01-09-2022, 05:42 PM (This post was last modified: 01-09-2022, 06:57 PM by tecnnt.)
Hello, I checked the forum and the document, and mentioned that the fabric does not support non-manifold mesh.
Forgive me for my unprofessional, after I read the document you shared, I probably understand the non-manifold mesh.
But what I don't understand is what a 2-manifold is?
When I tried to merge the model fixes into the mesh in Blender, the repaired simulations were sometimes even weirder than the unrepaired ones (in skin mode), and there was little difference between before and after the fixes in Cloth mode(This one can be ignored, which may be caused by my incorrect configuration. Modified at 01:56:30 on September 2, 2022)
And I see that OBI seems to automatically merge meshes?
So Obi will automatically deal with repairing some non-manifold meshes?
==============================================================
"Generate a list of merged mesh vertices, ignoring uv and normal seams."-Documen
02-09-2022, 11:17 AM (This post was last modified: 02-09-2022, 11:18 AM by josemendez.)
(01-09-2022, 05:42 PM)tecnnt Wrote: Hello, I checked the forum and the document, and mentioned that the fabric does not support non-manifold mesh.
Forgive me for my unprofessional, after I read the document you shared, I probably understand the non-manifold mesh.
But what I don't understand is what a 2-manifold is?
Hi!
A 2-manifold mesh is a mesh that can be unfolded into a continuous, flat 2D surface. Think of a t-shirt: you can cut it at the sides, and then unfold it flat into a table as a single piece of cloth. Basically any real piece of cloth is considered a 2-manifold, non-manifold cloth surfaces could not exist in the real world.
(01-09-2022, 05:42 PM)tecnnt Wrote: And I see that OBI seems to automatically merge meshes? So Obi will automatically deal with repairing some non-manifold meshes?
No, Obi does not automatically merge meshes or fix non-manifold geometry. All it does is close UV/Normal seams in the mesh, to prevent the simulation from creating gaps at those seams.
A 2-manifold mesh is a mesh that can be unfolded into a continuous, flat 2D surface. Think of a t-shirt: you can cut it at the sides, and then unfold it flat into a table as a single piece of cloth. Basically any real piece of cloth is considered a 2-manifold, non-manifold cloth surfaces could not exist in the real world.
No, Obi does not automatically merge meshes or fix non-manifold geometry. All it does is close UV/Normal seams in the mesh, to prevent the simulation from creating gaps at those seams.
let me know if you need further help,
kind regards
Whether it can be understood as: whether the model itself is a perfect manifold geometry. Obi supports as long as the geometry can be flattened into a piece of cloth?
I have uploaded an attachment. I think this model should not satisfy Manifold Objects. Because I did a grid split of orders and edges. However, it can be simulated normally in OBI. So I'm conflicted about these two concepts
05-09-2022, 07:33 AM (This post was last modified: 05-09-2022, 09:38 AM by josemendez.)
(03-09-2022, 04:28 AM)tecnnt Wrote: Whether it can be understood as: whether the model itself is a perfect manifold geometry. Obi supports as long as the geometry can be flattened into a piece of cloth?
I have uploaded an attachment. I think this model should not satisfy Manifold Objects. Because I did a grid split of orders and edges. However, it can be simulated normally in OBI. So I'm conflicted about these two concepts
Hi,
I just inspected your mesh, and it's a perfect 2-manifold.
Asking blender to find non-manifold features only marks the outer edges and a few inner faces that are detached from the neighboring ones. This is because blender considers open edges to be non-manifold features (since Blender considers 2-manifolds need to also form a closed volume).
Other than the open edges (which most apps other than Blender won't consider non-manifold) there's no non-manifold features: no floating vertices, no edges shared by more than 2 faces, no adjacent faces with opposite winding order, no zero area faces, no zero length edges, etc. The mesh is perfectly fine as far as Obi is concerned.
I just inspected your mesh, and it's a perfect 2-manifold.
Asking blender to find non-manifold features only marks the outer edges and a few inner faces that are detached from the neighboring ones. This is because blender considers open edges to be non-manifold features (since Blender considers 2-manifolds need to also form a closed volume).
Other than the open edges (which most apps other than Blender won't consider non-manifold) there's no non-manifold features: no floating vertices, no edges shared by more than 2 faces, no adjacent faces with opposite winding order, no zero area faces, no zero length edges, etc. The mesh is perfectly fine as far as Obi is concerned.
Thank you for your reply. According to my use in recent days, it is as you said.
