How do I recenter the viewport of my 3D camera?

I'm working on a heavily modified version of the 3D Castle Maze demo for a haunted-house dungeon crawl.

onedrive.live.com/redir

The problem is, my 3D camera is centered in the wrong spot for my UI layer:

(the center of the 3D area is the green circle; I want it moved to where the yellow X is)

I think I could probably do this by writing a custom Effect Shader, but is there a better way, maybe using a DrawCanvas?

There is a system action: Set layout vanishing point

oh my gosh, that's exactly what I needed.

R0J0hound, one of the undersung heroes of Construct <3