Save only specific element of step file

[VoRodin]

Hi,

After loading geometry from the step file, how can I select only a specific object for manipulation/export?

By default, it merges everything into a single mesh.

Best regards

[VoRodin]

My workaround right now is to load via opencascade, decompose specific entity and construct mesh again via
mesh = mrmeshnumpy.meshFromFacesVerts(faces, verts)

[oitel]

Hello, MeshLib has two functions for importing STEP files: MR::MeshLoad::fromStep and MR::MeshLoad::fromSceneStepFile. The former loads all data as a single mesh, while the latter preserves the object structure. You could use it and then get all meshes from it using the getAllObjectsInTree function.

[oitel]

Yes, use the loadSceneObject method instead of loadMesh.
We don't yet have the direct equivalent of getAllObjectsInTree in Python, but you could iterate manually:

def collectMeshes(obj):
    results = []
    if mesh := obj.extractMesh():
        results.append(mesh)
    for subobj in obj.children():
        results += collectMeshes(subobj)
    return results

obj = loadSceneObject(filename)
meshes = collectMeshes(obj)

[VoRodin]

Perfect! Your help greatly streamlined my workflow🙂

[VoRodin]

@oitel, I have a follow-up question, how can I apply transformations assigned to children meshes in the original file?

[oitel]

You can extract the transformations from the objects and apply them to the meshes:

if mesh := obj.extractMesh():
    mesh.transform(obj.worldXf())
    results.append(mesh)

[VoRodin]

@oitel, and to check that transformation was applied I should check properties of mesh bounding box before and after transformation, correct?
Just to be clear, it should be like Apply in Blender

EDIT: Please ignore this question, it works as intended 👍