Hello!
It would be really helpful if these buttons gave visual feedback on their state. In other words, if the 'Synchronize cam' feature is active, the toolbar icon should look different.
Does the Rhino SDK allow for that?
Turned off:
Turned on:
You get the point.
Thanks!
Tupaia , thanks a lot for your request! 
In SketchUp, for example, the corresponding icons you've mentioned are already visually displaying whether or not that function is active, so it may just be that Rhino itself does not allow us to achieve that. I'd see no reason why we wouldn't have added it if it's implemented in SketchUp, so I'll make sure to ask our developers to which I'll also forward your feedback. Thank you!
