LuxCoreRender Forums

In playing around with a recent build of 2.5, I was happy to discover that there's now a caustics pass option (I had been extracting it myself for separate denoising by subtracting all other passes from the main rendered image). Unfortunately, this has revealed some problems with 2.5...

Firstly, for some inexplicable reason, the caustics pass is barely affected by the Denoise node. Even after doing a manual extraction as before, there is hardly any effect. All other passes seem to be affected as normal. I switched back over to 2.4 and everything works as expected.

Second, there seems to be a lingering problem with the Indirect Specular pass. I've got some orange glass, and in the Indirect Spec pass it's got waaay too much blue going on for some reason. This problem also occurs in 2.4.

Not sure if either of these problems are known yet, but I figured I'd say something here in case I'm just being an idiot...lol (Edit: I'm using Blender 2.91)
I'm including a test file:

Has there been any progress with these issues?

You can denoise the caustics pass by turning off the Pixel Filter (setting it to None). Find it under Sampling > Advanced > Filter. It's probably set to Blackman-Harris at 1.50 pixels by default. That does not work well with noise from the Metropolis sampler

Ahhh, very interesting! Switching the filter to "None" did the trick, and I can now use the Denoise node in the compositor on the caustics pass...thanks so much!! Still very odd though, that it worked just fine in version 2.4 and not in 2.5...is it supposed to work as it is now, or is that a problem?

I don't suppose you have any insight into why the Specular Indirect pass has much more blue than it should...?

steveernst117 wrote: ↑Thu Feb 04, 2021 1:15 am Still very odd though, that it worked just fine in version 2.4 and not in 2.5...is it supposed to work as it is now, or is that a problem?

This: https://github.com/LuxCoreRender/LuxCore/issues/413

Maybe pixel filtering should now be disabled in BlendLuxCore by default?

B.Y.O.B. wrote: ↑Thu Feb 04, 2021 12:19 pm Maybe pixel filtering should now be disabled in BlendLuxCore by default?

Any advantage of having it enable ?

B.Y.O.B. wrote: ↑Thu Feb 04, 2021 12:19 pm Maybe pixel filtering should now be disabled in BlendLuxCore by default?

Thinking it would probably be a good solution to have an on/off checker (an option, next to present filter settings)...

kintuX wrote: ↑Thu Feb 04, 2021 1:19 pm Thinking it would probably be a good solution to have an on/off checker (an option, next to present filter settings)

This can already be done by setting the pixel filter to "None".
But yes, could be made more standard with a checkbox "use filtering" and then all filter options aside from "None" in the dropdown.

B.Y.O.B. wrote: ↑Thu Feb 04, 2021 12:19 pm Maybe pixel filtering should now be disabled in BlendLuxCore by default?

I was assuming it was already if OIDN was used