I have to start this topic cause there are too many unsolved questions about map flickering through an animation. Displacement maps as well as bumps are flickering te most. I have experimented with almost all available parameters, and of course with unsuccessful results.
**AA settings appears dont change the result (-2.0 -1.1 0.2 1.3) - it's flickering in most of this combinations (with jitter on)
**approx settings and presets dont help (L-dist-angle in several combinations actually managed to decrease flickering - but not solved it completely)
**texture filtering [with the file maps (including baked ones)] (*haven't tried eliptical filtering yet, with this issue)] only smooths the edges but not solving the flickering
**procedural textures appears the worst (hence the baking experiments with different res', and different filter values)
These are all things I've experimented with (maybe I forgot something).
I know there is some solution, but it's the odd thing that is very hard to find an answer in the massive docs all over the net, for this is an issue that cannot be omited.
Well yes this ones hard, theres no universal solution. and its a trade off thing on the other hand it flickers under certain conditions but then again would result in too long computational overhead. There is however a limiting rule that states thet if the frequency of variation in the texture is lower than your sampling sampling you will get noisy results which leads to flicker and bad aaing. And theres NO WAY AROUND THIS EXCEPT INCREASING SAMPLING.
AA Sampling does not affect displacement just displacement settings. so to increase this you need to chage your displacement settings.
However the best way would be to filter the texture so its not so singular in sample. Ideally the texture itself would need to integrate the size of the sample. Often you cannot do this however sop youd need to oversample the texture is simplest.
The strange thing appeared when mib_t.x_turbulence is used as a displace map through mib_col._intensity. : There weren't any flickering. But, at the other side, when some other procedurals were used (for instance - maya's mountain or fractal), flicker makes garbage of frames.
File textures are not that efficient in my case of displacement, so I have to handle with procedurals.
So Joojaa, my question would be on your advise to "oversample" the texure - what exactly do U mean "oversample" and match with global sample rate? Only options which can be found are "filtering" in the file textures attributes, mib_texture_filter_lookup operator and nothing similar for procedurals (if we're talking about same thing). So how to handle that?
Well theres a filter paremeter in the effects part. As i said the developper of the procedural needs to do it.
However the problem in the frequency of your mountain texture, bring it down a bit, then set your approximation edior displacement into some pregenerating mode that is to say not fine as this will keep the sampling static.
Of course, I knew for the filter parameter but I thought there was something I've missed (when you mentioned the "oversampling" it sounded unfamiliar to me).
It's very unpleasant - all this issue: you build a scene, finish the animation - but you actually don't have it - it's useless. Inspite all mentioned parameter corrections, and the things settled on their places - but there's still that inexhaustible flickering. I've succeeded to decrease the problem a little, and if in some case the texture is repeated couple of times (in the remap node) - there's no space for hope of decent result!
Thank U Joojaa again, I'll keep on trying to find the best solution.
Read it its a good primer, for understanding the underlying problem. Of frequancy and how it relates to things.
Supersampling is taking the same image and oset it by a subsample for a better approximation of the thing. However use a standard diplacement approximation that not fine uses up more memory but is guaranteed to not flicker that is unless you animate the texture.
yes, one of my all time favorites, the first section is well written. But in general i like the pixars approach on stuff. my personal second best favorite is in the siggraph paper year after that in section called shading fish guts its at the end of this bundle: