A bumpmap maps a bumpy appearance on an object
. This effect is achieved by altering the shading of the surfaces by overlaying "embossed" textures
. Second Life
has a few predefined bumpmaps that can be applied to an object as well as the "Brightness" and "Darkness" maps that are rendered based on the bright and dark areas of the object's texture. Bumpmapping can be changed via the llSetPrimitiveParams
function. The UUID
s of each bumpmap surface can be found in viewerart.ini, or here on the wiki at ClientAssetKeys
Bumpmapped prims/sides cannot also have transparency
¹ but can have shininess
¹ Ben Linden (forums): "Right now, bump mapping in SL uses the alpha channel for the 8-bit greyscale "bumpmap", and since we only support single textures, and only 32-bit textures, this means that any texture with alpha (which is always already 32-bit) can't have a bumpmap.
Now, we are reworking how we render SL, and we are considering allowing a face to have more than 1 texture associated with it - then we could allow you to have a 32-bit texture (so one with alpha) plus a bump map, or maybe something fancier, since bump maps are sooooo two years ago."