Blender to Rhino hangs program

I was doing some tests yesterday and I didn’t manage to successfully send the object from Blender to Rhino.

Tested with Rhino 7 and 6.

Yesterday I had a similar error message to this one I found somewhere on the internet:

Mesh: ON_Mesh.m_T.Count() = 1491 (should be 0 or 6884=vertex_count)

Today my Rhino just hangs when I try to import simple Blender geometry.

How can I troubleshoot this problem? A good connection between Rhino and Blender is something I’m looking forward to.

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Hey @Czaja! Could you share with us the stream & commit that’s causing the rhino hang? There are some differences in mesh handling, and we’d want to be able to debug this :slight_smile:

Hi, @dimitrie
Here you go:

Okay figured this one out! Thanks for the link to the stream. It’s because of invalid texture coordinates coming in from Blender for that mesh. Note, when I say invalid I say “invalid from Rhino’s point of view”.

Not setting them gets rid of the error and bakes the sphere. If we’re setting them, things go crazy :slight_smile:

General information about this mesh:

Mesh does not have any degenerate faces.
Mesh does not have any ngons.
Mesh does not have any extremely short edges.
Mesh does not have any non manifold edges.
Mesh does not have any naked edges.
Mesh does not have any duplicate faces.
Mesh does not have any faces with directions different from the mesh as a whole.
Mesh does not have any self intersecting faces.
Mesh does not have any disjoint pieces.
Mesh does not have any unused vertices.
ON_Mesh.m_T.Count() = 240 (should be 0 or 42=vertex_count).

ID: c6fc40bd-2e05-4ff4-b306-dd7c594bcbb8 (184)
Object name: Mesh: ON_Mesh.m_T.Count() = 240 (should be 0 or 42=vertex_count).
Layer name: Default
Render Material: 
  source = from layer
  index = -1
Attribute UserData:
  UserData ID: CE28DE29-F4C5-4faa-A50A-C3A6849B6329
  Plug-in: 17b3ecda-17ba-4e45-9e67-a2b8d9be520d
    description: User text (1 entries)
    saved in file: yes
    copy count: 2

  Invalid mesh.
  Closed double precision polygon mesh: 42 vertices, 80 faces with normals
    Bounding box: (-951.058,-1000,-1000) to (951.058,1000,1000)

The Check command on that mesh actually is not very informative - it gives us the same error message.

Following up, I’ve raised an issue that we’ll tackle next week onwards: Rhino: Texture Coordinates on Meshes cause invalid meshes · Issue #785 · specklesystems/speckle-sharp · GitHub

A current workaround would be to use grasshopper to receive that mesh - it’s what I did to actually get it in Rhino - and bake it from there, with “allowing to bake invalid objects” when it will complain.

Those texture coordinates… I hope you will find some solution for that.
I struggle a lot with texture mapping when exporting from Rhino to other programs.

Speaking about the workaround, I can’t receive the geometry through Grasshopper.
It looks like it should be very easy, but no GH preview is showing, and bake attempts do nothing also.

I do get the name though.

Hi @Czaja! When actually googling around texture coords in rhino I’ve stumbled over a few of your posts on the Rhino forum on this :joy: @Jedd got triggered and he’s looking into solving this - we’ll need to figure out what the existing conventions are around the software we support, and take a decision on how to encode them in Speckle.

Regarding the Grasshopper workaround, you need to expand the object a couple of times, as documented here:

At one point you’ll see a “collection” key (if I’m not mistaken) and that’s where the meshes will be.

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Hah, I’m glad that bringing those problems over and over again didn’t go to waste!

Blender because of its nature and community will always have something interesting for the Rhino user. That’s one of the reasons why I’m interested in your solutions to streamline exchange.

Thanks, I got my test mesh now! :slight_smile: