[Assimp-discussions] light data structure

[Alexander G. <ale...@gm...>]

Hello,
>  I'd prefer a very simple data structure for these, because in my 
> experience complicated tag-like structures that could contain 
> everything and nothing are rarely used by the target audience. 
Agreed. Let's support what our target audience will be using: point, 
directional and spot lights. So far we'd have these properties:

position    (INF for directional lights)
direction   (n/a for point lights)
phi/theta   (2pi for point lights)

Well .. I think it's clear that every light has a name by which it is 
referenced by a node in the graph. So position and direction are 
specified in the node's local transformation while all other parameters 
are in a separate aiLight structure!?
Then we need light colors ... specular, diffuse and ambient I think. 
Specular and Diffuse will be equal in most cases.

The difficult question is the light attenuation ... linear and quadratic?
> We'd  have to look at Collada and 3DS for what data their light and 
> camera structures contain, and then agree on a common structure that 
> covers enough of both to be useful.
Well, I don't want to know how Collada's light structures look like ... :-)
3DS and ASE fit in the structure I described above, although I'm not 
sure how they're handling light attenuation.
 
Best wishes,
Alex