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

Use this forum for general user support and related questions.
Forum rules
Please upload a testscene that allows developers to reproduce the problem, and attach some images.
User avatar
Dade
Developer
Developer
Posts: 5672
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

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

Post by Dade »

juangea wrote: Wed Jan 29, 2020 10:40 am Does persistent cache takes into account time?
Only for the motion blur time of the current frame (see below).
juangea wrote: Wed Jan 29, 2020 10:40 am 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?
LuxCore has no information at all about animation, it sees only the current frame to render. The only time related information is about motion blur. So the only time related information it has is about the animation happening inside the frame it is currently rendering.
juangea wrote: Wed Jan 29, 2020 10:40 am I would like to know how it works for animation :)
Persistent caches should be used with static environments: for instance a camera fly trough is the typical application and they are very effective because you amortize the cache pre-processing cost over all the frames you have to render.
Support LuxCoreRender project with salts and bounties
juangea
Donor
Donor
Posts: 332
Joined: Thu Jan 02, 2020 6:23 pm

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

Post by juangea »

ok, thanks for the clarification :)

May be good to have the cache, even if it's not persistent, to take into account the previous frame to avoid probelms or is it stable as it is?

(just curiosity)
tokiop
Posts: 42
Joined: Fri Apr 13, 2018 8:11 pm

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

Post by tokiop »

Sharlybg wrote: Wed Jan 29, 2020 8:41 am
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.
Also, in the streamable one the light/sun is animated, so persisting cache might be discarded / irrelevant ?
User avatar
Dade
Developer
Developer
Posts: 5672
Joined: Mon Dec 04, 2017 8:36 pm
Location: Italy

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

Post by Dade »

tokiop wrote: Wed Jan 29, 2020 4:17 pm Also, in the streamable one the light/sun is animated, so persisting cache might be discarded / irrelevant ?
Yes, I explained in the original thread why using a persistent cache with with animated "things" can lead to problems.
Support LuxCoreRender project with salts and bounties
Post Reply