Transparency and shadow

For transparent or translucent objects, when the light intersects with the surface of the object, reflection and refraction will generally occur, and the refrected light will pass through the object and shoot out in the other side of the object, forming transmission light. If the viewpoint is in the direction of the refracted light, the transmitted light can be seen. The most common method is color harmony method, which does not consider the light refraction of the transparent body and the thickness of the transparent object itself. The light does not change direction through the surface of the object, so it can simulate flat glass.

Shadow is a very common illumination phenomenon in real life. It is a dark area behind an object caused by the occlusion of a light source. In photorealistic graphics, shadows can provide the position and orientation information of objects, which can reflect the relationship between objects and increase the stereo effect and reality of graphics.

When the shadow area of the object is known, it can be combined with the simple illumination model. For the polygon of the object surface, if it is inside the shadow area, then the light intensity of the polygon is only the ambient light, and the following several light intensity are zero, otherwise the light intensity is calculated by the normal model. In this way, the shadow can be introduced into the simple light model, and the realistic graphics can be more layered.

Your task

What is the Transparent Illumination model?

Share your thoughts and ideas in the comments below.