How to avoid this when baking normal maps?

oddnadia

So I'm using Substance Painter to bake maps for characters but I always stumble upon this issue: when baking the high poly into the low poly there's always artifacts in the "smaller" areas such as the corners of the mouth, the nostrils, the ears, etc.

Why is the reason for this? Is there a way to avoid it and getting a cleaner bake?

pior

Well ... what's the problem ?

oddnadia

pior said:

Well ... what's the problem ?

Sorry if it wasn't clear on the picture. Here's what I meant:

There are clear artifacts in areas that are small and partially hidden. I believe they could be solved by tweaking the baking settings but I have no idea on what to do.

gnoop

It's typical ray  distance  issue.   Make it smaller   but it could create artifacts in other areas where low poly deviates  from hi poly too much. 

Workarounds : 

1.doing and tweaking manually a cage   to make it's own ray distance for evry specific vertex/place.

2.  using marmoset which  bakes in real time  and you could paint  your cage distances by  a brush.  ( painting is not very convenient)

3. making  your own setup in your 3d package with  same kind of distance painting.  I recall it worked in Modo     at  some ancient times I tried it .  Also did so in ClarisseFX.

4. having your hi and low poly sharing same UV. That way you could render object space normal map directly on hipoly , apply result on low  poly and re-bake into  tangent space  without any  hi to low  ray tracing at all.

oddnadia

gnoop said:

It's typical ray  distance  issue.   Make it smaller   but it could create artifacts in other areas where low poly deviates  from hi poly too much. 

Workarounds : 

1.doing and tweaking manually a cage   to make it's own ray distance for evry specific vertex/place.

2.  using marmoset which  bakes in real time  and you could paint  your cage distances by  a brush.  ( painting is not very convenient)

3. making  your own setup in your 3d package with  same kind of distance painting.  I recall it worked in Modo     at  some ancient times I tried it .  Also did so in ClarisseFX.

4. having your hi and low poly sharing same UV. That way you could render object space normal map directly on hipoly , apply result on low  poly and re-bake into  tangent space  without any  hi to low  ray tracing at all.

I think the fourth option is the best for my workflow. Thank you very much!

poopipe

Option 4 only works if your objects/UVs  are topologically similar - ie. anything present in the highpoly needs to be in the lowpoly 
Baking floaters or layered clothing for example would require additional setup work. 

Most people work with cages because it works and is relatively simple

gnoop

If  floaters borrow its UVs from surface they are floating over ( through uv projection )    it usually works just fine . Well, in Blender at least

Kanni3d

Can only imagine the monumental pain in the ass it would be to not only UV your high res mesh (other than simple primitive shapes) and have your lp match that closely for the object space -> tangent space conversion to work nicely. Would much rather use a cage and modify the problematic areas to be further out/closer together.

poopipe

gnoop said:

If  floaters borrow its UVs from surface they are floating over ( through uv projection )    it usually works just fine . Well, in Blender at least

its totally doable, I wouldn't ask anyone to unwrap a bunch of decimated zbrush sculpts unless I wanted to save myself the hassle of firing them though

gnoop

Kanni3d said:

Can only imagine the monumental pain in the ass it would be to not only UV your high res mesh

I actually meant  unwrapping low res    and  then detailing it / sculpting over  /   keeping original UV .     Floaters if they are one sided   and borrow uv  from surface bellow   bakes as a single surface in Blender . 

Zbruch decimate has  keep UV  option BTW

pior

The actual solution is simply to use a baking cage to finely control the ray distance (or to use the Toolbag3 distance painting tool, as it is better tool than SP for baking anyways) ; as well as modeling the mouth more open to begin with. That's it.

poopipe

Dude.. Don't let good sense get in the way of an argument over details