LuxCoreRender Forums

happyboy wrote: ↑Tue Jun 25, 2019 12:02 pm I've tried it with a bathroom scene (there is a glass shower and a mirror), which looks good. However, all my emissive objects are black. Is it intended or a bug? After disabling Hybrid Back/Foward path tracing, these objects are emissive again. I'm using OCL and partition = 0 (CPU only do light paths).

You may be using a version with an initial bug, it has been fixed so try to update your binaries again.

FarbigeWelt wrote: ↑Tue Jun 25, 2019 11:41 am This is a good question. Looks like BiDir behavior. BiDir does not mirror everything, e.g. scattered laser beams, it looks like BiDir only renders with max depth of one in these cases. Is there any good reason?

You can not connect a specular path vertex with the eye (or the light), it is just not possible: it is a delta reflection.

B.Y.O.B. wrote: ↑Tue Jun 25, 2019 10:12 am I have exposed this feature in BlendLuxCore.

Dade wrote: ↑Tue Jun 25, 2019 11:11 am I added the support for rendering glossy caustics.

Thanks guys, great progress!
I could not get glossy caustics from Blender, so this feature is yet to be exposed?

Have started an animation, but when motion blur is activated light tracing does not work

epilectrolytics wrote: ↑Tue Jun 25, 2019 3:52 pm I could not get glossy caustics from Blender, so this feature is yet to be exposed?

Check if your binary already includes the feature.
I have not yet exposed the new "path.hybridbackforward.glossinessthreshold" parameter, but it will just use the default value, so it should already work in Blender.

Glossy caustics didn't work for me either in Blender, so I went after it, and it seems, that it dosen't work without the "path.hybridbackforward.glossinessthreshold" parameter.

- Didn't work in Blender
- I exported the scene from Blender => didn't work in LuxCore UI
- I added "path.hybridbackforward.glossinessthreshold = 0.05" line in render.cfg => now it works in LuxCore UI

Ah ok, the default is 0, I assumed it to be 0.05 because of Dade's example.

B.Y.O.B. wrote: ↑Tue Jun 25, 2019 6:21 pm Ah ok, the default is 0, I assumed it to be 0.05 because of Dade's example.

You are correct, it is a bug, both the code for "path.hybridbackforward.partition" and "path.hybridbackforward.glossinessthreshold" default values is wrong (https://github.com/LuxCoreRender/LuxCor ... r.cpp#L816), I will fix it. It is prebably a left over from some debug session.

I might have found a bug:
This is a scene with metal material, roughness 0.1, glossiness threshold set to 0.2 so the glossy reflections of this material are handled by the light tracer.
However it looks like the normal path tracer is also still tracing these reflections because they are very noisy.
I did a render with only light paths and the reflection is much cleaner there than in the combined result.
(10 spp renders)

Is this intended behaviour?

In newer LuxCore UI LightCPU engine doesn't trace certain paths. The image in the mirror doesn't seen at all.
The version from June 21 of is working fine, the June 25 is no longer.