Animation rendering homogeneity

[ackbahr]

Hi! I'm rendering a big animation (800 frames), and I was wondering if there was a way to use a non-random sample distribution (or let's say a random one, but the SAME for ALL pictures), so the pictures look more alike?
Thank you very much!
Ack

[jeanphi]

Hi,

Render with the lowdiscrepancy sampler in debug mode (-d switch on the command line) with only 1 thread per render (-t 1 on the command line), all random seeds will then be the same. The 1 thread thing is not really a penalty since instead of using more threads per image you can compute more images in parallel.

Jeanphi

[ackbahr]

Does that mean I'm supposed to start 800 instances of luxconsole in parallel?

[Chab]

No. If you have two processors, save two files. One from frame 1 to 799 with step 2 and the second one from frame 2 to 800 with step 2. It will work if the parameter step is supported with the script.

[Radiance]

Indeed, i've been thinking about adding a command line flag/switch to ensure same seeds for all threads for rendering animations, i'll see if i can add one asap and maybe it will be in the next weekly build.

Radiance

[ackbahr]

Radiance, I must say this would be great, as now my anim looks a bit like a 1905 movie, with all the flickering.... If you happen to do anything about autoexposure, I'd love it too!
Thanks a lot for all the work and your answers....
Ack

[dougal2]

You can reduce the flickering by not using Reinhard tonemapping. I'm not sure if Lux has other tonemappers available, or how to set them up.

[jeanphi]

Hi,

Actually Reinhard won't create flickering but rather intensity variations across frames. Those should however be small if the render has converged sufficiently.
To avoid this problem you'd need a non adaptative tonemapper (like film sensitivity and exposure duration) but lux currently doesn't have any. I'll see if I can find enough data to hack something.

Jeanphi

[zsouthboy]

I would be interested in some actual data/examples of the rng seed being set the same vs. different between frames being better or worse from one another.

The scene is changing regardless, shouldn't the result be roughly the same (as in, there is no consequence to using different seeds?)

[ackbahr]

Here is an example of some pictures in my animation. As you can see, the result is really too various to give a comfortable result!
(it's not obvious like this : to be aware of it, download and look at them one after the other)