I have 'Flickering' textures and can't seem to stop them.

[RobH2]

I've read what I can find here about 'flickering' and don't see anything that addresses my problem. I have a scene that's the interior of a device. It has vinyl hoses, metal fittings and painted surfaces. My metal flickers and some of the vinyl textures flicker.

I'm using MR and A/D materials. I have several Photometric lights and only one with 'raytraced' shadows.

I've included a capture of my 'Indirect Illumination' setup. I followed the 'Help File' suggestions on reducing flickering. I've also included a short segment showing the issue here nvision4d.com/guest/FlickerProblem1.mp4

Any ideas about what causes this and how to correct it. I've never had problems with flickering. I must have something set incorrectly but can't seem to find it.

[stephengabriel]

Try the following:
1) Reset your Divide Path by number to 1 to create a single FG per frame.
2) Set the Final Gather Map in the Reuse rollout to Read FG Points Only and leave the Interpolate at 2.
3) Pre-generate your FG Maps starting two frames before your animation start and ending two frames after your animation end.
4) Render you animation reading from the stored frames. The interpolation option should smooth out the noise and has worked well for me in the past.

Stephen

[RobH2]

Stephen,

Thanks. Quick question:

1. When I Pre-generate the FG Maps I guess I do that at the same render settings...correct? That makes the final render time twice as long correct...once to Pre-render and then once for the Final Render?

2. To render from the 'stored' frames do I need to turn anything 'on' or 'off' before I run that?

[CAMedeck]

Rob, you definitely want to always generate your Final Gather map before rendering an animation. If you rendered it out with your settings, then immediately re-rendered, the two animations would be different because the FG map file is constantly changing.

If you do not have any objects or lights animated in your scene, then you can continue using the FG settings you have already. Depending on the length of animation and the distance the camera travels, you may want to increase the number of segments along your path. Ideally, you'll want every visible surface to be "seen" when generating the FG Map.

You'll want to set the FG file to Read Only. Then click the Generate Map Now button and let it calculate your Final Gather. Once it's done, send the rendering. It won't recalculate anything, just read the saved map, so it really shouldn't take any more time than it does now.

[RobH2]

Thanks Chris. This works OK but I still get flickering with any metalic texture that has a high reflectivity. I'll keep experimenting. I appreciate your comments.

[stephan_reischer]

Hi RobH2,
maybe this has nothing to do with your fg solution but with your material settings. If you are using fast interpolation for reflection then you should use this single-sample-for-enviroment thing and maybe a higher count for neighbouring-points-to-look-up. More glossy-samples will work with fast-(interpalate) sttings as well.
Hope this helps!
cheers,
Stephan

[CAMedeck]

Sorry Rob, didn't realize I hadn't suggested a solution to your problem in my previous post. The flickering, like Stephan suggests, is likely your reflections. I've found that fast interpolate and animations don't always play well together. Especially when dealing with curved surfaces and/or self-illuminated materials being visible in reflections.

Try as Stephan suggests, especially increasing the glossy samples. You may find a good combination of settings with the fast interpolate that works for you as well.

[RobH2]

Thanks guys. Great suggestions. Yea, I'm still having all kinds of crazy density fluctuations that are localized. I don't really have any textures using fast-interpolate but you point me in a good direction. Unfortunately this is a rush job and I’m about to get into trouble. I need to solve it soon. I may just rebuild all of my textures from scratch.

Thanks...

[RobH2]

I'm having some luck. I've tested your suggestions and am having good results. Thanks guys for your help. You saved my schedule and taught me some additional 'finer points' about this fantastic program we get to drive.

Best regards...