I was playing with a tutorial “How to Stay Procedural in Houdini with VEX”.
https://www.sidefx.com/tutorials/how-to-stay-procedural-in-houdini-with-vex/ [www.sidefx.com]



I decided to try to extrude the polygons that share a center point on each side of the created object.

Essentially, I want to add each polygon that has a center point in common to a group, so I can extrude the group. I can create a group of points that are near a single point.

The key thing I need to figure out is how to use vex to select a polygon.

This is the code from the tutorial. I successfully created a point group, but I need create polygon groups to extrude. Note that I will only create one polygon group for each geometries sides.

float search_radius = ch(“sr”);
string groupname = “circlePoints”;

for(int i=0; i<npoints(1); i++)
{
vector pos = point(1,“P”,i);

int pts = nearpoints(0,pos,search_radius);

float avgDist=0, dist=0;
vector myPos, dir;

foreach(int pt;pts)
{
myPos = point(0,“P”,pt);
dist = distance(pos, myPos);
if(dist<search_radius/2) removevalue(pts, pt);
}

//printf(“%d\n”,len(pts));

foreach(int pt;pts)
{
myPos = point(0,“P”,pt);
dist = distance(pos,myPos);

avgDist += dist;
}

avgDist /= len(pts);

foreach(int pt;pts)
{
myPos = point(0,“P”,pt);
dir = normalize(myPos-pos);

myPos = pos;
myPos += dir*avgDist;

setpointattrib(0,“P”,pt,myPos,“set”);
setpointgroup(0,“circlePts”,pt,1);
}
}


Brad Carvey