Using a SOP Solver to delete points that will enter a group

[vfxhound]

Hi guys, a friend was asking if he had some moving points and for example there's a group by bounding box, so some points enter the group for a few frames. Is there a way to delete those points from the entire sequence? 

I was wondering the same thing myself, so I gave it a go using a SOP Solver. Check out the example file.

delete_red.hipnc

[3dome]

//point wrangle

if (@group_red == 1)

{
    removepoint(0, @ptnum);
}

 

 

 

 

Edited July 22, 2016 by 3dome

[vfxhound]

Yes, but he wants to delete them (or color them) before they enter the group, like this example file

delete_red3.hipnc

[3dome]

so they already should be deleted in the first frame? based on them entering the bounding box later?

In your file, enable delete_red_points, the result at OUT_WITH_SOLVER is what you want to achieve?

 

if yeah, then point wrangle with
if(@P.y <= 1.3) {removepoint(0, @ptnum)}

1.3 is half the height of your bounding volume

use expression to make it procedural