The collision mask is very much integrated into CF2.5. When you create a backdrop or quick backdrop, or when you use the "add to backdrop" action of an active object, you can choose to make it either...MuddyMole Today, 06:42 PM
The collision mask feature allows you to test any pixel to see if it is an obstacle:
From the help file:
"Value of collision...
https://images.squarespace-cdn.com/content/v1/5d226097fdd42c00018d73f9/1582409431201-BS5VCAWTN01ZYKOUAW46/ke17ZwdGBToddI8pDm48kLrCtcCYMJoFeQU5ToTim5pZw-zPPgdn4jUwVcJE1ZvWQUxwkmyExglNqGp0IvTJZamWLI2zvY...IsaacBoy Yesterday, 10:33 PM