Propeller rotation axis off-axis during voxelization about fluidx3d

[ProjectPhysX]

Hi @wjsjtu123,

when you load an .stl mesh, by default the (rotation) center of the mesh is set to the center of its bounding box. This is correct for 2- or 4-bladed propellers, but fails for 3- or 5-bladed propellers; their rotation center is offset from the bounding box center. Here an illustration:

You can figure out this offset with some geometry.

The solution is to manually correct the position of the mesh center, with

float3 offset = float3(...);
propeller->set_center(propeller->get_bounding_box_center()+offset);

The specified mesh center is used as the rotation center during lbm.voxelize_mesh_on_device(propeller, ...) and propeller->rotate(...).

Kind regards,
Moritz