POVRay vs. Renderman/BMRT

These pages have their origin in a discussion in comp.graphics.rendering.raytracing on the relative merits of POVRay and RenderMan. Comparing the two is a little bit difficult, since one is a program and the other one an interface specification which is implemented by different programs, like Pixar's Photorealistic RenderMan or PRMan and Larry Gritz' now defunct Blue Moon Rendering Tools. If you want to do your own experiments, try one of the renderers in the list of renderers at the RenderMan Repository.

In most of what follows I used the raytracer from BMRT (which was shareware) as an example for a RenderMan compliant renderer.

Shading

POV is a great program, but the one thing that won me over to a renderman compliant renderer was the shading language, which gives you an enormous flexibility.

	Surfaces are parametrized, so textures can follow arbitrary surfaces.
	You can map images onto surfaces in many ways, in my example I use a map to generate an image of a globe.

Geometry

Height fields are convenient objects in POV.

Rendering software for most images:

POVRay 3.0