Photogrammetry Meshobject

Rhino Rhino for Windows
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1

Hey guys,
i currently take part in a course about photogrammetry at college.
We use Meshroom as program.
I was wondering how I can make the exported Meshobject manageable to work with and maybe split it or transform it, make it a solid body maybe.
Do you have any suggestions on that?

File size is too big to upload…

Unbenannt.PNG
Unbenannt.PNG1920×1050 79.5 KB

!What
mesh

ID: f35ad5dd-944b-4ce2-8ed3-831afb137761 (2)
Object name: TexturedMesh
Layer name: Layer 01
Render Material:
source = from obj
index = 0

Geometry:
Valid mesh.
Open double precision polygon mesh: 112006 vertices, 184906 faces
Bounding box: (-0.815,0.338,-1.103) to (0.599,1.725,-0.992)

mesh

ID: 92ea4c64-38cf-44e9-a1fd-b6439ead4865 (3)
Object name: TexturedMesh
Layer name: Layer 01
Render Material:
source = from obj
index = 1

Geometry:
Valid mesh.
Open double precision polygon mesh: 85671 vertices, 149574 faces
Bounding box: (-0.813,0.335,-1.112) to (0.564,1.727,-0.989)

mesh

ID: d0c62458-33e3-4d60-b667-5a0e96c42f62 (4)
Object name: TexturedMesh
Layer name: Layer 01
Render Material:
source = from obj
index = 2

Geometry:
Valid mesh.
Open double precision polygon mesh: 53636 vertices, 90975 faces
Bounding box: (-0.815,0.343,-1.111) to (0.531,1.653,-0.995)

mesh

ID: 4aa165b1-d5c2-4895-8f80-f33e2356b4b9 (5)
Object name: TexturedMesh
Layer name: Layer 01
Render Material:
source = from obj
index = 3

Geometry:
Valid mesh.
Open double precision polygon mesh: 77630 vertices, 136531 faces
Bounding box: (-0.740,0.336,-1.111) to (0.598,1.722,-0.991)

mesh

ID: 8153fff4-3096-4a17-850f-1251c8aba233 (6)
Object name: TexturedMesh
Layer name: Layer 01
Render Material:
source = from obj
index = 4

Geometry:
Valid mesh.
Open double precision polygon mesh: 69901 vertices, 120267 faces
Bounding box: (-0.788,0.337,-1.114) to (0.603,1.646,-0.997)

mesh

ID: bb4743d0-3ed5-45c1-bf67-f5feeb0a5280 (7)
Object name: TexturedMesh
Layer name: Layer 01
Render Material:
source = from obj
index = 5

Geometry:
Valid mesh.
Open double precision polygon mesh: 27966 vertices, 45295 faces
Bounding box: (-0.794,0.377,-1.100) to (0.570,1.689,-0.996)

Mesh totals: 6 meshes, 426810 vertices, 727548 polygons

Thanks,
-Paul

2

What do you want to do with the mesh?

I use Rhino with much larger meshes from photogrammetry, millions of vertices, and can split and trim the meshes. I do have to occasionally wait for up to several minutes for the command to complete. For other mesh manipulations Rhino may not be the best software.

Creating a usable NURBS object from a large mesh requires creating a new object using the mesh as a reference. The mesh can be contoured and sectioned, intersected with surfaces, and projected onto to create curves to use in creating the new object. Usually the resulting curves will need to be simplified using Rebuild, RebuildCurveNonuniform or similar to obtain curves which are simple enough to use directly.

Another method of creating objects from meshes is using Patch with the vertices as the input points, though the mesh may need to be sampled or simplified to keep from overwhelming Patch with too many points. I usually create an initial surface and then use Patch to refine the shape of the surface (initial surface option in Patch) instead of hoping that Patch creates a satisfactory surface on its own.

1 Like
3

Hey David,
We want to do very basic stuff with it. The task is to build an environment with the things we scanned. So we need to trim and split, that’s actually it.
Is there any way to make a solid of a mesh like extruding the bottom to get a block shape for example?
How do you split and trim? With lines or surfaces and do you convert the mesh to nurbs?

Thanks for the feedback!
-paul

4

Hi Paul - don’t do that. There are a number of commands under the Mesh menu that can help - some are finicky, to be sure, espoecially if the mesh is ‘questionable’ (Check command will give some information) say with non-manifold edges or duplcate faces.

–Pascal

1 Like
5

@pascal I assume you mean don’t use ToNURBS to convert the mesh directly into a NURBS polysurface. I agree using ToNURBS with this mesh is an extremely bad idea with an input mesh of that size, and the result, if the command completes, would be useless. I also assume you do not mean that it would be a bad to create a NURBS model with appropriate complexity using the mesh as guidance. Creating a new NURBS model may be appropriate depending on the level of fidelity needed relative to the mesh model and the use of the result.

1 Like
6

Ok, thanks I’m going to try these out. Never used them before.
Thank you!

-paul

7

Have you tried QuadRemesh command?

8

Yes with surfaces, but I haven’t used it recently. I have used other software for mesh software in the past.

9

Rhino really struggles with meshes, or at least I do inside Rhino… if you are not after NURBS convertion then you might consider using other software to split, trim and cap the mesh into a closed solid. (Blender, Cinema4D, etc)

1 Like
10

Little Update.
The course ended and the professor finished before actual end so we weren´t able to finish…
In the end I used the meshcommand “deletefaces” to clean the model. That worked out well.
I didnt follow split and trim any longer since there was no need for it.

A problem that appeared was that the textures from meshroom, all called texture 1001 were used multiple times. So, if I imported one object and then another, rhino would use the texture from model 1 for model 2. Is there any way to solve this in a faster way? Only way I found was making a material for each texture and renaming the textures.

Thanks for the help!
-Paul