Suppose you ave a model inside a bounding box. In wich place must be positioned a light in order to achieve a reasonable illumination effect in dependence of the type of projection selected by the user? Is possible to compute this position knowing only the bounding box, model and projection matrix? Thanks for the collaboration and my apologize for the poor english…
It’s un-clear what “reasonable” means. If you can define “reasonable” mathematically, then I suppose that your problem is solved in that definition – just implement that!
Lacking that, I would set illumination to be directional, and to come from behind/above/totheleftof the viewpoint (assuming you keep track of VIEW different from MODEL in MODELVIEW).