Hard edges on UV seams for character models?

Boozebeard

So I know that you should have hard edges across your UV seams on hard surface models for proper normal map baking but I just realised I don't know how this applies to character/organic models. I can't see why you wouldn't but I don't recall ever seeing a character model with hard edges in it.

Neox

yes it works, in many cases it is not needed but it comes down to how lowpoly your model is, if you have pretty bad shading in the lowpoly, the normalmap will have to do a lot of work to fight against it. Usually characters are highpoly enough to compensate for this. That said, there are cases with modulesystems where it should be done, so you can later remove or attach parts to you model without shading errors.

Farfarer

Generally that's something you'd do for hard-surface items.

It's beneficial when you've got quite sharp edges in the low poly mesh because it means the normal map has less "work" to do - it doesn't have to account for a rapid change in surface normal. Edges with a 90 degrees or sharper can be problematic even for properly synced normal maps. For softer shapes there's not as much of an advantage because there's not as much work for the normal map to do anyway - it's quite a regular and slow change in surface normal and it's unlikely your organic shapes will have lots of sharp edges.

For characters... I might add hard edges at "natural" seams (where clothing starts/ends for example - but only if you've got a nice loop that fits quite closely around that natural seam) or on hard-surface parts of the character (accessories, etc) but not on the smooth parts (the UV seam that runs along an arm or leg, for example, or around the head - I'd leave those smooth).

Boozebeard

Thanks guys.

Boozebeard

Why am I getting these seams along the UV borders in my normal map?

Neox

where did you bake and whats your tangentbase setting in marmo?

Boozebeard

I baked it in blender with the new cycles cage baking. Should I try xnormal?

The tangent settings are just set to marmoset.

Farfarer

I think Blender uses MikkTSpace, so try setting your tangents to that.

Boozebeard

Doesn't make any difference. Only the 3ds max setting actually looks any different and it doesn't effect the seams.

Boozebeard

Fixed it! Had to check "write normals" in the obj export options.

EarthQuake

For a mesh like this, where all the shapes are generally soft and there is enough geometry to represent the harsher angles, there isn't much benefit to setting uv borders as hard edged.

There may be some drawbacks to doing it, especially if you need to make LODs. Generally with organic shapes, you'll get more issues with seams when reducing the triangle count if you have hard edges.

As to your first question, its too vague to really answer. What is a character and why is it different from a prop? A character could be a robot comprised entirely of hard surface objects, a dwarf with sharp, metallic armor. Whether something is a character or not really has very little to do with it in reality. The important thing is the structure of the asset itself, as Steffen mentions above, the smoother the surface of the model/shading is the less need for hard edges. This migth vary between different parts of a character, again the soft fleshy bits and hard edged armor, gear, etc.