Material
In traditional 3D, material makes up a
polygon's
surface, specifying its
geometry style,
color,
texture,
lighting, etc.
In
SL, each individual
prim can be made of one of several different material types in a more
physical sense. Material type can be changed by editing a prim/object, going to the "Object" tab, and clicking the "Material"
drop-down menu in the bottom left corner of the window. Each material has its own set of characteristics, such as default
collision sounds and
friction, and possibly some other properties relating to the
physics engine, though details are unclear.
The following list is sorted by friction, not the order it appears in the edit box.
Material | Description |
Light | Emits light visible when the "Local Lighting" preference is enabled (can cause client slowdown if abused). Prevents shadow on the surface of a prim made from this material. Has the least friction, slightly less than glass. Deprecated, will show as "Fullbright(legacy)" for lit prims before SL 1.9.1 |
Glass | Fairly clearly has the least friction (useful for roads, vehicles, or for sliding down) |
Metal | Slightly more friction than glass. |
Plastic | More friction than glass and metal. |
Wood | Default material all new prims are made of. More friction than plastic. |
Rubber | More friction than wood. Contrary to previous belief, this material does bounce higher. After it bounces, it will continue to bounce until it runs out of energy. Also has a rubber-like structure (as in, if you drop it, it will jiggle.) Possibly loses less energy in collisions, though; someone could check that |
Stone | More friction than rubber. |
Flesh | Seems to have slightly more friction than stone. |
Useful Tips: When using "Light" to light a room up at night, a combination of
llSetPrimitiveParams and
llGetTimeOfDay can be used to change the material from "Light" to something else at the appropriate times. Also, instead of making every prim material "Light", make a separate, invisible,
phantom light prim to simulate the light source.
The following table was generating by applying an impulse force to a cube and measuring the resulting friction force.
Material vs Glass | coefficient of friction |
Glass | 0.20 |
Metal | 0.25 |
Plastic | 0.30 |
Wood | 0.36 |
Stone | 0.42 |
Rubber | 0.44 |
Flesh | 0.45 |
Approximating a vehicle on a road (rubber on stone) the coefficient of friction is 0.86.
Hopefully other Wiki users will update this page with facts about the different material types to fill in what we don't have listed. As more details are obtained, the Details column could probably be expanded to separate categories like friction, 'bounce', and other such things. Feel free to add in what you know, or comment in what you suspect.
Prim |
Friction