> I am pretty convinced this issue has only started since the verification was introduced as I have always used 'Stop on collision' without waiting for anything. i.e. waiting for verification to complete.
Verification has existed since at least 2015. You have always been able to see it (and control it) by going to the "Info" tab and scrolling to the bottom. Most people never noticed it though.
The behavior of Stop-on-collision making simulation stay behind verification is new. That's why were making verification more obvious with the grey veil on the timeline.
> If I don't make any changes or regenerate the tool paths then the simulation will run immediately with no juddering.
>
> If I make changes, regenerate or I 'Clear Cach data' it will force the issue every time.
Ah, this probably explains it. After you regenerate a toolpath, Fusion will start recalculating the in-process stock (IPS) in the background. IPS calculation, aside from using CPU time, uses the same stock-simulation engine that simulation uses. There will be some contention.
Try opening the "Task Manager", it's in the "Manage" group on the tool bar. The task manager will show you any running generation or IPS tasks. Is simulation smooth when the task manager shows that there are no tasks and juddery when there are IPS tasks running?
You can go to the "Utilities" tab and under "Actions" turn off "Automatic In-Process Stock Generation". Then when you edit toolpaths, Fusion won't create lots if IPS tasks and simulation should be smoother immediately.
Brek Miller
Software Engineer