Black edges after baking normal map

Cirmius

Hi!

I see this is some kind of a common mistake, but I couldn't find satisfying solution for it.

This is what happens to me at some edges after baking a normal map. I heard that beveling that edge before baking can help, but it has seam so after all it only complicates things.

Eric Chadwick

What baker, and what are you using to render? Can you give some context... how small or large is this detail? What does the lowpoly wireframe look like, and what does the highpoly look like? Are you using edge padding? Did you see the Sticky topics in this section?

Cirmius

Every time before I post a thread I check half of an internet, including this forum and as I said in other words: the solutions didn't work for me. I use edge padding.

Eevee/Cycles, the problem appears no matter of rendering engine.

I forgot to mention the software and actually it's probably important thing here, sorry. This problem happens only when I'm using Marmoset. I also baked normal map using xNormal BUT with low edge padding and this problem doesn't happen here, but I don't like the effect.

Marmoset (with low edge padding nothing changes):

xNormal: (but with correct edge padding its the same as above)

how xNormal map looks like:

how Marmoset normal map looks like:

Lowpoly wireframe on highpoly:

Kanni3d

That artifacting is just a discrepancy of your low and high res meshes. Your low-res is too low of a resolution of your high-res mesh, so just add more geo. You'll also benefit from having your uv's straightened and aligned to the pixel grid in your UV's so you don't get jagged results/aliasing.

Cirmius

Thanks for the answer!

I'm always afraid of adding additional geometry (I don't know which number of quads, edge loops etc is the best for "game ready"), especially when this shown object is actually small (its just a single part of the sword). I managed with the problem by using paint skew on the edges. Looks kinda squarely, but I guess there are no better solutions.

Can I just ask you for the article/thread about how low many geometry should low poly mesh have (in game industry)? I couldn't find anything really...

sacboi

A ton of info in the stickies:

https://polycount.com/discussion/81154/understanding-averaged-normals-and-ray-projection-who-put-waviness-in-my-normal-map/p1

https://polycount.com/discussion/147227/skew-you-buddy-making-sense-of-skewed-normal-map-details/p1

Kanni3d

Ask yourself: does the allotted geometry you gave to that part of the mesh make the asset look faceted, and/or have bake errors (like above)? Then add more geometry. 

The only time when the amount of geometry is a problem is when it doesn't affect silhouette and is just sitting there. Or, more importantly, is an issue in regards of size/scale of said element with respect to the rest of the model. e.g. having a 64 sided bolt that is only an inch in diameter on a prop that is 20-30 inches wide or something. The 'density' of your geometry should always be put into consideration.

poopipe

The main thing to keep in mind is how close the camera is going to get.  An artefact is only an artefact if you can see it