I’m going to pose this question with simple scenarios:
Lets say I have two cubes next to each other, and I union them. How do I get rid of the “seam” where the two cubes used to touch? There is an edge that runs down the middle of these co-planar faces.
In SketchUp I can draw a rectangle on the face of a flat surface and extrude that rectangle out of the surface or into the surface. I can do the same thing in Rhino, but I have to split the surface with the curve, rejoin the two pieces to get that “seam” so that I can extrudesrf. In a more complex situation, if I have a polysrf I want to put a rectangular depression into, I need to explode the polysrf, split the target face with the rectangular polyline, rejoin all the faces into one polysrf and then extrudesrf inward. I know I could do boolean difference, but I like to avoid it. How do I add “seams” into a polysrf without this long workflow? “Seams” are useful to me because I can ctrl-shift click them and manipulate them.