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View Full Version : Normal seams only visable from certain distance and angles?


Stradigos
08-31-2011, 11:51 AM
Well this is a new one, for me at least. The seams aren't visible from all angles or all distances. In fact, the closer the camera, the better it gets to the point of not even being able to tell. Is this a rendering issue or a serious normal map issue? I'm using four 4096 textures (diffuse, normal, spec) for head, arms, chest, legs. Attached you'll find example images and images of the head and chest normals.

The normals were exported from zBrush and are being used in tangent space. If I were to take an educated guess, are there then two normals along that seam? One for both uv shells? I think that may be the case after reading the wiki on normals some more. I can imagine that the seam is only visible when neither of the normals are shooting light into the camera when it's at certain angles.

There's a small tutorial in the wiki on offsetting the seam to a place that is a perpendicular on the mesh to hid the seam, but I don't see how that could work on this model seeing as it's not a flat surface.

At least using multiple shells fixed the crappy texture resolution I had when I was using one big one. I've just never worked with multiple UV shell like this :(

Ace-Angel
08-31-2011, 12:09 PM
Not enough padding, you need 8+ pixels. If you have your normals (baked ones) on a different channel, just install xNormal and it will install a filter for Photoshop.

It's called dilate, use that to 'pad' your bakes.

Or set it directly from ZB.

EarthQuake
08-31-2011, 12:10 PM
You need padding on both your normals and diffuse(and all other maps, spec etc).

It looks like the black background from your diffuse is bleeding through.

sprunghunt
08-31-2011, 12:35 PM
It looks like the black background from your diffuse is bleeding through.

Even with enough padding it's always a bad idea to have a black background when your predominant colour isn't black.

EarthQuake
08-31-2011, 12:49 PM
Even with enough padding it's always a bad idea to have a black background when your predominant colour isn't black.

Right, a neutral BG color is best, something that is roughly an average of the most prominent colors in your texture.

Stradigos
08-31-2011, 01:03 PM
Oi! Great advice guys, thanks. Good tips all around! :)

r_fletch_r
08-31-2011, 01:05 PM
Even with enough padding it's always a bad idea to have a black background when your predominant colour isn't black.
or fill the unused areas with padding.

Swizzle
08-31-2011, 05:08 PM
The xNormal Dilation filter for Photoshop is extremely useful for edge padding.