View Full Version : flicker in reflection

10-17-2005, 03:13 PM

I am renering a scene with lots of small reflective objects (alot)... they flicker like hell...
How can i solve this???

does ray & reflection depth have any influence here?
antialiasing is set to still image / treshold 10% / 1x1 4x4 / MIp scale 50%

Thanks in advance.

10-17-2005, 03:25 PM
Can you post an movie clip or an image?

10-17-2005, 03:29 PM
use a compositing tag to force up the AA to 2x2,4x4. or even higher if required.

10-17-2005, 03:33 PM
Thanks strat! i'll try that...
Sorry Fred can't post shots of this project :sad: thanks anyway!

10-17-2005, 03:38 PM
Thanks strat! i'll try that...
Sorry Fred can't post shots of this project :sad: thanks anyway!

yup, altho the render time will slow down. thats why i suggest a render tag as it stays locally. also as an alternative, you might want to try keeping 1x1/4x4 and lowering the threashold .

AA can be achieved in numerous manners. it might be worth faffing about a bit with the settings until you find a solution that best suits your model/render times.

10-17-2005, 03:43 PM
i am not going to use the render tag cause all objects are reflective so i just changed it in the render settings... i'll try the next render with lowering the threashold.

Thanks again!

10-17-2005, 03:47 PM
Another option is to double the output res and then scale back down. The project I am currently working on I am doing this. It is signifcantly faster to render this way then to up the AA.

10-17-2005, 06:32 PM
just did some different settings tests...
_I raised the AA to min: 4x4 max: 16x16 treshold: 5%
bit better result but still flicker
_Instead of "still image" i used "animation"
to blurry not crisp anymore
_Scene Motion blur
insane render times

So i am going to try to render at double res. hoope this will do it...

pfff, one day of flicker solving ;)

10-18-2005, 10:23 AM
still flicker even at double resolution... hmmm :banghead:

10-18-2005, 11:04 AM
Whats actually flickering? If you have loads of reflections - reflecting each other, could it be a ray depth problem?


10-18-2005, 11:15 AM
that could be... ray depth is i set to 10 now.
The animation is like a bunch of mirrors (planes as spheres).. all object are high reflective.

maybe lowering the ray depth... i'll give it a try...


10-18-2005, 11:31 AM
but the ray depth control wont actually control the AA.

also, just thinking, when you say 'flicker' do you mean the AA is poor and flickering, or do you mean the reflections seam to be flickering on and off, ie, dissappearing and re-appearing?

if this is the case then bump up that ray depth.

10-18-2005, 11:38 AM
Yes indeed i don't think it is the AA that is flickering but the reflection, especially the bunch of small objects that reflect on the big planes... ok thanks... up to raising ray depth...

10-19-2005, 08:13 PM
Maybe this gives a better insight, here's an example, same situation... flicker in refraction & relection...


10-19-2005, 08:22 PM
Try adding Fresnel to the reflection, and maybe removing it from the refraction.

10-20-2005, 07:37 AM
Stupid question....but do the reflections also flicker when the camera is still? Just find a spot and lock the cam and render 10 frames and see if it flickers then.

Just curious...

10-20-2005, 07:41 AM
ah, i can see it now!

that looks pure and simple an AA problem. i'd add separate render tags to those glass tubes. i know you said there's no point, but localising render tags really does help with general render speeds.

then in those tags, turn the AA down a tad maybe, and play with upping the min value to 8x8 or higher maybe.

do you have a texture map in the reflection slot? if you do, you might also want to slightly SAT blur it a couple of nitches.

make sure your bump map isnt active.

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