius as sqrt(R*d).
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</description>
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</element>
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<element name="patch_radius" type="double" default="0" min="0.0" required="0">
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<description>Radius of contact patch surface.</description>
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</element>
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<element name="surface_radius" type="double" default="0.0" min="0.0" required="0">
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<description>Surface radius on the point of contact.</description>
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</element>
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<element name="ode" required="0">
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<description>Torsional friction parameters for ODE</description>
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<element name="slip" type="double" default="0.0" required="0">
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<description>
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Force dependent slip for torsional friction,
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equivalent to inverse of viscous damping coefficient
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with units of rad/s/(Nm).
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A slip value of 0 is infinitely viscous.
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</description>
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</element>
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</element> <!-- End ODE -->
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</element> <!-- End torsional -->
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<element name="ode" required="0">
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<description>ODE friction parameters</description>
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<element name="mu" type="double" default="1" min="0.0" required="0">
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<description>
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Coefficient of friction in first friction pyramid direction,
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the unitless maximum ratio of force in first friction pyramid
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direction to normal force.
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</description>
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</element>
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<element name="mu2" type="double" default="1" min="0.0" required="0">
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<description>
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Coefficient of friction in second friction pyramid direction,
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the unitless maximum ratio of force in second friction pyramid
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direction to normal force.
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</description>
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</element>
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<element name="fdir1" type="vector3" default="0 0 0" required="0">
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<description>
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Unit vector specifying first friction pyramid direction in
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collision-fixed reference frame.
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If the friction pyramid model is in use,
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and this value is set to a unit vector for one of the
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colliding surfaces,
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the ODE Collide callback function will align the friction pyramid directions
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with a reference frame fixed to that collision surface.
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If both surfaces have this value set to a vector of zeros,
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the friction pyramid directions will be aligned with the world frame.
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If this value is set for both surfaces, the behavior is undefined.
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</description>
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</element>
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<element name="slip1" type="double" default="0.0" required="0">
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<description>
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Force dependent slip in first friction pyramid direction,
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equivalent to inverse of viscous damping coefficient
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with units of m/s/N.
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A slip value of 0 is infinitely viscous.
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</description>
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</element>
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<element name="slip2" type="double" default="0.0" required="0">
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<description>
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Force dependent slip in second friction pyramid direction,
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equivalent to inverse of viscous damping coefficient
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with units of m/s/N.
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A slip value of 0 is infinitely viscous.
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</description>
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</element>
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</element> <!-- End ODE -->
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<element name="bullet" required="0">
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<element name="friction" type="double" default="1" min="0.0" required="0">
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<description>
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Coefficient of friction in first friction pyramid direction,
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the unitless maximum ratio of force in first friction pyramid
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direction to normal force.
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</description>
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</element>
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<element name="friction2" type="double" default="1" min="0.0" required="0">
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<description>
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Coefficient of friction in second friction pyramid direction,
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the unitless maximum ratio of force in second friction pyramid
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direction to normal force.
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</description>
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</element>
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<element name="fdir1" type="vector3" default="0 0 0" required="0">
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<description>
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Unit vector specifying first friction pyramid direction in
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collision-fixed reference frame.
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If the friction pyramid model is in use,
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and this value is set to a unit vector for one of the
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colliding surfaces,
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the friction pyramid directions will be aligned
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with a reference frame fixed to that collision surface.
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If both surfaces have this value set to a vector of zeros,
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the friction pyramid directions will be aligned with the world frame.
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If this value is set for both surfaces, the behavior is undefined.
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</description>
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</element>
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<element name="rolling_friction" type="double" default="1" required="0">
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<description>Coefficient of rolling friction</description>
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</element>
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</element> <!-- End Bullet -->
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</element> <!-- End Friction -->
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<element name="contact" required="0">
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<description></description>
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<element name="collide_without_contact" type="bool" default="0" required="0">
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<description>Flag to disable contact force generation, while still allowing collision checks and contact visualization to occur.</description>
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</element>
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<element name="collide_without_contact_bitmask" type="unsigned int" default="1" required="0">
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<description>Bitmask for collision filtering when collide_without_contact is on </description>
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</element>
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<element name="collide_bitmask" type="unsigned int" default="65535" required="0">
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<description>Bitmask for collision filtering. This will override collide_without_contact</description>
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</element>
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<element name="category_bitmask" type="unsigned int" default="65535" required="0">
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<description><![CDATA[Bitmask for category of collision filtering. Collision happens if ((category1 & collision2) | (category2 & collision1)) is not zero. If not specified, the category_bitmask should be interpreted as being the same as collide_bitmask.]]></description>
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</element>
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<element name="poissons_ratio" type="double" default="0.3" required="0">
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<description>
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Poisson's ratio is the unitless ratio between transverse and axial strain.
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This value must lie between (-1, 0.5). Defaults to 0.3 for typical steel.
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Note typical silicone elastomers have Poisson's ratio near 0.49 ~ 0.50.
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For reference, approximate values for Material:(Young's Modulus, Poisson's Ratio)
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for some of the typical materials are:
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Plastic: (1e8 ~ 3e9 Pa, 0.35 ~ 0.41),
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Wood: (4e9 ~ 1e10 Pa, 0.22 ~ 0.50),
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Aluminum: (7e10 Pa, 0.32 ~ 0.35),
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Steel: (2e11 Pa, 0.26 ~ 0.31).
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</description>
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</element>
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<element name="elastic_modulus" type="double" default="-1" required="0">
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<description>
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Young's Modulus in SI derived unit Pascal.
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Defaults to -1. If value is less or equal to zero,
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contact using elastic modulus (with Poisson's Ratio) is disabled.
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For reference, approximate values for Material:(Young's Modulus, Poisson's Ratio)
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for some of the typical materials are:
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Plastic: (1e8 ~ 3e9 Pa, 0.35 ~ 0.41),
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Wood: (4e9 ~ 1e10 Pa, 0.22 ~ 0.50),
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Aluminum: (7e10 Pa, 0.32 ~ 0.35),
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Steel: (2e11 Pa, 0.26 ~ 0.31).
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</description>
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</element>
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<element name="ode" required="0">
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<description>ODE contact parameters</description>
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<element name="soft_cfm" type="double" default="0" required="0">
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<description>Soft constraint force mixing.</description>
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</element>
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<element name="soft_erp" type="double" default="0.2" required="0">
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<description>Soft error reduction parameter</description>
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</element>
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<element name="kp" type="double" default="1000000000000.0" required="0">
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<description>dynamically "stiffness"-equivalent coefficient for contact joints</description>
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</element>
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<element name="kd" type="double" default="1.0" required="0">
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<description>dynamically "damping"-equivalent coefficient for contact joints</description>
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</element>
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<element name="max_vel" type="double" default="0.01" required="0">
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<description>maximum contact correction velocity truncation term.</description>
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</element>
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<element name="min_depth" type="double" default="0" required="0">
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<description>minimum allowable depth before contact correction impulse is applied</description>
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</element>
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</element> <!-- End ODE -->
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<element name="bullet" required="0">
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<description>Bullet contact parameters</description>
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<element name="soft_cfm" type="double" default="0" required="0">
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<description>Soft constraint force mixing.</description>
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</element>
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<element name="soft_erp" type="double" default="0.2" required="0">
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<description>Soft error reduction parameter</description>
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</element>
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<element name="kp" type="double" default="1000000000000.0" required="0">
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<description>dynamically "stiffness"-equivalent coefficient for contact joints</description>
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</element>
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<element name="kd" type="double" default="1.0" required="0">
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<description>dynamically "damping"-equivalent coefficient for contact joints</description>
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</element>
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<element name="split_impulse" type="bool" default="1" required="1">
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<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>
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</element>
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<element name="split_impulse_penetration_threshold" type="double" default="-0.01" required="1">
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<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>
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</element>
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</element> <!-- End Bullet -->
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</element> <!-- End Contact -->
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<!-- for deformable bodies -->
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<element name="soft_contact" required="0">
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<element name="dart" required="0">
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<description>soft contact pamameters based on paper:
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http://www.cc.gatech.edu/graphics/projects/Sumit/homepage/papers/sigasia11/jain_softcontacts_siga11.pdf
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</description>
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<element name="bone_attachment" type="double" default="100.0" required="1">
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<description>This is variable k_v in the soft contacts paper. Its unit is N/m.</description>
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</element>
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<element name="stiffness" type="double" default="100.0" required="1">
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<description>This is variable k_e in the soft contacts paper. Its unit is N/m.</description>
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</element>
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<element name="damping" type="double" default="10.0" required="1">
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<description>Viscous damping of point velocity in body frame. Its unit is N/m/s.</description>
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</element>
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<element name="flesh_mass_fraction" type="double" default="0.05" required="1">
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<description>Fraction of mass to be distributed among deformable nodes.</description>
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</element>
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</element> <!-- dart -->
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</element> <!-- soft_contact -->
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</element> <!-- End Surface -->
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