Post Apoc Gunner

CheeseOnToast

Please excuse the crappy presentation, just a quick screen grab from Melody just now 'til I get the problems sorted out.
Did this as a first serious attempt at high poly stuff and normal mapping. I've still got a few tweaks to make to the low-poly version to iron out some of the problems, but there is one thing that's got me stuck. The normal map on the earphone things turns out with a fluted, wavy edge rather than a smooth border. The low poly version obviously has a reduced number of sides on the cylinder, and this seem to be the cause of the problem. Anyone know a way round this? I've tried UVing it several different ways, and also letting Melody layout the UVs. Nothing I've done makes any difference.

vahl

first off, nice model

about the normal map distortion, you can't really avoid it (or at least I haven't found the way to do it yet) automatically.
What I usually do is paint over the normal maps in photoshop to fix distortions (the nvidia normal map filter is very useful for this).

MoP

Looks good so far, keep it up

Not quite sure what's going on with the chin-strap on the hat, looks like it's just glued onto the side there... maybe a little button or rivet holding it on would look better?

As for the distortion on the normal-map there, it's actually got nothing to do with how you lay out the UV-maps, really ... that is a result of the projection cage (where the rays are cast outside the lowpoly model from) ... the "tighter" the cage fits around the lowpoly area without letting any of the highpoly mesh clip through the cage, the less distortion you're gonna get. I know you can tweak this in 3dsmax7 with the Projection modifier, but i don't know about Melody. Try changing the ray-cast distance to a lower number if that's possible.

MoP

notman

I'm thinking he was going to show stitching for the chin strap when he does the texture, rather than a modeled rivet. Just my guess though

Oh, and I also like the model

saturnfive

[ QUOTE ]
The normal map on the earphone things turns out with a fluted, wavy edge rather than a smooth border. The low poly version obviously has a reduced number of sides on the cylinder, and this seem to be the cause of the problem. Anyone know a way round this? I've tried UVing it several different ways, and also letting Melody layout the UVs. Nothing I've done makes any difference.


[/ QUOTE ]

Tweaking the ray cast distance will probably make no difference. This scalloping happens because the cast rays are interpolated across the vertex normals at the ends of each face. So geometry at the end of low poly faces will tend to 'scallop' where it reads some distance between the high and low poly faces.

There are two ways around this problem: 1) make your high and low poly the same number of faces, so there's no difference to show up, or 2) Detach the cylinder faces and render them out as a seperate object, then composite them onto one map afterwards.

Nice model btw.

poopinmymouth

What saturn said, best way I have found in this situation is to separate the ears to a different smoothing group, then the normals will cast out radially instead of with scalloped pattern. The other option is to hand edit the normals on the low poly to face differently. It's a lot of hard work but can be made to work.

JKMakowka

Didn't tpe post a way to avoid these normalmap errors on the old boards? Can't remember exactly what he did, but it was a similar problem.

MoP

Yeah, he modelled stuff separately as a perfect cylinder, even if it was destined to be a different shape, then normal-mapped that, and just altered the lowpoly mesh to the correct shape afterwards. Sensible.
However I agree with what saturn5 and poopinmymouth say here, too. Either method will work.