this is a quote from Jay's post on 3/21:
"I'm not sure what you mean by translate"
apology for taking ten years to reply now.
By translate, I mean designate sets of vertices or faces of a solid model and 'drag' them elsewhere, meanwhile, the rest of the model stays immobile. It's (apparently) not possible with solid models to the extent that it is, for example, with meshes or polylines.
Thanks for beaucoup helpful input, everybody; the solids are going swimmingly now.
Anybody proficient in 2D autocad will have no trouble delving into 3D. 3d comes nearer to representing the reality of objects than 2d, and as such is more readily understood, a lesser abstraction of the model. And for presentation purposes, with 3d you're free do derive relevant views and sections straight from the model. So you retain all previous capabilities and gain additional means to understand and present the designed object.
Not everybody needs 3d, but doubtless many who don't know it would profit from it.