Ray tracing can turn good modeling artistry into a beautiful picture. However, it is extremely computationally intensive, with somewhat unpredictable compute time, which makes it inappropriate for real time rendering of scenes.

It use to be that ray tracing was the only way to get a photorealistic scene. As the simulation industry grew, it began to demand near-real time 3D rendered scenes, so faster methods than ray tracing had to be created.

It started with constant shading which doesn't look real at all, but is almost good enough. Then Gouraud shading, Phong shading, and texture mapping were developed, which while not quite as good as ray tracing, look real enough, and are reasonably fast, and can be done in real time with a bit of hardware assist.

Although these methods still don't look as good as ray tracing, they make a good complement. Most advanced solid modeling programs support one or more of these fast methods in addition to ray tracing.