How do I apply an InstanceObject’s transform to the meshes it contains?

@binigya wrote:

Hey all!

I am having an issue with correctly applying the position of a mesh according to the block instance it belongs to.

So, as the question says, how do I exactly apply the transform data of a CRhinoInstanceObject into an mesh of type currentONMesh. (I am using the C++ API, btw)

I have tried multiple approaches like :

a) Using the Transform() method :

			ON_Mesh* currentONMesh = currentRhinoMesh.m_mesh;

			const CRhinoInstanceObject* currentMeshInstaceObj = currentRhinoMesh.m_iref_object;

			ON_Xform instanceTransform = currentMeshInstaceObj->InstanceXform();

			currentONMesh->TransformUserData(instanceTransform);
			currentONMesh->Transform(instanceTransform);

b) Individually changing the mesh’s vertices as:

            const CRhinoInstanceObject* currentMeshInstaceObj = currentRhinoMesh.m_iref_object;
			ON_3dPoint instancePoint = ON_3dPoint::Origin;
			instancePoint.Transform(currentMeshInstaceObj->InstanceXform());

In this approach, after I get the instancePoint, I use it’s x, y, z values as the values for the vertices of the mesh.

Both of these approaches are not working for me.

So, what would be the correct way to achieve this?

Need help.

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