Doesn't work for me. Here's what i did:
- Attach RootCollisionNode to Root NiNode.
- 'Transform\Apply' to parent NiNode of the source NiTriShape (the stem). As you said, it moves the translation, rotation and scale from the NiNode to it's NiTriShapes.
- 'Transform\Apply' to the NiTriShapes of this NiNode. It gives all of them a translation and rotation of 0 and a scale of 1.
- Copy and paste the branch of the NiTriShape (the stem) to the RootCollisionNode.
- Set 'Has Normals', 'Has Vertex Colors' and 'Has UV' in the NiTriShapeData to 'No'.
- Delete the branches of the 'NiMaterialProperty' and 'NiTexturingProperty' from the NiTriShape.
The Collision box has the correct scale and position, but when i delete the 'NiTexturingProperty' there, the texture of the stem is gone although it is still in the source 'NiTriShape'. Testing this mesh ingame results in an immediate CTD.