Rendering Texels
When texturing a 3D surface (a process known as texture mapping) the renderer maps texels to appropriate pixels in the output picture. On modern computers, this operation is accomplished on the graphics processing unit.
The texturing process starts with a location in space. The location can be in world space, but typically it is in Model space so that the texture moves with the model. A projector function is applied to the location to change the location from a three-element vector to a two-element vector with values ranging from zero to one (uv). These values are multiplied by the resolution of the texture to obtain the location of the texel. When a texel is requested that is not on an integer position, texture filtering is applied.
When a texel is requested that is outside of the texture, one of two techniques is used: clamping or wrapping. Clamping limits the texel to the texture size, moving it to the nearest edge if it is more than the texture size. Wrapping moves the texel in increments of the texture's size to bring it back into the texture. Wrapping causes a texture to be repeated; clamping causes it to be in one spot only.
Read more about this topic: Texel (graphics)
Famous quotes containing the word rendering:
“Woe to the makers of literal translations, who by rendering every word weaken the meaning! It is indeed by so doing that we can say the letter kills and the spirit gives life.”
—Voltaire [François Marie Arouet] (1694–1778)