Do the vertices of the geometry change, when I rotate the mesh?

I have two objects which I merge together with the help of the [three-csg-ts]( module. So far this has worked splendidly, until now. What I had done before, is to merge different geometry, which all exists as children of the same parent mesh.

Now, I’d like to merge two of these parent meshes together. I have rotated 1 mesh via the rotateX function, and when trying to merge the two meshes together. It merges both of them on a flat surface. This makes me understand that when I call the rotateX function on a mesh object (Object3D in this case). It does not effect the positions of the vertices of the geometry. Is that a right assumption? And if so, what can I do to apply the rotation of my mesh. So that the vertices of my geometry align?


this tuto explain how local or world coordinate system works when we go from scene to children and children of children etc . super tuto i ve just read this afternoon . thank it , i am now able to create pivot vertex use for arm of robot etc .

to answer to your question . position of vertices dont move inside geometry of a mesh when you change position, rotate or scale .the transformation is always according local coordinate system of parent apply on the whole vertices .