This doesn’t really look like a SubD “display” issue… nor do I think it has anything to do with Perspective vs. Orthogonal projections… I can clearly see your perspective view updating, drawing, panning, rotating in real time…so obviously SubD drawing is fine. It’s only when you’re in a "feedback’ operation, do you see this lag…which tells me that something is most likely causing the display to recalculate and update the fragment mesh for every SubD object, on every feedback frame update…which is not good (obviously).
The differences I see in your ortho view are:
- You’re not in a shaded display mode
- There’s no clipping plane associate with the ortho view
When a clipping plane is active for a specific view, then certain things happen during feedback operations…
- Intersection lines are calculated and drawn for all objects that intersect the clipping plane
- Solid “fill” geometry is created and drawn for all closed surface objects that intersect the clipping plane.
The lag could possibly be caused by one or both of those things… You can try turning those off to see what happens (they’re both located in the Display Panel Tab near the bottom)… Turning those off will still give you the ability to use the clipping plane, you just won’t get intersections and fills. My guess would be the fills are causing this lag, since those are the most costly…but obviously this shouldn’t lag the way it is, and things have been optimized to prevent this kind of thing, so either something broke, or certain cases have been missed.
I will look at this tonight and tomorrow (thanks for the model and the report)…
I’ll let you know as soon as I find something.