Dynamic Lightmaps

Dynamic lightmapping can be created using texgen.
The lightmap can then be applied to a scene 'externally' - without the individual objects having texture coordinates or otherwise expecting a texture.

Basic scene
Light texture
Result

Generating S & T texture coordinates via 

        S = x
        T = z

will cause the light map to lie in the X/Z plane, as if it were projected straight down the Y axis.

If the light is currently located at (LX, LY, LZ), then 

        S = x - LX
        T = z - LZ

will cause the texture to move with the light. The (0,0) texture coordinate will be located directly below the light.

Offsetting the coordinates by 0.5: 

        S = x - LX + 0.5
        T = z - LZ + 0.5

will center the lightmap - texture coordinate (0.5, 0.5) will be directly below the light.

Finally, 

        S = 0.1 * x - 0.1 * LX + 0.5
        T = 0.1 * z - 0.1 * LZ + 0.5

will change the lightmap's size - it will cover a 10 x 10 unit area of the scene, rather than a 1 x 1 unit area.


Examples:



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