This principle is obvious. The programs should do a reality simulation. They are made for it. But many programs fail in a simple reality test.
The major problem about lack of realism are tranparency and reflection. Many comercial programs (Blender, 3D Max etc..) do tranparency through alpha channel feature. Its nosense!
Alpha channel was made to be a transparent layer on Desktop Publishing programs in 2D drawing! Designers use transparent material when are'nt using the computer. Using this feature for 3D transparency can be aceptable just for simple efects that don't require depth. An 3D object must be transparent in its volume.
Refraction must be associated always with transparency. This must be a buit-in feature and not a plug-in or add-on. There should be a way to turn it off when its not desired, of course.
Marcus Geelnard's Raylab its a program that respects this principle. In Raylab the objects have tranaprency (keyword->filter) and index of refraction (keyword->ior) that are part of object's texture.
Reflection is another problem. For example let's look what Blender does as reflection feature. The user creates an "empty" object that don't apear in the scene but serves as reflection reference for the object that should be reflective. Through the coordinates of this empty object the program first calcualtes the images from the empty point of view in six directions (the six faces of a cube around the coordinaters of the empty object). Then it uses this images as the reflections that would apear in the real object. Confused? You should be. This is a great cheat to save cpu processing time.
There are two simple tests to check a program reality capabilities. The first is a simulation of a common fishbowl (those almost round) like my fishbowl image. The second is the real fractal created by infinite refelctions in perfectly or almost perfectly reflective spheres. You can see the efect in my fractal image.
Blender failed on both tests.
3D max wasn't tested yet (I don't have it).
Real 3D fail on the reflection test and passed on the refraction (Amiga version).
Raylab of course passed on both.
Now 3D passed on the refraction test and failed on reflection.
POV-ray passed on both tests.
In test: Open-FX, 3D Canvas, Anim8tor, True Space and Yafray.
