Animation Prepass Flickering.

[Steve_Brinca]

What's up people,

Maybe someone can help me here. I have a animation with animated people, cars, birds etc. The problem isn't with the animated objects its with the buildings. I'm getting some flickering on the walls of the buildings. I love the render times from the animation prepass method but i seem to get bad results from it. Can anyone enlighten me on the prepass method to get good renderings.

I've even sent one render at a huge at extremely high settings: Medium Animation at 200/30 and I still got flickering. I also changed the interp frames to 4 and still got flickering. I just want to know what settings I should be using or if i should be using prepass at all.

My original settings are:








Movie,Sorry for crappy re but the problem is in the red box:
http://s27.photobucket.com/albums/c1...lem8-25-08.flv

I've searched around the web but i can't find a straight answer to my problem. Maybe someone here knows how to do this. Thanks again guys.

[Morbid Angel]

one solution would be to increase the hsubdivs from 50 to 100 and see if that works.
The other would be to use a bigger frame blending range. I.e. set interpolation frames to more then 1, such as 2-3 etc..
However I think your problem may be with lightcache. Try to experiment without lightcache first and draw your conclusions from that.

[Steve_Brinca]

Morbid Angel,

THanks for the quick reply. I have done what you suggested already. I've sent a render with the hsubdivision at 200 and the interpolation at 4 frames and i still got flickering. I also tried to send the light cache at at 3000 with the hsubs 200/30 and that didn't work.Any other suggestions?

I'm trying to avoid sending different passes because this way is much faster and easier. So if i could get around this problem that would be great. Thanks again.

[Morbid Angel]

I would say at first try to calculate irradience map without lightcache, and render it without lightcache.
See if that works for you.

[Steve_Brinca]

I will try that right now and let you know the result. Thanks again.

[gadzooks]

co-planar faces? Might check too see.

[Steve_Brinca]

So i tried to render the scene using only irradiance map prepass and brute force. The renders come out clean but they take forever for a 720x480 resolution(my settings were Medium 50/20 and brute force 5/2). I even lowered the settings to Medium 30/20 and BF at 2/1 and the renders were taking well over 20 mins.

The first thing i checked was the thought of co-planer faces but there isn't any.

I've gone a different approach, I'm now rendering Brute Force as primary and Light Cache as my secondary. Its the only way i can render with any flickering what so ever and it gives me decent render times. I've read on other forums that the prepass doesn't work that well and you really have to crank the setting to get a good result. Maybe I'm doing something wrong with my settings but I've tried everything. I've tried extremely high settings(still flickering), changing the inter frames to 5(reduces the flickering but long render times), and now i have to use brute force to render this scene.

Vlado, is there any solution? Do i need to send you the scene so that you give me a definite answer?

[duke2]

I've done the same thing with my last project. Brute Force and LC secondary. What I found made a huge difference to flickering or not was Store Direct in LC. For the love of god, turn it off.

[Morbid Angel]

if you want, you can post a part of your scene which demonstrates the problem and we can take a look at it...

[Steve_Brinca]

Morbid Angel there is a link to the scene at the bottom of the original post. I will post a high rez version if need be.

Duke2 does that apply to the scene if I'm using vraysun/vraysky?

Thanks for all the help guys. I'm pulling my hair out trying to render this scene lol.

[Morbid Angel]

as far as I can tell, the link is for the video file only. I actually meant a .max file.

[duke2]

Yes it applies for sun/sky. Also try higher interp samples like 40 or 80 (rather than 20) and render the prepass with a gamma of 2.0 to affect the sample distribution so it doesnt ignore the shadows too much. This should NOT affect the final render (put it back to 1.0). And these are only suggestions, I haven't actually tried that last one.

[Steve_Brinca]

So here are the results,
I sent a render over the weekend using the BRUTE FORCE+LIGHT CACHE METHOD, the renders are taking so long, almost 3 hrs per frame! I'll try your suggestions duke2, hopefully they give me decent render times because I cant afford 3hrs+ render times for a 720x480 resolution.

[vlado]

If you wish, you can send your scene to vray@chaosgroup.com and we'll try to optimize it for you.

Best regards,
Vlado

[Steve_Brinca]

Thanks Vlado,

I'll get the scene to you guys asap. Hopefully you can tell me what I'm doing wrong. I've tried everything to get this scene flicker free. Thanks again.