Foilage Flickering in Camera Sequence

Neavah

I'm having issues with foliage flickering/sparking in my camera sequences (it's fine in still shots). I have a lot of foliage (grass, leaves, plants etc. using alot of alphas) and the sequence looks like shit.

My thoughts were that this was mip map related.
(My knowledge of mip mapping is limited to what is on the pc wiki.}
So I changed LOD Bais (try everything from -2. to 2) and no change. I fucked around with the LOD Group, that didn't seem to do much either. Also tried changing the mip gen settings (I didn't create custom mips).
Perhaps there's something I'm missing?

My next though was it was alias related.
I enabled DX10, and changed the maxmultisamples to 4 (I'm running xp, I read DX10 doesn't work with xp... but wishful thinking I guess) that didn't help either.

All of my textures are pretty well padded... green leaves have green bg etc.

When I watched youtube vids of other udk scenes, I don't see this flickering/sparking. So I image this is something noobish that I'm just missing. That and I can't find anyone with this exact issue through google....

Dose anyone have any idea how to minimize/fix this issue?
Is there something I can do to postprocess to help minimize this?
Is there a step that I'm not aware of...?

Perhaps this has already been covered somewhere and I'm just using the wrong terminology in my searches?

I apprecaite any insight!

Aleia

If I understand what you're describing correctly, I have the exact same problem.

Isn't there anyone who knows what it might be? Theories, ideas, anything?

teaandcigarettes

Could you show an example of the problem? It's difficult for me to tell what the problem is.

If it's just the regular aliasing problem then it will always be there as long as you use Blend_Masked, blend mode. You can reduce it by enabling FXAA, but the result will be a little bit blurry. You can go with Blend_SoftMasked to reduce it, but it will be more expensive.

DX11 has antialiasing for masked materials but I haven't had the time to look into this yet.

Adam L. Gray

Yes, I had this problem as well, and it's a real bummer. The only fix I found for it, is to disable '2-sided' in the material, and then manually add a backface to the model itself.

Other than that I found no info on the subject. It's almost as if the material adds a backside to the material, being un-illuminated, and showing up in a shade of black (like you would normally see in 3ds max when you don't have backface culling enabled)

At the same time, it copies and inverts the mesh, giving you a correctly lit backside of the plane, or whatever you're now using. Which in turn is z-fighting with the unlit backside.



It just sounds completely bonkers, and I don't see why one would possibly want to do anything like it. But it's the only explanation I've managed to find so far. So, to me it seems as if it's some sort of bug, occasionally appearing, depending on whatever variables.

Cheers

Aleia

Thanks for the replies! It sounds more like the problem Adam's describing, which is a bummer, because there's not really a lot I can do to fix that :S. But I can change the blending mode to SoftMasked and see if that helps... if not, I'll get back to you with a video so you can see what it looks like. Probably easier to help then!

Aleia

Well the SoftMasked blending mode unfortunately didn't help, so I've render out the video I made now so you can take a look at the flickering. Unfortunately the compression kind of makes it difficult to tell what it really looks like... but basically it's mostly the edges of the leaves in the trees and on the ground that have it. It seems like the further away they are the more they flicker.

http://vimeo.com/34948550