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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
Comments [Hide comments/form]
That "apparently" link says I don't have permission to access its page. :/
-- EepQuirk (2005-01-04 17:57:45)
It probably refers to a thread on the forums that was removed during the Great Script Discussion Erase - thank Daniel Linden for that... if he's even still around.
-- ChristopherOmega (2005-01-05 20:55:58)
Removed 'Daniel'ed link.
-- WolfWings (2005-09-07 02:16:48)
Could someone add why glass is suggested for vehicles? Isn't grip generally a good idea?
-- IoneLameth (2005-12-19 04:04:40)
If by grip you mean friction, then no. In second life, vehicles are not self-propelled by applying a force in the direction opposite of desired motion, as in real life. A "mysterious force" is applied along a vector via LSL. What this means is that whereas you would need friction in real life to drive a car, because the wheels are pushing opposite the direction of motion (along the road surface), in second life, the force is just applied to the root prim of the vehicle, totally ignoring newtons laws on the subject. Theoretically, I suppose, a vehicle could be created using physics, and "equal and opposite" forces, but it would be incredibly inefficient in SL, as the physics engine currently (Havok 1.1) installed is very poor. (Or at least, being used very poorly)

Hoping that all of what I just said makes sense, having as little friction as possible in secondlife is desired, because it allows for greater energy expended to velocity generated ratios. Objects do not have infinite energy.
-- StPsaltery (2006-01-09 16:13:39)
Yup, thanks. That's quite obvious when you point it out like that:)
-- IoneLameth (2006-02-16 10:44:41)
The "Light" material is now deprecated. As of 1.9.1/1.10.0, it is now called Fullbright(Legacy); it can only be set by script, not by the Edit UI. It does not cause an object to emit light, but merely sets the textures of all the sides to Fullbright; setting an object to emit light is done in the Features tab in the edit UI, or with llSetPrimitiveParams().
-- ShirleyMarquez (2006-06-04 05:58:39)