Darren New <dne### [at] sanrrcom> wrote:
> You start with your 3D surface and break it down into "chips": 
> triangles, for convenience, each with a normal and an 
> emissive/reflective color.

  That indeed reminds me of an alternative (but much less popular) method
for calculating radiosity.

  Instead of calculating the lighting into lightmaps, the lighting is
instead calculated at and stored in the vertices of each polygon (basically
in the same way as you would do it for each individual pixel in the
lightmap). The polygon itself is gouraud/phong-shaded using these vertex
lighting values.

  In order to get more accuracy polygons can be subdivided into smaller
polygons and radiosity lighting calculated at each of the new vertices.
This would indeed allow subdividing more at places where there is more
variation in lighting.

  AFAIK this method is not very popular because rendering lightmaps onto
polygons is much faster and efficient than rendering several orders of
magnitude more polygons (which still need gouraud/phong shading, which
is not relevantly faster than lightmapping; could even be slower).
This is especially true in real-time rendering using hardware, as polygon
counts should be minimized, possibly being replaced with more detailed
textures.

-- 
                                                          - Warp

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