LuxCoreRender Forums

2, Manually setting both the Lookup radius and Brute force radius scale parameters reduces 95% of flickering (manageable level) Sounds good! Another, simple interior animation: There's some visible flicker, especially on the furniture, looks like doable with better cache. But then for this kind of ...

Property debug printing can be enabled by searching for the "debug" operator in Blender, then enable the "Print Properties" option: Sorry for being stupid, but where is the search field in Blender ?? :oops: There is a python console, but without search field. :? Instead I conventionally export to ....

Yes it is an old scene made with an earlier PGI version when there was no automatic setting and it was likely used to export binaries too.
But when I reopen it in current Blender I expect the new defaults to be exported correctly

Why are you setting the values by hand ? Because of B.Y.O.B.'s suggestion: It might be possible to reduce the bias to the point where you don't notice any flickering. For example by using a smaller entry radius and/or raising the brute force radius scale (aka usage threshold scale). Just use automa...

Dade wrote: ↑

Thu Apr 11, 2019 4:06 pm

It is not not a seed related problem

Ok thanks for explanation!
So when the photon pattern is not reproducible then of course it won't be also in different frames.
The remaining question is why the variance is so high even under identical condition.

Just wonder if buiding cache for each frame will also create flickering ? That's the case now, because of different photon distribution each frame. So I'm wondering if that can be fixed somehow. I have not yet experimented with light groups in Lux but it should be possible do build a cache for each...

Ok, so here's the bunker animation with flicker :D bunker.mp4.zip and here a sequence of debug renders without camera move: bunker.gif It seems that the photon cast uses a different seed every time even if there is no change in the scene. Maybe a fixed seed could calm down things? Also blueish areas...

It might be possible to reduce the bias to the point where you don't notice any flickering. Theoretically yes. I guess scenes with a single light source could be fine tuned to unnoticeable cache variance. But there is a problem with the photon distribution especially when there is a infinite light ...

Sorry for misunderstanding, you're right. General animation of objects is not going to work with PGI. Building of the cache introduces bias which partly depends on the photon distribution. A moving object affects the photon distribution which will then in each frame lead to a different bias on the n...

Hi Luxart,
first the persistent cache must be integrated into Blender.
It's not yet ready, see comment above by B.Y.O.B.