LuxCoreRender Forums

Hello. I've got two quick questions.

*) I'd appreciate if somebody could explain the raltionship between "Total Path Depth" and the singular depth values. Will it cap the values (Diffuse, Glossy, Specular) indivually or the total sum of them? Let's say my "Total Path Value" is 16 and my singular values are at 8 each. Will the be affected by the "Total Path Value" or not?

*) Is it possible for a light to be visible to specular reflections only without affecting the diffuse appearance?

Cheers,
Andreas

AndreasResch wrote: Thu Jul 19, 2018 1:07 pm *) I'd appreciate if somebody could explain the raltionship between "Total Path Depth" and the singular depth values. Will it cap the values (Diffuse, Glossy, Specular) indivually or the total sum of them? Let's say my "Total Path Value" is 16 and my singular values are at 8 each. Will the be affected by the "Total Path Value" or not?

I think it caps the sum.
So if the individuals are 8 and the total is 16, you can have light paths of length 16 if e.g. 8 are diffuse and 8 are glossy bounces.
At least that's my guess.
See the attached example.

AndreasResch wrote: Thu Jul 19, 2018 1:07 pm *) Is it possible for a light to be visible to specular reflections only without affecting the diffuse appearance?

I don't think so.
You can only hide some lights from indirect light rays, but not having a direct light influence.
But it might be possible by using render layers and compositing.

Hey.

Thanks for the information. I was assuming something like that. What happens, if the values of the individual depths are different though. How is it decided, which one gets capped and by how much?

Here's an example ...
Diffuse: 4
Glossy: 8
Specular: 16
Total Depth: 20

Cheers,
Andreas

I don't know. Dade can probably help you.

AndreasResch wrote: Fri Jul 20, 2018 3:02 pm Thanks for the information. I was assuming something like that. What happens, if the values of the individual depths are different though. How is it decided, which one gets capped and by how much?

Here's an example ...
Diffuse: 4
Glossy: 8
Specular: 16
Total Depth: 20

They are all independent conditions, as soon was one is over the cap, LuxCore stops tracing the path. Each path bounce is classified according the type of material. All the counters start from 0 and each bounce of the eye (and light in the case of BiDir) path:

1) the total is incremented by 1;
2) diffuse or glossy or specular counter is incremented by one according the kind of material.

Once one of the counters is over the cap, the path is terminated.

Thanks, Dade. I think I've got it now.