Simulation of a light source in a scene?

Question

I have photos of LEGO scenes with several objects, walls, surfaces etc. in them. Currently, there are no lights in the scenes, except for the lapms that light the scene from outside. The goal is to add glowing objects like computer screens, lamps etc. that are inside of the scene.

Since I don't have real miniature lamps and lights, I would like to simulate the effect that added lights and lamps would have on objects. For example, how is the face of a Lego minifigure affected by the glowing of a blue screen in front of it?

I am not aiming at perfect results (no physically correct phong/reflection/caustics etc.), rather at methods that yield reasonable approximations of glowing and reflection effects. My tools are Gimp, Inkscape, Krita, ImageMagick, POV-Ray and Linux scripting knowledge.

At the moment, I am thinking of adding coloured, semi-transparent layers to selected areas of the images, but maybe there are graphic or painting "tricks" available, that give good results.

Any help is appreciated!

Answer 1

Have a look at Filters>Light and Shadows>Lighting effects and especially at the Environment map tab (which is a picture whose tints are reflected in the object). You may also want to add a bump map to help create the right shadows.