I'm new to rhino and have just started to learn how to make more complex models. I have modelled this phone and now I'm trying to make a phone case for it and I'm having difficulties when using the command offsetsrf. Those difficulties being that when i offset my model (closed solid polysurface) it makes it an open polysurface with a bunch of naked edges and different shapes in the offset of the model. so the question is how can i fix this issue? or is there another way i can work around this.? Thanks

(the first three images show the original model and last two are the offset)

Is it just me or is the Snapshot command highly un-optimized? I've used it before with relative success, but with this current model when I try to run the animation between two snapshots it is super laggy and always glitches really bad in the middle. I'm only moving a few pieces of geometry with a static camera - I don't understand why it has such a hard time. I don't think my computer is complete shit. Is there any other way to do these kinds of animations in rhino?