Strange bug in animation rendering

[Nico3333fr]

Hi Terrageners,

I have a weird bug in an animation rendering, see this file : http://www.nicolas-hoffmann.net/animations/ice.mp4 (24 Mb)

I supposed that I have badly parametered something, but don't know what.  

In case of, I've attached the tgd file.

Thanks for helping me to find the problem.  

Nicolas

[Seth]

you have detail blending 0 and Ray detail region padding 0 for this animation ?
I don't think the problem comes from that settings but I would  change those value for detail blending 1 and Ray detail region padding 0.25 just to be sure.

[Tangled-Universe]

Yes I would do that too. Detail blending blends different levels of subdivisions and I this look like a sub-division problem of surfaces which are being reflected.
They're not always off camera here, for which you'd require the ray detail region blending, theoretically speaking.

Other things you could consider is disabling "jitter shading points" in the render subdiv settings if the above suggestions don't help.
Other jittering options in the render may also cause some problems, since they can create gaps in geometry or shade things based on jitter = randonmness which adds complexity to deal with.

[dandelO]

The problem is 'reflection softness' in 'Reflective shader 01'.

Disable this by setting it back to '0', it is set to 0.05 in your .tgd and there are only 4 reflection samples used.
Quality samples are used in the reflective shader when you have softness enabled and even then, bumping the sample quality up to maximum will only give you longer render times and still nasty results when multi-thread rendering.
The only way I've been able to get a consistent result with the softness parameter is to use a single thread to render the entire image in one pass(i.e. use bucket sizes without auto-reduction at your image resolution). Each time a bucket renders beside another, the reflection softness is calculated differently per tile.

If you'd like some other way to create a soft reflection, I made a method here, feel free to use/edit it to suit your scene; http://forums.planetside.co.uk/index.php?topic=11333.0

I would never advise using TG's 'softness' parameter, for anything, in its current state, it just isn't worth it, as you've just found out.

[Tangled-Universe]

Thanks Martin, that's something I wasn't aware of.

[Hetzen]

Thanks for this heads up Martin. It's something I've never dipped into.

[Oshyan]

Another possibility is you need to increase the Ray Detail Multiplier. This affects the detail of reflected geometry.

- Oshyan

[Nico3333fr]

Fine, thanks for all these good advices. I've taken them into account, I'll try to re-render it asap, to see if the problem is solved.

See you and thanks again !