[kreativasas]

Hi.... another problem.

I understand how create a hole on a mesh, using subtract (i have a mesh and a cylinder, i subtract the cylinder from the mesh and all works).

But i need to create a hole on multiple very similar meshes.
so:
 - I load with assimp the first mesh
- apply the necessary transformation to geometrymodel  (to move the model over the cylinder)
 - i use Ab3d.Utilities.MeshBooleanOperations.Subtract(geometrymodel,meshgeometry)
- the geometrymodel resuts ok with the necessary hole
but when i load the next model, i move over the cylindre (like the first one) the subtract retuns: "Reference to an object not set to an object instance"

using subtract on 10 similar models the error appears random 1 o 2 times.....
anybody can help me?

note that the models are very similar and there is no reason to fail the subtract!!