First animation attempt

Started by sboerner, May 07, 2016, 01:31:38 pm

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Thanks. Working on the short movie nearly since 2 years and still adding things. This will be the final scene hopefully.


Issues with insufficient AA will usually show up as noise or "crawling" pixel effects, rather than "flickering", which I would characterize as a lager-scale effect. If you're really seeing "flicker", it's probably either a GI issue, or some kind of geometry shadow casting issue (out of frame geometry being calculated at too low a detail for example).

From what you describe, where you see flicker in displacement-based simulated "vegetation", I think there are 2 likely possibilities. Either your primary rendering detail is too low, causing geometry calculation differences between frames, or there may be spiky displacement that is crossing render tile boundaries and not getting rendered fully on some frames (which would be fixed by increasing Displacement Tolerance in the planet node). It would be really helpful to see a brief clip of this "flickering" to really be sure what is causing it.

- Oshyan


Thanks for clarifying. I would say that this is a crawling pixel effect, then, not flicker. I've been running some tests with various GI settings, and those seem to help but it's not fixed yet.

I have a recent animation that I can post later this evening that should make things more clear.


Here is a 3-second clip of two sections of the animation. In the first section the problem mainly occurs on the mountainside above the observatory structures, and to the right of the structures at about 4 o'clock. In the second section it occurs above the observatory at about 10 o'clock.

Settings were:
Quality > Detail: 0.85
Quality > AA: 14
Pixel filter: Box
Sampling > First sampling level: 1/16
Atmosphere quality: 64

It uses a GI cache with an interval of 10 frames, interpolating 5 frames.

Everything else was left at default values. (I did use the Animation Check button.)

Since I made this I've been making test renders, gradually increasing the values in the GI prepass panel (cache detail, sample quality, blur radius) and have bumped up the overall quality level to 0.9. They look promising so I'll do another 2-3 second clip.


It seems clear that the issue is coming from your very small-scale displacement. Unfortunately AA is not very effective at smoothing out those kinds of aliasing problems. I'm trying to think of what might actually do some good, aside from just really cranking up the detail (like to 1.5 or even 2!). I can tell you that even if you may feel you're seeing improvement from your increases in GI detail, they are *not* going to solve this issue and are only increasing render time further. The actual overall render quality may be better just due to improved GI, but the aliasing will remain.

One thing you might try is a softer Pixel Filter. But it wouldn't really solve the underlying issue. Being able to use real populations instead of displacement and thus raytrace the grass/vegetation effect might also help.

If you're able to share the base scene file (even without the objects) with us then I can take a closer look and see if there are other options. support AT, attachments up to 20MB in size, or you can use wetransfer,, etc.

- Oshyan


OK. You're right about the GI settings. My overnight render still had some crawling. It was improved slightly but that's probably because of the slight increase in the Quality setting. I can't imagine rendering with a quality setting higher than 1 . . . the render times are already getting prohibitive.

I did try the Cubic B Spline filter but the result was the same, just blurrier.

Give me a day or two to strip all the extra stuff out of the scene and I'll send it by email. I really appreciate the time you're spending on this. Have to say the experience has been a good introduction to the renderer.