More than one question (Hybrid Back/Forward path tracing)

[Noah_]

Hi!


I'm new is lux and I wanted to know a few things about Hybrid Back / Forward path tracing (aka BiDir without MIS) and other things

1. Is this rendering method suitable for animation?

2. Is Bidir support dead?

3. With this method you can see the caustics in mirrors? If not, how would it be possible?

4. Is it possible to caustic metal objects? for example a sword or katana

5. What is the limit of the caustics of lux with those of the real world?

6. Can you put imperfect surface textures?

7. Is there a possibility that Bidir will be faster with more development?

if I can think of more questions I say them

I want to congratulate the developers for working on such a beautiful render engine that can generate spectacular caustics and to Sharlybg for the tutorials, thank you very much I learned some things

[Dade]

1. Is this rendering method suitable for animation?

There have been reports of caustic intensity variations in animations. I have never been able to replicate this problem. But in any case, it is a bug, not an intrinsic limit of the method.

2. Is Bidir support dead?

No but it lacks significative advantages over Hybrid Back/Forward path tracing: it is mostly slower.

3. With this method you can see the caustics in mirrors? If not, how would it be possible?

Yes if you enable caustic cache too.

4. Is it possible to caustic metal objects? for example a sword or katana

Yes.

5. What is the limit of the caustics of lux with those of the real world?

None I can think to.

6. Can you put imperfect surface textures?

Yes.

7. Is there a possibility that Bidir will be faster with more development?

No, BiDir traces about n^2 rays where n is the max. path depth while hybrid about n.

[Noah_]

1. Is this rendering method suitable for animation?

There have been reports of caustic intensity variations in animations. I have never been able to replicate this problem. But in any case, it is a bug, not an intrinsic limit of the method.

This worries me in a way because I see a lot of potential in this for animations.

Is it still working to resolve this error or does it have to do with the hardware of certain computers?

[Dade]

1. Is this rendering method suitable for animation?

There have been reports of caustic intensity variations in animations. I have never been able to replicate this problem. But in any case, it is a bug, not an intrinsic limit of the method.

This worries me in a way because I see a lot of potential in this for animations.

Is it still working to resolve this error or does it have to do with the hardware of certain computers?

I just need a test scene that shows the problem (here, in a viable amount of time) so I can investigate/fix what is going on.

[juangea]

I jump to that wagon, one of the most important things we do is animation, so coherence between frames is very important.

As for an example scene, maybe @lacilaci can share the scene he present here, it's flickering a lot.

viewtopic.php?f=4&t=1688&start=20

[Dade]

I jump to that wagon, one of the most important things we do is animation, so coherence between frames is very important.

As for an example scene, maybe @lacilaci can share the scene he present here, it's flickering a lot.

viewtopic.php?f=4&t=1688&start=20

Env. cache has no relation with Hybrid Back/Forward path tracing

P.S. and I must admit I don't see any flickering in this one: viewtopic.php?f=4&t=1688&start=10#p19307

[Sharlybg]

P.S. and I must admit I don't see any flickering in this one: viewtopic.php?f=4&t=1688&start=10#p19307

same here.

but it is probably this one :

https://streamable.com/d30uq

But maybe this was already fixed i haven't really follow this thread well.

[juangea]

Yes, that one.

Sorry I did not realize this was just about caustics, I was referring to flicker in general when using GI Cache or Env Cache, not just caustics cache

[Dade]

P.S. and I must admit I don't see any flickering in this one: viewtopic.php?f=4&t=1688&start=10#p19307

same here.

but it is probably this one :

https://streamable.com/d30uq

But maybe this was already fixed i haven't really follow this thread well.

This is should have been done before exposing in Blender the support for persistent cache It should work fine with persistent cache.

[juangea]

Does persistent cache takes into account time?

I mean, can it use the persistent information to increase the data for frame 2 using the data from frame 1? or can it interpolate if we calculate persistent data for frame 1,5 and 10, can it interpolate and use persistent data to extrapolate or accelerate render for frames 2,3,4,6,7,8,9?

I would like to know how it works for animation