5
$\begingroup$

See video sample HERE

Here's another example

This has happened on multiple projects -- this was only a test project I made. When I create a fluid simulation, bake, and render it, some of the frames render out distorted (and those frames take a much longer time for Blender to render; the others work much quicker).

My question is, why is this happening? And is there a way to fix it?

UPDATE: Seems to be related to the motion blur, exclusively in the Cycles engine. When I turn motion blur off, the distortion - both geometry distortion and shading distortion - appear to be gone. When enabled, they occur.

Running Blender 2.75a x64 on Kubuntu 15.04 x64, KDE Plasma 5.3.2, and rendered with 2x Nvidia GTX 660's via Nvidia CUDA for Linux. Latest proprietary drivers used.

Thanks!

$\endgroup$
  • $\begingroup$ Good question. I see two problems occurring - one with the geometry and another with the shading. Which does your question pertain to, or is it both? Also, the first video appears to be using the Blender Internal render engine, while the second is using Cycles. I just want to confirm, are you experiencing this in both render engines? $\endgroup$ – Mentalist Sep 15 '15 at 20:30
  • $\begingroup$ Mentalist, it's both. I haven't tested this with Blender Internal; the engine I used in the samples should have been Cycles. I discovered in other forums that this is a limitation with fluid simulation and motion blur while rendering. Blender can't render a fluid simulation with motion blur, otherwise (evidently) you end up with issues like these. $\endgroup$ – Jesse Sep 18 '15 at 18:48
  • $\begingroup$ Good to know. Seems you found the answer, so why don't you go ahead an post your comment as an answer? It would help shorten the list of unanswered questions and may help others who are looking for the answer. $\endgroup$ – Mentalist Sep 21 '15 at 14:38
2
$\begingroup$

I discovered in other forums that this is a limitation with the fluid simulation and motion blur effect while rendering. Blender can't render a fluid simulation with motion blur, otherwise you end up with issues like these. Disabling motion blur will result in fluid rendering fine.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.