multires errant vertices #126122

New Issue

Alessandro Padovani · 2024-08-09T10:35:21+02:00

Alessandro Padovani commented

2024-08-09 10:35:21 +02:00

System Information
Operating system: windows 10 22H2
Graphics card: GTX 1060

Blender Version
Broken: 3.6.14 and 4.2.0
Worked: never

Short description of error
The multires modifier generates errant vertices on some geometries.

Exact steps for others to reproduce the error
Load the included blend file, add multires to Original_HD object

Clicking on Generate subdivisions creates glitchy mesh like in #81645
Mesh does not subdivide correctly

**System Information** Operating system: windows 10 22H2 Graphics card: GTX 1060 **Blender Version** Broken: 3.6.14 and 4.2.0 Worked: never **Short description of error** The multires modifier generates errant vertices on some geometries. **Exact steps for others to reproduce the error** Load the included blend file, add multires to Original_HD object - Clicking on Generate subdivisions creates glitchy mesh like in #81645 - Mesh does not subdivide correctly

multires.jpg

18 KiB

multires.blend

218 KiB

Alessandro Padovani added the

labels 2024-08-09 10:35:22 +02:00

Alessandro Padovani commented

2024-08-10 06:43:02 +02:00

update.

If you try to "box mask" the errant vertices in sculpt mode then blender will crash.

**update.** If you try to "box mask" the errant vertices in sculpt mode then blender will crash.

Pratik Borhade commented

2024-08-12 11:11:03 +02:00

Hi, looks like this is due to non-manifold geometry?
If I add modifier on the other object (or the current object after removing the previous modifier), issue does not happen.
Did you import the object with modifier from other file (where file was saved in older version)?

Hi, looks like this is due to non-manifold geometry? If I add modifier on the other object (or the current object after removing the previous modifier), issue does not happen. Did you import the object with modifier from other file (where file was saved in older version)?

Pratik Borhade added

Status

Needs Information from User

and removed

Status

Needs Triage

labels 2024-08-12 11:11:12 +02:00

Alessandro Padovani commented

2024-08-12 11:25:21 +02:00

Thank you for looking at this.

Yes, the file is imported in blender 4.2 from another app, but it is also validated by blender so the geometry should be good. As for removing then re-adding the modifier it doesn't work here, it would be wonderful if it does.

my steps:

open the test file in blender 4.2
remove the multires modifier
re-add the multires modifier then rebuild subdivisions, the issue is still there

This bug is also reported elsewhere, though I stripped down the test file so it should be easier for you to test. See #81645 #107118. Let us know thank you.

Thank you for looking at this. Yes, the file is imported in blender 4.2 from another app, but it is also validated by blender so the geometry should be good. As for removing then re-adding the modifier it doesn't work here, it would be wonderful if it does. my steps: 1. open the test file in blender 4.2 2. remove the multires modifier 3. re-add the multires modifier then rebuild subdivisions, the issue is still there This bug is also reported elsewhere, though I stripped down the test file so it should be easier for you to test. See #81645 #107118. Let us know thank you.

Pratik Borhade commented

2024-08-12 11:47:54 +02:00

Thanks. Strange, re-inserting the modifier works here. Attached the file below.
BTW, what importer did you use?

Thanks. Strange, re-inserting the modifier works here. Attached the file below. BTW, what importer did you use?

multires-fixed.blend

170 KiB

Alessandro Padovani commented

2024-08-12 12:04:39 +02:00

Your fixed file seems good here. Can you tell me exactly what are your steps ? May be I miss something trivial. If I remove the multires modifier it leaves me with the base resolution version, I don't regain the original model it is a destructive operation.

So how do you remove the modifier ? I just press the "remove modifier" cross, do I have to do something else ?

p.s. The importer is diffeomorphic to import daz studio files.

https://diffeomorphic.blogspot.com/
https://www.daz3d.com/

Your fixed file seems good here. Can you tell me exactly what are your steps ? May be I miss something trivial. If I remove the multires modifier it leaves me with the base resolution version, I don't regain the original model it is a destructive operation. So how do you remove the modifier ? I just press the "remove modifier" cross, do I have to do something else ? **p.s.** The importer is diffeomorphic to import daz studio files. https://diffeomorphic.blogspot.com/ https://www.daz3d.com/

remove.jpg

33 KiB

Pratik Borhade commented

2024-08-12 12:22:21 +02:00

What I did is:

Remove modifier
Add Multires modifier again
Subdivide once from multires modifier panel

What I did is: - Remove modifier - Add Multires modifier again - Subdivide once from multires modifier panel

Alessandro Padovani commented

2024-08-12 12:30:25 +02:00

Not good then. That way you lose the original geometry thus the original HD details. If you subdivide the generated geometry will not be the same as the original HD model. So your procedure is a destructive operation and it defies the purpose of multires.

That is, unsubdivide serves for us to retain the original HD details.

please try this:

add a multires modifier to the original mesh
rebuild subdivisions, here I get the issue

p.s. Of course you need the multires viewport level to 1 otherwise it's not visible on the viewport, also disable simplify if you use it.

Not good then. That way you lose the original geometry thus the original HD details. If you subdivide the generated geometry will not be the same as the original HD model. So your procedure is a destructive operation and it defies the purpose of multires. That is, unsubdivide serves for us to retain the original HD details. please try this: 1. add a multires modifier to the original mesh 2. rebuild subdivisions, here I get the issue **p.s.** Of course you need the multires viewport level to 1 otherwise it's not visible on the viewport, also disable simplify if you use it.

Pratik Borhade added

Status

Needs Triage

and removed

Status

Needs Information from User

labels 2024-08-12 12:33:32 +02:00

Alessandro Padovani commented

2024-08-12 20:44:00 +02:00

update.

I was inspired by your idea and tried reshape to get the original details but it doesn't work the mesh "explodes" because the vertex order is not the same. Let me know if you need more information or if you have some other workaround we can try. Thank you.

steps:

load the test scene
remove multires
add multires and subdivide
reshape from original, the mesh "explodes"

update. I was inspired by your idea and tried reshape to get the original details but it doesn't work the mesh "explodes" because the vertex order is not the same. Let me know if you need more information or if you have some other workaround we can try. Thank you. steps: 1. load the test scene 2. remove multires 3. add multires and subdivide 4. reshape from original, the mesh "explodes"

reshape.jpg

18 KiB