v-ray opacity map flickering in animation

[loklomedia]

I posted this in CGtalk, but will duplicate here for maybe more specialized answers.

(sorry for the duplicate/repost...)

 

So I'm brand new to v-ray (2.10) - just installed it 6 days ago, and converted and completed a scene with it, having used MR most recently, and Brazil in the past.

I'm in a bit of a hurry, deadline-wise, and don't know the quickest route to solve this problem.

The GI is fairly stable, in fact using only Irradiance Map with:

- Medium-animation preset,

- Hsph. Subdivs = 30

- Interp. Samples = 20,

- Least squares Fit/Density Based

 

Using Adaptive DMC/Mitchell-Netravali with 1/3 subdivs, and using Clr Thresh = 0.02 oversampling/rendering at 540 tall, with final desired output = 480 tall.

Using standard vrayhdri environment map for the sky (builtin, not my own image), vray sun, vray physical cam; linear multiply color mapping, and levels clamped to 1.0.

 

Max Tree Depth = 55, min leaf size 0.005m

 

Being rendered on a mini farm with all intel Quads, though different CPUs (2xq6600, 1xq9550, 1xi7).

 

Some of the trees are geometry with alpha mapped leaves, some are planars/billboards, though it looks like it's the geometry shrubs and trees which are flickering the worst.

download a 3 second MP4:

http://loklomedia.com/files/vrayflickering.zip (~1MB)

Any help is appreciated - I've gone through most of the up front tutorials I could find (free), and have a fairly good feel (generally) for the settings, but not enough to troubleshoot specific issues.

Thanks in advance!!

[rafa rubio]

same problem here.... found something??

cheers!

[Corey Beaulieu]

How are you rendering it? Irr on Multiframe incremental pre-calculated and Light Cache on Fly through on a single machine? or are you just sending it on single frame to an entire farm?

 

Also, you could up your IRR min/ax to like 50/25 or even 60/30. I've also had some success with pre-calc-ing the Irr at half resolution.

 

In the end if your deadline it coming at you too quick to really spend the time discovering the solution, try Brute force with 12-16 subdiv Light Cache on single frame and 800-1200 subdiv. If you un-tick the time indepence box any noise will be like film grain.

 

good luck and I hope this helps a little. There are a lot of variables.

[Ricardo Eloy]

Doesn't look like a GI problem. Your Image Sampler values are too for an animation like this, with all the little leaves and all. Try 2/6 at 0.005 for the DMC and do not use Mitchell (it will likely increase the problem). Try VRayLanczos instead.

[rafa rubio]

How are you rendering it? Irr on Multiframe incremental pre-calculated and Light Cache on Fly through on a single machine? or are you just sending it on single frame to an entire farm?

 

Also, you could up your IRR min/ax to like 50/25 or even 60/30. I've also had some success with pre-calc-ing the Irr at half resolution.

 

In the end if your deadline it coming at you too quick to really spend the time discovering the solution, try Brute force with 12-16 subdiv Light Cache on single frame and 800-1200 subdiv. If you un-tick the time indepence box any noise will be like film grain.

 

good luck and I hope this helps a little. There are a lot of variables.

 

irr on multiframe incremental pre calculated an light cache on fly .... rendering in a little render farm (32 cores)

using that crap of mitchell netravalli....

 

i think there is the problem here.... the filter... i have already renderer 130 frames.. and each took like 8 - 9 minutes to be done...

missing something??

some trees from onyx another ones from ever....

 

Any suggestion in post to avoid this problem?

 

This is the first shoot... there still be 3 more... like this one... aereal... full of trees moving camera... cars has to be rendered with other method.. (animation perepass) etc...

 

heres the link FLV format

http://dl.dropbox.com/u/10030111/CAM_PIEL_01.flv

[loklomedia]

Sorry... can't help. I gave up on vray. waste of time and money for me.

[Scott Schroeder]

Make sure your filtering is turned off on all your opacity maps. This is the filtering in the material, not the render settings. You know, pyramidal, summed area, etc. Turn that off for your opacity map and it'll speed up your renders a tad.

 

Often with trees in the distance, using brute force is the only way around the flickering. You'd only want your trees on, and comp them into the final scene. There's just too much detail packed into such a small area.

 

Another work around is you can also use proper Z-depth passes and just have those trees blurred in the Z-depth. Nothing is always 100% in focus in any film. Blur the background trees a little and you won't see as much flickering.

 

Yet another work around is to render your trees in a front shot, and create simple card trees for your far background trees. Because think about it in a sense of scene optimization. A tree that far away from the camera, does it really have to be full blown geometry? Can you even tell the difference? Just render these card trees on a separate pass using scanline, and comp them into the final scene.

 

Or you could just give up. Yeah, no point in actually learning the software. Vray is supposed to make pretty renders on it's own. If you didn't find the make pretty image button, you didn't read the manual hard enough.

[rafa rubio]

Make sure your filtering is turned off on all your opacity maps. This is the filtering in the material, not the render settings. You know, pyramidal, summed area, etc. Turn that off for your opacity map and it'll speed up your renders a tad.

 

Another work around is you can also use proper Z-depth passes and just have those trees blurred in the Z-depth. Nothing is always 100% in focus in any film. Blur the background trees a little and you won't see as much flickering.

 

Or you could just give up. Yeah, no point in actually learning the software. Vray is supposed to make pretty renders on it's own. If you didn't find the make pretty image button, you didn't read the manual hard enough.

 

Scott!

I´ll chek that maps.... about tree cards.. is not working for me because there are some cameras arround the scene...

 

Zdepth i think ist going to be the best way for it... and about the "pretty image button" jejeje.. we need it! jejeje... maybe vray 4.0 =)

 

about render times.. is it normal they took about 8 - 9 minutes each? what you think.?

 

thanks for your comments!...

 

rafa

[oligophant]

Render times vary from scene to scene and GI precalc methods ( animation prepass, save incremental), but 5 min for a 640x480 with not so much glossy reflections all over the place it is right for me, so in your case its good enough. Did you try to increase the hsph subdivs, i found that 50/20 give a lot of gi noise so 120/20 works for me ( on stills) , not tested yet on animations.