Right now I have only a simple scene to show the result of the integrator, later I'll focus more on the other part of the tracer (bsdf, weighting system, sampling, performance etc).
Here's a comparison image of the PPM integrator
First one has only one photon gathering pass, and second with 10 photon gathering pass. Each pass has 200K photons.
Direct lighting and indirect light are not decoupled, which makes the most mathematical sense to me.
Well I just realized this is not convincing enough. I should do a comparison between 200K photons per pass with 10 pass and 2M photon with 1 pass, and that would be my next post with other features added.