> Since the composition of diffeomorphisms is a diffeomorphism, large programs (like ray-tracers) will be differentiable as a result. That's just bs. If you ju

> Since the composition of diffeomorphisms is a diffeomorphism, large programs (like ray-tracers) will be differentiable as a result. That's just bs. If you just read the ray-tracer article it clearly states that f(scene parameters) -> image is not differentiable -- simply put because of sharp edges of objects being rendered. Also the word `diffeomorphism` makes no sense at all in this context.