Noise on Forest trees animation

[thieuma]

Hello,

First, sorry cause I'm sure my question have already answered somewhere, I did not find. Don't hesitate to link if you know

I have a problem with the render of a moving camera scene on Forest pack low-poly trees for a background.
There is just a VraySun, no GI, no light exept the sun. The animation is a slow right-left traveling of a VrayCam, without DoF and no motion blur. The problem is a massive noise I can't suppress on the trees, visible when I play the rendered sequence. I thank it was a AA problem but the problem is the same when I strongly increase the max subdiv, even with a fixed sampler, even with a 0,001 noise threshold.

How can I can I correct this to avoid the noise ?

Thanks in advance...

[vlado]

What are your AA setting? Sometimes enabling moblur helps to smooth thing out. Using a blurrier AA filter might also be helpful.

Best regards,
Vlado

[thieuma]

Thank you Vlado. I tried a lot of things...
Adaptative sampler : min 1 / max 12 to min 2 / max 24 (!!)
Fixed : 3 to 16 but the noise was stronger with this method.

I'm not sure motion blur could change the result cause the cam movement is very very slow, close motionless.

[thieuma]

And the problem is the same with any scatter tool for the grass. Any ideas ?

[vlado]

Well, if you can post a simple scene or send me one to vlado@chaosgroup.com I can try to see what are the options.

Best regards,
Vlado

[thieuma]

Thank you again. Here is my scene, maybe i missed something obvious... BBmaq_vlado.zip
There is a example of the problem. flickering.zip
Thanks in advance !!

[Deflaminis]

Kinda looks like z-fighting. Any chance there is a copy of each tree under itself?

If not, then the "Secondary Rays Bias" may be the answer in your global switches. In this page here, both examples look similar to your problem. (Thing is you said no GI, so maybe not...)
http://docs.chaosgroup.com/display/V...obal+Switches#

[Svetlozar Draganov]

Thank you again. Here is my scene, maybe i missed something obvious... [ATTACH]23554[/ATTACH]
There is a example of the problem. [ATTACH]23555[/ATTACH]
Thanks in advance !!

Would it be possible to collapse the plugin-information to a standard 3DSMax geometries/textures etc?
We do not have a license for GrowFX and GrowFX Multimap and the scene crashes at startup with the demo versions of those plugins.
If you could simplify the scene to not use any plugins except ForestPack that would be great otherwise we have to contact Exlevel for temporary license for their products in order to proceed with the investigation.
Some of the textures are also missing - please send us that information also:


Let us also know the exact versions of V-Ray/3DSmax/ForestPack/GrowFX/GrowFX Multimap.
We are looking forward to hearing from you.

[TJE]

Was there a solution to thieuma's query?

I'm having the same issue, although not using any plugins. I'm rendering a lot of trees from a birdview position, and all the trees flicker crazily with noise. All trees are instanced. The problem persist even if I turn off GI.

I have about 1800 frames to render asap, so would highly appreciate some advice ...

Cheers!

[Rens]

You could try disabling spec and or refl on the tree material.

[Morne]

+1 What Rens said. Also, your min AA should NOT be 1, try 2 or 3.

[TJE]

Thanks for the tips, guys!

We tried everything, but the problem persist. Conclusion: it's not AA, as we've tries insane settings on that. It's not GI, as we've tried rendering without. It's not reflections, as we've tried without. It seems to happens when there's an obscene amount of small triangles seen from afar.

Vlado would be the one to know, but my theory is that the problem occurs when the faces to render are smaller than a pixel, and overlapping other triangles equally small (leaves) When the camera gets closer, the problem goes away.

Cheers!

[Morbid Angel]

where did those trees come from? they look like paintfx trees to me, are they?

[Svetlozar Draganov]

Thanks for the tips, guys!

We tried everything, but the problem persist. Conclusion: it's not AA, as we've tries insane settings on that. It's not GI, as we've tried rendering without. It's not reflections, as we've tried without. It seems to happens when there's an obscene amount of small triangles seen from afar.

Vlado would be the one to know, but my theory is that the problem occurs when the faces to render are smaller than a pixel, and overlapping other triangles equally small (leaves) When the camera gets closer, the problem goes away.

Cheers!

Can you show us an image or a video which will help to understand the issue better.
If you add all render elements in which ones you are able to see the artifacts?
Secondary Rays bias usually resolves overlapping issues - have you tried a value different than 0?

[joconnell]

I'd have a look in your render elements - render a sequence with each element as a sequence and see can you identify it in the diffuse filter, the lighting, the gi, the spec or the reflection pass. If there's flicker in your diffuse filter pass then it's aa, if there's flicker in your lighting it could again be aa or light sampling - I'd use some light select elements with individual lights picked too to chase down further.

Which AA filter are you using too? Are you planning to add motion blur in the render or in post?