Hello!
I tried to create a box dropper with two types of boxes: normal and anti-weighted.
I've got this effect with trigger_push and filter because trigger_gravity works only with player.
It works fine, but I can't get a zero gravity, as in Portal: Prelude with trigger_push.
How can I get this without coding?

Use a trigger_vphysics_motion. It allows you to scale the gravity inside it (negative values let objects fall to the ceiling) as well as a constant force, like trigger_push.

If you want both the cubes and the player to fall to the ceiling, you must use both a trigger_vphysics_motion and a trigger_gravity.

It works, thank you very much!