Normal map..."bleeding"?

Dismembered · Jun 2011

So my normal map appears to be bleeding from one face to another.

-The numbers represent different smoothing groups, the UVs are separated at the different smoothing groups.

-I used max to bake the normal map.

Anyone know why this happens and how to fix it?

Thanks

GeeDave · Jun 2011

Normal maps V smoothing groups. It's hard to tell what the actual issue is here without seeing your unwrap, normal map and desired end result. But remember that a normal map depicts the normals of a mesh, which basically makes smoothing groups redundant in most cases.

Are you baking the smoothing groups to be used as normals? Is there a high poly mesh at play here?

Also, separating UV's by SG isn't essential (probably not even recommended) when it comes to baking a normal map. Unique shells/islands tend to result in obvious normal-map seams around the edges. Not the problem you're encountering, for sure... but a thought to hold regardless.

More details please!

EarthQuake · Jun 2011

GeeDave wrote: »

Also, separating UV's by SG isn't essential (probably not even recommended) when it comes to baking a normal map. Unique shells/islands tend to result in obvious normal-map seams around the edges.

There are no disadvantages to breaking up smoothing groups at uv islands, only a poorly set up bake would cause seams in this case. Your verts are already split at uv boarders, so splitting up the smoothing groups/using hard edges on uv borders makes no difference when it comes to performance.

Also, whats with the weird text color?

Dismembered · Jun 2011

I guess it is kinda hard to see what I am talking about without looking at the model itself. So I will try to explain it the best I can. The areas that I am pointing out seem to have the normal's from the adjacent surface overwriting their own.

I am baking this down from a high poly.

GeeDave · Jun 2011

EarthQuake wrote: »

There are no disadvantages to breaking up smoothing groups at uv islands, only a poorly set up bake would cause seams in this case.

Or, poor SG placement... surely? You're right though, especially in this example. As for the text... is orange weird? I do it on every forum that offers me a dark background.

@Dismembered, if you're working with a high poly mesh... forget smoothing groups... well, have one smoothing group for the LoPo. The high mesh should depict the direction of the normals. If it doesn't... then it sounds like your projection cage could do with some loving.

Dismembered · Jun 2011

Here is another example, maybe this picture is a little clearer?

EarthQuake · Jun 2011

GeeDave wrote: »

Or, poor SG placement... surely? You're right though, especially in this example. As for the text... is orange weird? I do it on every forum that offers me a dark background.

@Dismembered, if you're working with a high poly mesh... forget smoothing groups... well, have one smoothing group for the LoPo. The high mesh should depict the direction of the normals. If it doesn't... then it sounds like your projection cage could do with some loving.

Yeah, poorly set up smoothing groups/hard edges. ie: where you do not have a uv seam, will also cause seam artifacts.

RE: orange text, generally colored text is frowned upon here, its just annoying really.

EarthQuake · Jun 2011

Dismembered wrote: »

Here is another example, maybe this picture is a little clearer?

This is likely a case of:

A. Your low not matching up well enough to your high - http://www.polycount.com/forum/showpost.php?p=1375489&postcount=126
or
B. Your cage projecting at such an angle that your map is getting traced up the side, cutting some supporting geometry here will help - http://www.polycount.com/forum/showthread.php?t=81154
or
C. Both. =P

Something like this may fix it:

Side note, why does that tiny cylinder have so many sides?!?!

Dismembered · Jun 2011

I am trying a fix of my own real quick then I will get to yours.

B. You mean cut it in on the LP for the bake then remove it after? (Little confused on what you meant)

Your side note, mainly because this bake is really getting to me and I want to get it right. I will fix it though. Should be easy enough.

EarthQuake · Jun 2011

No, never remove geometry after a bake unless you really understand what you're doing. Editing your mesh = changing vertex normals = creating smoothing errors. Any time you change your mesh, you should rebake(unless the vertex normals stay exactly the same).

Using supporting geometry to fix normal projection issues is common, and something you should plan on, if you have XXX triangle budget, always allow 10-20% for corrective geometry.

Dismembered · Jun 2011

Hmm the support Geo did get rid of a lot of it. But it is still bleeding, any other possibilities or should I keep messing with it?

EarthQuake · Jun 2011

Post more images of your problem areas?

Dismembered · Jun 2011

I didn't save it when I added the support edges, that is why they aren't in this SS, but this is the normal map that it generated with the support edges.

cw · Jun 2011

Baking with mental ray? tried scanline? Otherwise bake double res and reduce in PS.

Those artifacts look like a combination of an aliased normal map and slightly wonky cage/low poly..

good luck!

Normal map..."bleeding"?

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