Flickering animation! |-(

[Junglejuz]

Hi guys.

I've been rendering a slow moving animation of an interior, using a saved irradiance map (calculated every 10 frames) and and a saved photon map. The animation is flickering really badly, especially on those objects using interpolated glossy reflections. The GI appears consistent - no problem there.

To give you an idea... I have a refridgerator with a glossy reflection and anisotropy. It looks like it is wobbling like a thin sheet of tin foil.

The is also flickering apparent on cupboard door gaps (popping on and off)

I was wondering if maybe some of you guys might know of a possible solution for these horrible effects. I am rendering only at 480x360 and each frame is already taking up to 30 mins. (700Mh Celeron admittedly).

These are my settings:

AA adaptive sampling -1 2

Irradiance map -3-2
HSph subdivs 20
Interp. samples 60

Bounces 20
max photons 30
multiplier 3.0
max density 0
store direct light

All glossies are calculated at -3 -2
Interp. Samples 20


Thanks for any advise.

regards,

JJ

[RErender]

Sounds like AA, I've been rendering my animations at 0,3 with a threshold of .05, I'm afraid it will add a bit to the rendertime...

[Junglejuz]

Sounds like AA, I've been rendering my animations at 0,3 with a threshold of .05, I'm afraid it will add a bit to the rendertime...

Yeah. The popping lines, etc could be an AA issue but the glossy reflections are rendering out inconsistently each frame. This is more than AA from what I can tell. It looks like it has something to do with the interpolated glossy sample rate. I would have thought -3-2 would be plenty for this. Is there something i havent addressed here?

[GoncaloP]

The consistence of glossi interpolations are related with the consistence of GI settings, can you show some images?

Gonçalo

[vance3d]

you will most likely need to adjust your glossy interpolation settings for color threshold and normal threshold to get rid of the flickering. like with gi light calculation, these setting have a bearing on how many samples are clustered around areas that have changes in color and normals. Try lowering these settings and see if the flickering improves.

V miller

[Dynedain]

if its an animation, turn off the interpolated glossys and use regular old subdivision

[Junglejuz]

The consistence of glossi interpolations are related with the consistence of GI settings, can you show some images?

Gonçalo

you can see the flickering in this small quicktime

http://www.junglejuz.o-f.com/anim.mov



vance3d: I have no idea really how to use these threshold values, but will give it a try.

Dynedain: Turning off interpolation would be a very last resort, in which case I'd probably dispense with glossiness altogether. I can't afford much more in the way of render time. Each frame is already taking around 30mins. If I bump up the AA sampling this will increase yet again, never mind using standard subdivs for glossiness.

[RErender]

Need a question mark to see it http://www.junglejuz.o-f.com/anim.mov? looks like all of the above

[vance3d]

If you do go down the non interpolated glossy route try some low subdivision settings and work your way up. The default is 50 but I've gotten away with settings as low as 5 on some surfaces. a good rule of thumb is the more glossy it is the more subdivisions you need.

V miller

[jujubee]

I found this info in the vray help. Not sure if it really helps or if you already knew about. It's in the QMC sampler section:

Lock to pixels - this checkbox controls VRay's quasi-random generation engine. Throughout the rendering process VRay uses small quasi-random values to produce better visual results. If the locking option is on VRay will generate values that are dependent on the pixels being rendered. In this case two renderings of one and the same frame will produce one and the same result and thus in an animation certain flickering effect will be avoided. However if you turn off the Lock to pixels option then two renderings of one and the same frame will slightly differ. In that case an animation with not enough high subdivs value will appear flickering as qmc values generated for one frame are completely different from those generated for another.

[Junglejuz]

jujubee: Thanks for the tip but those QMC settings are on by default anyway. I don't understand enough about them to go messing around with them either.

vance3d: I tried reduceing the color threshold to 0.1 on the refridgerator material. It didn't seem to make any noticable difference. Normal threshold I left as is because it is a flat surface anyway.

I'm wondering wether it's necessary to recalculate the irrmap and photon map as a result of changing these material settings. Personally I wouldnt have thought so.

Looks like I might have to resort to getting rid of interpolation, much to my frustration and disappointment.

[cocolas]

your anim link isn't working.

[Junglejuz]

This link should work:

http://www.geocities.com/jay_imhoff/anim.mov

[cocolas]

nop!! - 'page unvailable'...

[RErender]

put a ? mark after the v in mov and it works...