Backface Culling on model when starting Retopoflow 3

[Haikuyori]

PLEASE READ THE FOLLOWING AND USE THE TEMPLATE TO POST YOUR ISSUE

Questions not directly related to the RetopoFlow project are considered general and should be posted elsewhere (e.g. git, blender, python, etc).

Before raising the issue, please check the following first:

• [ ] Read through the README.md file in the branch used to assure the process taken is correct
• [ ] Check the existing issues and pull requests to make sure the issue has not already been reported and/or fixed.
• [ ] You can replicate the bug and will provide as much info as possible with blend files, screenshots, logfiles, as well as show the expected result and actual result.

 

Issue Template

---

Please prefix your issue name with one of the following: [BUG] [PROPOSAL] [QUESTION]

Retopoflow Version: 3.4.2

Blender Version/Hash: 4.0

Platform Version/Distribution: ??

 

Issue:

Backface Culling on the model when starting Retopoflow 3, can't seem to turn it off

[vxlcoder]

Hi @Haikuyori.

I'm not sure if you mean the high-poly source mesh is not showing backfacing geometry, or if the low-poly retopo target mesh is not showing backfacing geometry.

If you mean the high-poly, you can show the backfacing geo by going RF > Options > Viewport Dispaly > Optimize Shading > Off. This will disable RF's optimizations for the meshes. Alternatively, you can recalculate the normals of high-poly source meshes, by editing source mesh, select all (A), Mesh > Normals > Recalculate Outside. RF assumes that you're working on a (nearly) closed mesh, but when the mesh isn't closed you can simply turn off optimized shading.

If you mean the low-poly target, RF will still render these, but they are not selectable by default. (Usually, your retopo target should have faces that point outwards). You can fix the backfacing-ness a few ways the same as above or in RF: select all (A), Options > Target Cleaning > Normals > Recalculate. To make them selectable, even when backfacing, RF > Options > Selection > uncheck Block Backfacing.

If you meant something different when you say "Backface Culling on the model", please let us know a bit more details and maybe include a screenshot so we can see what you're seeing. Thanks.

[Haikuyori]

i am using a high polycount mesh, I was able to "fix" it by changing EVEE to Cycles, I was hoping to fix it in EVEE, Ill use your suggestions, thanks!

[Haikuyori]

the Recalculate outside worked, thanks!

[Haikuyori]

I should probably make another ticket for this, but when I use PolyStrips I get a message that I have bad symmetry, when I flip bad symmetry the Polystrips hide under the face, how can I fix this? thanks!

[Haikuyori]

Also, when I use tweak it makes the vertices snap to the center vertex, I am losing my mind.

[vxlcoder]

RetopoFlows wants all the geometry to be on Positive X side of the model when working with Mirror Symmetry. If you have geometry with negative X values, then you'll get that warning. This can also cause weird behavior with tweak and other tools, as you noted in your follow-up comment.

Flipping the bad symmetry will simply negate all the X values, flipping the geometry to the "correct" side of the mesh.

But, if the mesh isn't perfectly symmetric or the mesh's origin isn't exactly in the middle of the mesh, then flipping can put the verts inside or outside the source mesh.

You can fix this by Options > Target Cleaning > Snap Vertices > All (maybe set push distance to 0 first), then click Normals > Recalculate to make sure normals are facing outwards.

Once you get all the geometry on the "correct" side and then work on that side, RF should behave as expected.

We know that it's not ideal to always work on the Positive X side of the mesh. this is something that we are working on.

[Haikuyori]

Still getting this and after Snap Vertices I get this after recalculate normals the vertices hide behind the face and i cant select them

[Haikuyori]

after doing it again, the vertices wont snap back to surface after Snap Vertices>All and then Normals>Recalculate, this is getting wierd

[vxlcoder]

that is weird. Any chance you can send us your .blend file so we can see why RF is behaving so strangely?

retopoflow@cgcookie.com

thanks for helping us debug this!

[Haikuyori]

sent! thanks!