llSetPhysicsMaterial

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Summary

Function: llSetPhysicsMaterial( integer mask, float gravity_multiplier, float restitution, float friction, float density );

Used to set the physical characteristics of an object.

• integer mask bitwise combination of DENSITY, FRICTION, RESTITUTION, and GRAVITY_MULTIPLIER and specifies which floats to actually apply
• float gravity_multiplier range [-1.0, +28.0], default: 1.0
• float restitution range [0.0, 1.0], default: [0.3, 0.9] [1]
• float friction range [0.0, 255.0], default: [0.2, 0.9][1]
• float density range [1.0, 22587.0] kg/m^3, default: 1000.0

The default values for friction and restitution depend upon the material type.

mask Flags V Description
DENSITY 1 Indicates that density parameter is enabled and will override the previous value.
FRICTION 2 Indicates that friction parameter is enabled and will override the previous value.
RESTITUTION 4 Indicates that restitution parameter is enabled and will override the previous value.
GRAVITY_MULTIPLIER 8 Indicates that gravity_multiplier parameter is enabled and will override the previous value.

Caveats

  • A collision between two objects with restitution 1.0 will still not be perfectly elastic due to damping in the physics engine.
  • Using PRIM_MATERIAL to set the material type will reset the values for friction and restitution to that material's defaults.
  • llSetPhysicsMaterial silently fails if called from an attachment.
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Examples

  • Basic Example
     llSetPhysicsMaterial(FRICTION, 1.0,0.9,0.1,0.5); // Sets FRICTION to 0.1
  • Multiple Settings
     llSetPhysicsMaterial(GRAVITY_MULTIPLIER | RESTITUTION | FRICTION | DENSITY, 0.5,0.9,0.1,1.0);

See Also

Constants

•  PRIM_MATERIAL

Functions

•  llGetPhysicsMaterial
•  llSetBuoyancy Set how gravity interacts with an object. Works in attachments (changes are applied to the avatar).

Deep Notes

Material Defaults

Using PRIM_MATERIAL changes the the values for friction and restitution to the values listed for the material type.

material Flags Description Friction Restitution
PRIM_MATERIAL_STONE 0 stone 0.8 0.4
PRIM_MATERIAL_METAL 1 metal 0.3 0.4
PRIM_MATERIAL_GLASS 2 glass 0.2 0.7
PRIM_MATERIAL_WOOD 3 wood 0.6 0.5
PRIM_MATERIAL_FLESH 4 flesh 0.9 0.3
PRIM_MATERIAL_PLASTIC 5 plastic 0.4 0.7
PRIM_MATERIAL_RUBBER 6 rubber 0.9 0.9
PRIM_MATERIAL_LIGHT 7 light, DEPRECATED: Looks the same as [ PRIM_FULLBRIGHT, ALL_SIDES, TRUE ] 0.6 0.5

llSetPhysicsMaterial cannot use these flags.

History

Date of Release 23/09/2011
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Tests

•  Physics Material Settings test

Footnotes

  1. ^ The default values for friction and restitution depend upon the prim's material.
  2. ^ The ranges in this article are written in Interval Notation.

Signature

function void llSetPhysicsMaterial( integer mask, float gravity_multiplier, float restitution, float friction, float density );
integer DENSITY = 1;//range 1.0 to 22587.0 (in kg/m^3), default: 1000.0
integer FRICTION = 2;//range 0.0 to 255.0, default values are in the range 0.2 to 0.9
integer RESTITUTION = 4;//range 0.0 to 1.0, default values are in the range 0.3 to 0.9 (note, a collision between two objects with restitution 1.0 will still not be perfectly elastic due to damping in the physics engine)
integer GRAVITY_MULTIPLIER = 8;//range -1.0 to +28.0, default: 1.0