Crash when setting a vertex position using Python

Question

I am a developer of a physics simulation engine, and I want to connect it to Blender, so I can render simulations in Blender. The physics engine simulates soft bodies. Deformation of meshes occurs, usually at each time step.

I use Blender 3.6.4 on Windows.

The approach I took is the following:

• Just after the first time step of the simulation, I create a new collection, with a new object, with a new mesh using the data I just computed from the simulation:

new_mesh = bpy.data.meshes.new(object_name)
new_mesh.clear_geometry()
new_mesh.from_pydata(object_data["position"], {}, object_data["faces"])
new_mesh.update()
new_object = bpy.data.objects.new(object_name, new_mesh)
collection.objects.link(new_object)

• After the following time steps, I update the vertices and insert a keyframe on them:

obj = collection.objects[object_name]
pos_id = 0
for v in object_data["position"]:
    if len(obj.data.vertices) > pos_id:
        obj.data.vertices[pos_id].co = v
        obj.data.vertices[pos_id].keyframe_insert("co", frame=iteration)
        pos_id = pos_id + 1

What do you think about the approach? Can you suggest a more appropriate strategy?

In the meantime, the current approach makes Blender crash randomly: not always the same time step, not always the same stack trace. However, I often have the crash happening on obj.data.vertices[pos_id].co = v, leading (sometimes) to the following stack trace:

blender.exe         :0x00007FF648F1C600  blender::deg::`anonymous namespace'::deg_graph_node_tag_zero
blender.exe         :0x00007FF648F1CC20  blender::deg::graph_id_tag_update
blender.exe         :0x00007FF648F1D700  DEG_id_tag_update
blender.exe         :0x00007FF6491C1280  rna_Mesh_update_positions_tag
blender.exe         :0x00007FF6490FBC40  rna_property_update
blender.exe         :0x00007FF649107340  RNA_property_update

Any idea how to solve this crash?

Thanks