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RySan
02-04-2008, 01:16 AM
Hello all,

This may be a novice question, but I've been getting some rather weird looking results when rendering my bridge scene I've been working on. I'm using software rendering with depth map shadows and I keep getting some artifacts on my objects. When I mess around with bias settings, it gets rid of the artifacts, but also gets rid of the shadows, which makes my scene look flat. I'm sure this is something that has been solved somewhere on these forums, but I couldn't find it. Here's a pic. Any help would be greatly appreciated. Thanks!

Bitter
02-04-2008, 04:39 AM
What kind of light are you using and is the resolution high enough on the shadows?

RySan
02-04-2008, 12:33 PM
I'm using spotlights and the texture resolution is 1024.

MAV4d
02-04-2008, 02:34 PM
check your normals, they might be reversed?, also check your UV mapping

MAV4d
02-04-2008, 02:42 PM
check your normals, they might be reversed?, also check your UV mapping

RySan
02-04-2008, 09:04 PM
so wait, even if I'm just using a lambert shader with no texture, I still need to have the uv's sorted out for the lighting?

MAV4d
02-04-2008, 10:13 PM
it can effect it

bankievr6
02-05-2008, 01:14 AM
what are your AA samples set to?

Bitter
02-05-2008, 01:21 AM
I'm nosey, how big is the scene? It looks like big blocks of bad resolution on the Dmap. Run raytrace shadows. . .does it go away?.

acidream
02-05-2008, 02:40 AM
In my experience, I've never seen the uv layout or lack of uv layout affect lighting and shadowing. That's not to say it's not possible, maya surprises me everyday. In addition to what the others said, check to see if you have double faces on top of each other. It looks kinda like that to me.

MAV4d
02-05-2008, 05:24 AM
In my experience, I've never seen the uv layout or lack of uv layout affect lighting and shadowing. That's not to say it's not possible, maya surprises me everyday. In addition to what the others said, check to see if you have double faces on top of each other. It looks kinda like that to me.

i know i wouldnt think it would effect it either, but i was running gobos in one scene and i was lazy and didnt lay out the uv's... took me a few hrs to figure that out lol. Now its just one of those quick things i do if i have simple problems, normals first uv's second


-Mike

RySan
02-05-2008, 04:22 PM
Thanks everyone for all of your help! I'm gonna try all these things tonight, and see if it works. I'll let you know when i've figured it out, and how I fixed it. More comments are welcome, of course.

RySan
02-06-2008, 03:27 AM
Alright, so here's the deal. I tried all of your suggestions, and I ended up finding a solution. When I sized down the lights and objects, bumped up the shadow bias a tad, and increased the shadow map res., It gave me better results. The lines are not as noticable, but I'm pretty picky and it also increases the render by more than 2x. UV's don't affect the lighting, i'm not using aa samples since I'm not using mental ray, there are no double faces, the normals are fine, and raytracing makes it look too flat. So, in short, problem solved! Thank you all for your excellent feedback. It's greatly appreciated.

Here's my new result. A before and after.

Bitter
02-06-2008, 03:35 AM
Regular staircasing on flat faces is the bias issue. The shadow acne needs a tad more bias. Too much moves the shadow off the surface. If you don't take care of it, then an animation will artifact in motion. Try mental ray as well (raytrace shadows are usually faster than maps but you can save out a map.) I find fewer shadow issues with MR than Maya.

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02-06-2008, 03:35 AM
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