Eh? Come again? Don't really understand what it is you want to do, maybe annotate your patch to describe what you want to happen.

Humm... ok.

This goes like that: There are 5 matrices, which are essentially the same, delayed a couple of seconds from one to each other. There is a character moving from right to left.

What I need to find out how is to make a moving mask that follows the character in each matrix, so that I can join every delayed matrix into a single one where the character is moving continuously.

What I actually have are the delayed matrices but haven´t found a way to make the moving mask. Any idea with that?

An advance on that is bellow:

Maybe I am being slow...but you have a movie of a character moving, why aren't you just looping the movement you want. What are the five sections for?

It sounds like you are saying you want to isolate a moving character in a movie and loop the movement. Would that be right? What is your main objective?

Are you able to edit your video before you bring it in to Max? If you have access to Adobe After Effects or similar its probably easier to draw a shaped mask and have it follow your character, then you can render a video with an alpha channel and just play this in Max.

Yes, It would be, but I'm doing this as part of a larger project. The idea is to be able to track movement in a sectioned matrix (like scissors) and trigger the movement rithm from there, for this to happen live.

As for now, I'm considering a fixed movement rate happening in a movie that I can control so that I can trigger it to get the character "chasing itself" closer or farther according to a control (I'm still deciding what kind of control).

Certainly it would be way easier to do this in AE but you can't do it realtime nor reactive...

OK, think I am starting to get it now, maybe this will help you:

A simple patch that enables you to move a mask around using GL objects, you could replace jit.gl.gridshape with jit.gl.sketch to be able to draw your mask instead of using a shape.

That´s great!

Now, I only have to figure out how to make the shape a rectangle and fix its dimensions...

Thanks!