Preview mesh for created Objects in rhinocommon File3dm

Rhino Developer
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1

When exporting a 3dm file from rhinocommon (ghpython); and loading that with ThreeJS 3dm loader. the brep objects don’t have a “mesh” attribute.
If I open this file in Rhino and save again. They would have the mesh for preview in threeJS.

My guess is that the objects don’t have a “Preview” mesh by default. Is there a way to add that to the attributes?
here is my code:

import Rhino

# create new rhino file
rh_file = Rhino.FileIO.File3dm()

# add layers
part_layer_index = rh_file.AllLayers.AddLayer("part", part_color)

# add objects to layer
attributes = Rhino.DocObjects.ObjectAttributes()

# add breps
attributes.LayerIndex = part_layer_index
    
for part in parts:
    rh_file.Objects.AddBrep(part, attributes)
2

Possible duplicate of: Three.js 3DM Loader fails to load BREPs

2 Likes
3

If you are creating objects programmatically, they won’t have render meshes by default. You need to call https://developer.rhino3d.com/api/rhinocommon/rhino.docobjects.rhinoobject/createmeshes to generate these before you export. Notice this is on a BrepObject, so you need to add the Brep to the doc first then get the BrepObject and run CreateMeshes on it.

1 Like
4

yes! thank you. sorry i did not see that.

5

alternatively, for loading to ThreeJS, I could convert the brep object to a mesh and then save the file with mesh objects.

https://developer.rhino3d.com/api/rhinocommon/rhino.geometry.mesh/createfrombrep

...

mesh_part = Rhino.Geometry.Mesh.CreateFromBrep(part, meshingParameters)
rh_file.Objects.AddMesh(mesh_part , attributes)
6

Yes, as long as you put meshes in the file, you can visualize them with three.js