Hi Michael,
So I just want to be sure you understand. Using your last scenario, isnt the issue.

I perform your last scenario of drawing a sphere and starting the line command. I "Do" see a performance difference with snaps on and off, but it is very slight, and on my part, expected and "works fine".

Here's the difference:

Turning on a command, actually "fixes" the issue I was refering to. With just a sphere, and "no command running" (Selection mode), the erratic behavior is present. The rotation and panning "jumps" with large delays in movement (When doing simultaneous movement) In a single maximized viewport only (all of them, whether its front,back or 3d etc)

So to recap, Only in selection mode with a 3d object, not performing anything other than navigation with simultaneous device movement.

Hi Burr, thanks for the additional explanation.... That's kind of mysterious though that it only happens in selection mode.

One thing that I don't quite follow is actually why you would want to do that - what are you trying to do where you find yourself moving both the view and the mouse at the same time, isn't it hard to select objects at the same time that your view is changing?

- Michael

It's more about trying to be "expert" with my 3d navigator. For instance, using the curve tool, then drawing and rotating around the sphere for various pick points! Using my spacenavigator at the same time as drawing and constructing, with 2 hands, in the 3d viewport...

But it is a bit unconventional, and not a normal workflow for me. Hence I didnt want to push for totally figuring it out. I was looking to see if it was a simple explanation found with some understanding of the underlying process.

It may very well be limited to "only my system", in which case, a bunch of time doesnt need to be wasted on why, what etc. on your end.

Hi Burr,

> For instance, using the curve tool, then drawing and rotating
> around the sphere for various pick points!

Does that particular one actually work ok for you though? The curve tool is in a drawing command, not selection mode...

- Michael

Yes, that was the revalation during this discussion.... My first impression just came at initial launch after updating my SN device drivers..... So, outside of a command, I just need to flick the mouse out of the viewport....... :)