[Amerie Maria] “Steve uses the rendered preview for fixing the edge width and motion blur”
The rendered preview is the only way to preview MB in mochaPro. There is no MB preview support in mochaAE – you’ll have to render out your masks and apply the MB within your compositing app.
For the Edge Width, you can see this in the Canvas by making te appropriate view selections – see image below.

You will need to do the following –
1) Switch On Mattes View
2) Switch On Alpha View
3) Switch Off RGB View
4) Switch Off Colorize Mattes View – paint bucket icon (only if you want to view the matte in grayscale)
HTH
RoRK
Intensive mocha & AE Training in Singapore and Other Dangerous Locations
Imagineer Systems (mocha) Certified Instructor
& Adobe After Effects ACE/ACI (version 7)