Composition-Masks and Cancel Button

When using a rather complex composition as a mask for another composition, its quite easy to get Skatter into trouble. For example, when I take one grass-composition and use it as a mask for another grass composition (so the two different types of grass don’t grow in the same place), I can quite reliably get Skatter do calculate forever (freeze).

The cancel-button at the bottom of the Skatter Window is utterly unresponsive. So is SketchUp. The only way out of it is to use the Windows Task Manager to kill SketchUp.

Anyone else able to freeze Skatter / SketchUp like that? Is there a way to improve this?

(moved this thread out of the “Beta” category so that it’s visible to everyone)

Hi @jakob-winter We made specific efforts in Skatter’s architecture to avoid this kind of situations (UI freezing while computations are ongoing, unresponsive cancellation button, etc…) so this looks like a bug!

Could you send us a file that can produce that issue in a consistent manner? (or you could describe steps to create one)

Ok, I tried again. The good news: Skatter / SketchUp are not crashing - just freezing completely (can’t even minimize SketchUp… completely unresponsive).
The same goes for the Cancel-Button of course.

But eventually, Skatter will resolve its operation and everything is useable again. In the attached example it took my computer 90 seconds to resolve. Just edit the composition “Grass2” and select for the exclusive mask “Grass1”.

SkatterTest.skp (913.1 KB)


Thanks for the file, we can reproduce the issue.

What happens under the hood is that the calculation of the composition is non-blocking and cancelling it works as expected. But the calculation is relatively fast, even for this large composition, and the problem is not actually here.

Right after that part, Skatter starts another calculation: it computes the shape of the composition’s mask preview to draw it over your host (as blue lines). This part has not been made “non-blocking” so SketchUp freezes.

I guess we mostly did our tests with small composition masks so this never happened to us! We’ll optimize this for the next update.

@jakob-winter Until the next update, you can avoid freezes by:

  • Disabling the preview of the composition that uses a composition mask (the calculation that freezes won’t happen)
  • Keep the preview and use a host with less faces (the calculation will be faster)