How can I Fix these Seams in my Normal Map

pixaeiro

Hello,

I'm developing a tool to generate a normal map that softens the hard edges in Low Poly models without the need of a High Poly model.

This is one example:

Everything works fine when the soft surfaces are on their own UV islands as seen above. However, when I bake a model where the soft surfaces are attached on large complex uv islands, I see seams at the edges where the surfaces meet:

Detail:

My hunch is that OpenGL is filtering the texture, and the filtered normal is very different to what would be logical at that fragment. I can fix the texture baker or the fragment shader but I've ran out of ideas to test.

Does anybody know what is wrong, or have any ideas or suggestions?

Thank you very much in advance!

ZacD

If there's a hard edge on a model, you need to split the UV map at the hard edge, or you need will get a seam. You could also get rid of the hard edge. Both options work, and they both have various pros and cons.

Neox

don't forget, if you split your uvs, move them a bit apart

if you use smooth shading, you might get intk trouble once your normalmap gets compressed

Revel

Even on your first image example, there is an inconsistent shading of light and dark on the edge that you shouldn't get if you bake from highpoly.

pixaeiro

Thank you guys! Definitely the model UV map needs to be split at the hard edges to avoid artifacts.

Revel said:

Even on your first image example, there is an inconsistent shading of light and dark on the edge that you shouldn't get if you bake from highpoly.

Yes, you are right! Somehow the model I was using had the normals facing in wrong directions. Since my tool bakes a new normal map that softens the hard edges using the existing mesh normals, the new baked normals were pointing in wrong direction too!

This is how it looks now when I generate normal maps that softens the hard edges with a radius of 0.0, 1.0 and 2.0:

Synaesthesia

This tool sounds interesting - do you plan to beta test it?

pixaeiro

Synaesthesia said:

This tool sounds interesting - do you plan to beta test it?

Absolutely, this tool is a new 3D image node for PixaFlux, which has been in beta testing for more than a year now.

The name of this node is Mesh Soften Edges and it takes as input the low poly models and bakes a new normal that softens the hard edges. This normal map can be used as the base for sculpting your normal map, or it can be mixed with other normal maps.

I'm still working on this tool but it's almost ready... This is the first test for multiple models that share the same textures:



I will do a few more tests and release a new beta version this week!

Thanks for your interest!

musashidan

This definitely looks very interesting. Always on the lookout for new workflows.

Bek

I've seen someone do this in Substance Designer too, if that is of interest to you. There's also some talk of this/similar technique being used here: http://www.gdcvault.com/play/1022324/The-Ultimate-Trim-Texturing-Techniques

musashidan

Bek said:

I've seen someone do this in Substance Designer too, if that is of interest to you.

That's right. I remember watching that vid a while back(if it's the one I think it is) and have been trying to find it since. Have you got the link?

gsokol

Sounds like a pretty nifty tool.

pixaeiro

I have just uploaded a new PixaFlux release that includes the new Mesh Smooth Normal node, which bakes a new normal map that smooths the normals and softens the hard edges.

I would really appreciate if you can give me feedback about this new node or PixaFlux in general! I'm planning to add a few more nodes and update the workflow to make it easier to sculpt normal maps.

I have also uploaded a video tutorial to YouTube:

https://youtu.be/G7-h3Teon5I

chrisevansart

Hey @musashidan @Bek here is the link to the substance designer node.
https://www.youtube.com/watch?v=2V3IRKya-AQ&t=687s

@pixaeiro This look very promising! Will def give it a try!