Shadow Flickering with Vray

[beebop]

No one knows hows to eliminate the flickering of shadows using vray?

[mister3d]

It's better to use vray shadows in vray, I don't know what you are using. Try this http://gnomonology.com/tutorial/62 .Sorry, tried explaining it, but it's too long-winded. But the concept is quite simple. You need more samples either in the lightsource shadow parameters or globally but also your image sampler must have a proper treshold to eliminate the noise. :surprised

[beebop]

I'm using 2 target directional lights with vray shadows. And thanks i'll look into that tutorial.

[beebop]

I watched the tutorial and it didn't really give me the answer I was looking for. So I uploaded a rendering of it on my website for people to view. The flickering is mostly on the ceiling and walls where there's no image based texture.

http://3dimensionalartist.com/HollyWoodHouse.mov

Thanks

[mister3d]

I watched the tutorial and it didn't really give me the answer I was looking for. So I uploaded a rendering of it on my website for people to view. The flickering is mostly on the ceiling and walls where there's no image based texture.

http://3dimensionalartist.com/HollyWoodHouse.mov

Thanks

It's not your shadow flickers. When you encounter a problem, start isolating elements to see where the problem occurs. I usually add passes like raw gi, shadow so I can see where the problem is in passes. It is you irradiance map flickers now. For a better explanation try this: http://thegnomonworkshop.com/dvds/cni01.html If you have a fly-through animation without changing lights position and objects, you can use baked-in irradiance map+lightcache, so it is not animates and therefore notflickers. Your irradiance map must be set to incremental mode, now it calculates for every frame but the quality is not sufficient to give you a smooth result.
Here is how you can use the passes to see where the problem is:
http://img144.imageshack.us/img144/7417/passesze6.jpg (http://imageshack.us)
http://img144.imageshack.us/img144/7417/passesze6.21f7e3e083.jpg (http://g.imageshack.us/g.php?h=144&i=passesze6.jpg)

Go to render scene - render elements, then add - add raw shadow, raw gi(global illumination), diffuse filter(textures), raw reflection and specular. Then in your vrayframebuffer after renfering you can select the elements to view separately. The shadow pass is inverted, so don't worry why it is looks strange.

[beebop]

I did a pre-pass saving the irridiance maps and then did a rendering pass using the maps and it turned out fairly good. Some random flickers on a comple objects witch is weird, but overall not too bad. You can view it here... http://3dimensionalartist.com/HollyWoodHouse.mov

mister3d, i'm now trying what you told me to do, so i'll post back as soon as it's done rendering.

Thanks

[mister3d]

There's still some flicker, it may be lightcache has not enough subdividions. For this resolution you can try 600-800. Those are resolution-dependent. The more the resolution, the more you need subdivisions for lightcache. Or maybe it is bad compression of movie, but I doubt it. And use all vray materials with vray, no standard.

[beebop]

I finally got to render out all those layers you suggested for me. I'm not quite sure what i'm looking for though.

[mister3d]

You are looking for a problem. If your raw GI pass contains splotchiness you know where it is.

[beebop]

Oh ok, yeah there is a little splotchiness. So to solve that, turn up the passes, or what do you suggest.

Thanks

[mister3d]

Oh ok, yeah there is a little splotchiness. So to solve that, turn up the passes, or what do you suggest.

Thanks

No, it's just to see where the problem occurs - in shadows or in GI. Now work on irradiance map quality and bake it in.

[DrachenVFX]

disregard post

[netsu]

not sure if this whole flickering thing got sorted out but i just wanted to throw something in there. i have been working on something with vray as well, ligthing the scene entirley with an hdr image. for about three days i worked on how to fix my flickering shadow problem and what i discovered is that the only way i could get rid of the flicker was to pretty much use higher parameters and render the animation as if it were one frame at a time. by this i mean setting my IR to single frame and my light cache to single frame and raising my light cache samples to 1000 at least. that being said it will take a longer time to render but at least i didnt have to render it again for the hundredth time only to find it looking nasty again. this might not be the answer you were looking for but it is a solution none the less. also just a little side note. vray seems to be something that looks great in renders but if you want to render an animation you had better have a render farm. without it you'd look like old snake by the time an animation finishes.

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