Caustics work by default, bounce limit set to 2 from the beginning makes caustics possible right away

Uniform hemisphere rejection sampling

3:52 render time, 32 samples per pixel for gi, 16 samples for shadows, cosine-weighted importance sampling

Tweaked some scene values, 32 samples for gi, 16 shadow samples, all cosine-weighted importance sampling. 261s for render

Emissive sphere added, looks great! 360p render in 60s Main thing I notice is that the reflection with the rear wall is brighter than it should be and Im not entirely why

Increasing attenuation to 4 provides a better looking scene. Still need to do the emissive surface and figure out why the reflective sphere is very dark.

Attenuation makes a difference, but the scene is still very washed out for some reason

Gloss re-applied and changed the emissive sphere to blue temporarily. Looks like the blue is in-fact showing on the right sphere. Intensity of the light turned down to 1, since I havent done gamma correction yet.

Updating the seeding and increasing sample count helped with the banding. Lowering the soft-shadow count decreased render time substantially, but the shadows look much worse. Needs gamma correction, emissive material property, and the light source render.

An interesting first result. Looks to me like the secondary ray is being stopped prematurely. Beyond some other things that are clearly wrong with this set up.