ingenious wrote:No matter how long what runs? The algorithm, as presented in the paper, always runs a finite amount of time for a fixed number of initial virtual point lights.

In the paper they put it in the context of a ray tracer that is still shooting eye rays. So I was imagining that e.g. antialiasing and DoF would still be computed with monte carlo ray tracing. But you're right, that's not actually part of the algorithm itself. So more simply, it just won't converge.

ingenious wrote:Every unbiased method has been originally described as a single-pass finite-sample algorithm. Progressive rendering with an "outer loop" came much later, so in that regard Lightcuts is on the same "level" as path tracing.

Yeah. Although I think there is a difference in presenting an algorithm as one-pass, and presenting an algorithm as arbitrarily many passes. Both are finite, but the latter typically implies some kind of limit solution.

EDIT: Err... mixing up my terminology. The above should have read:

"Yeah. Although I think there is a difference in presenting an algorithm as single-sample, and presenting an algorithm as arbitrarily many samples. Both are finite, but the latter typically implies some kind of limit solution."

Or something along those lines, anyway.