Stair-stepping on baked cut on corners? Even with skewing function.

guitarguy00 · Nov 2019

I tried baking a cut detail from a high poly source onto the low poly and around the corner of the object I got this stair-stepping effect when I tried to fix the skewing through Toolbags Skew feature.

Image: https://us.v-cdn.net/5021068/uploads/editor/1c/u8xul0cyxrg5.png

This is the geometry:

Image: https://us.v-cdn.net/5021068/uploads/editor/ho/bowgz2xhnzst.png

Now I am thinking that the vertical edges are messing up the vertex normals? I managed to solve most (80%)of the problem by manually adding edges following the cut detail:

Image: https://us.v-cdn.net/5021068/uploads/editor/rf/ibwitv8kds5h.png

Why does this happen? Shouldn't Toolbag's Skew function solve this or is it because it is on a corner? Is there anything further I can do to completely resolve the problem? Thanks heaps in advance.

rollin · Nov 2019

Maybe a different triangulation between bake and view?

guitarguy00 · Nov 2019

rollin said:

Maybe a different triangulation between bake and view?

Unfortunately not, I just tried with a fully triangulated mesh just now, same problem

Obscura · Nov 2019

Is the error on the skew one disturbingly visible from reasonable view distance?

guitarguy00 · Nov 2019

Obscura said:

Is the error on the skew one disturbingly visible from reasonable view distance?

Not really. However I just discovered this...

Image: https://us.v-cdn.net/5021068/uploads/editor/3x/qmti50g4qts8.png

This should definitely not be happening. I am thinking it is my hardware settings now?

Obscura · Nov 2019

Ok thats weird

I think if you post the fbxes, someone will be glad to help figuring this out.

guitarguy00 · Nov 2019

Tried baking on a laptop I used to use prior to building a PC and had the same issue. So I think I can rule out hardware and Toolbag settings. Any other ideas? I will upload the FBX's tonight.

rollin · Nov 2019

So the normalmap looks totally .. normal?

If so I would check out the low + normal here myself

Taylor Brown · Nov 2019

What does the flat 2D normal map look like?

poopipe · Nov 2019

Assuming it's not tria gulation related (which it looks like it is)....
It looks like crap precision in the uv interpolation.
It'll happen more with long thin faces, if uvs are far from the origin, things are massive/tiny etc.

Why its happening in toolbag is a mystery to me though. I can't see a single asset of reasonable size provoking floating point errors.

huffer · Nov 2019

Did you use a super heavy brush setting for painting over the skew? That happens sometimes, try a softer brush? The best option is to add a loop right in the middle of that and remove it after bake (assuming you have hard edges and the mesh shading doesn't change)

guitarguy00 · Nov 2019

huffer said:

Did you use a super heavy brush setting for painting over the skew? That happens sometimes, try a softer brush? The best option is to add a loop right in the middle of that and remove it after bake (assuming you have hard edges and the mesh shading doesn't change)

I did use a heavy brush. Using a softer brush gives the same error, just not as bad. Joe said that this is a limitation of the skew function and mentioned adding a loop on the low poly where the cut is but advised against removing the loop after the bake to avoid shading errors.

Neox · Nov 2019

huffer said:

Did you use a super heavy brush setting for painting over the skew? That happens sometimes, try a softer brush? The best option is to add a loop right in the middle of that and remove it after bake (assuming you have hard edges and the mesh shading doesn't change)

the shading will change, its a curved surface. just don't alter the geo post bake. don't

huffer · Nov 2019

I dare you to do it! Think about this scenario, you're doing this for a client and sending the bake for review. They don't accept that skewing error and ask you to fix it. Send out the model with a loop there? "What is this loop doing here, it doesn't support any geo or silhouette, please remove it". What next?

Yeah, its possible the shading will change if you bake with it then remove it. Yeah, it's not good and you should try something else. But if the shading doesn't change you can go for it. Either that or go the looong way around using the temporary skewmesh technique and object space bake.

guitarguy00 · Nov 2019

huffer said:

I dare you to do it! Think about this scenario, you're doing this for a client and sending the bake for review. They don't accept that skewing error and ask you to fix it. Send out the model with a loop there? "What is this loop doing here, it doesn't support any geo or silhouette, please remove it". What next?

Yeah, its possible the shading will change if you bake with it then remove it. Yeah, it's not good and you should try something else. But if the shading doesn't change you can go for it. Either that or go the looong way around using the temporary skewmesh technique and object space bake.

Interesting take actually. Would a client really care about a loop that contains maybe 18 verts though?

huffer · Nov 2019

guitarguy00 said:

Interesting take actually. Would a client really care about a loop that contains maybe 18 verts though?

Depends, I wish we all had big triangle budgets, 2K textures for everything and reasonable clients, but yes, it happens very often if you're doing props or environment work. For example, the work I'm doing now not only has low triangle budgets but low texture resolutions. Most small props are in the 100-200 triangle range. If you have a cylindrical prop and 18 verts to spare, you'll add a chamfer on top instead of a support loop for your bakes. This client will absolutely call on it if you leave it there.

HAWK12HT · Nov 2019

Looks to me you made it super hard crease for baking it down in the first place. I am referring to Earthquake's post where he shows acceptable view distances vs sharpness of edges for baking. Basically you make em a bit rounder (soft) than usual for good results.
Have this area more UV space, large 2k bake with AA stuff on.

http://wiki.polycount.com/w/images/8/85/Normal_edge_thickness.jpg << this

Stair-stepping on baked cut on corners? Even with skewing function.

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