I’m having trouble using the boolean union in blender.
I start by creating two NURBS curves and increasing their Bevel depth value. That gives me image  below. Then I convert both curves into meshes and Remove Doubles to get image  below but after converting faces to triangles and recalculating normals it looks like image  again. But then I take the boolean union and erase the original meshes and am left with image .
Some things I don’t understand and would appreciate an answer to:
- Why does a mesh created from a curve have so many double vertices that I need to remove afterwards?
- Why aren’t the normals all pointing outwards on the mesh created from a curve?
- What are the black edges on image ?
And most importantly:
Why did half my object disappear when I took the boolean union?
Thanks in advance!