VEX, PointClouds - Changing attibute data

[Whatsinaname]

In my scene, there are lots of similar objects, consisting of points.

The points have an attribute, indicating to which object they belong (object_ID).

 

If any of those points collides with another object in the scene, the pscale of those points should be set to 0.

The collision test etc works just fine, I only don't get how to set the object_ID, like:

 

A) get the object_ID for the points inside the collision volume (works)

B ) get all other objects with the same objectID and set their pscale to 0.0 (doesn't work)

 

 

Here's what I'm doing:

float sdfCheck = volumesamplefromfile(1,"surface"@P);
if(sdfCheck < 0)
{
     // change color to visually identify points inside collision volume
     @Cd = {1,0,0};
      
      //open a pointcloud and check for the object_ID value
     int handle = pcopen(0,"P",@P, 20000, 100);
     int ref_object_id;
     float target_pscale = 0.0;

     while(pciterate(handle))
     {
          pcimport(handle,"object_id", ref_object_id);

          //check if the object_id at the pointcloud point is the same as the object_id of the point inside the collision volume
         
           if(i@object_id == ref_object_id)
           {
                   // doesn't work as channel is not writable...??
                   pcexport(handle, "pscale", tgt);
                   
           }

     }
} 

pcexport doesn't seem to be the right idea in that context, but what should I be doing instead? Thanks in advance for any ideas!

Edited July 13, 2015 by Phlok

[anim]

you can use setpointattrib() if the attrib already exists. if not then as well addattrib() to initialize it first;

[anim]

you can as well use findattribvalcount()/findattribval() combo to loop through all points with certain attrib value and set their pscale instead of checking all points for matching object_id yourself