Houdini-and-Chill

In case anybody is interested: I adapted the adjustPrimLength from groom.h to work in the other direction: “`void adjustPrimLengthInv(const int geo, prim; const float currentlength, targetlength) { float diff = targetlength – currentlength; int points[] = primpoints(geo, prim); if(diff < 0) { vector lastpos = 0; float length = 0; int numpt = len(points); for(int idx = numpt-1; idx >= 0; idx–) { int pt = points[idx]; vector pos = point(geo, “P”, pt); if(idx < numpt-1) { float seglength = distance(pos, lastpos); if(length+seglength > targetlength) { float frac = (targetlength-length)/seglength;
vector newpos = lerp(lastpos, pos, frac); setpointattrib(0, ‘P’, pt, newpos, ‘set’); for(int i=idx-1; i>=0; i–) { removepoint(geo, points[i]); }
break; }
length += seglength; }
lastpos = pos; } } }“`

So between the normal version and this one I can scale polylines smoothly from both sides.

Oh and I removed the extension part, I never want the lines to become longer. So below is the modified and simplified standard version:

“`void adjustPrimLength(const int geo, prim; const float currentlength, targetlength) { float diff = targetlength – currentlength; int points[] = primpoints(geo, prim); if(diff < 0) { vector lastpos = 0; float length = 0; foreach(int idx; int pt; points) { vector pos = point(geo, "P", pt); if(idx > 0) { float seglength = distance(pos, lastpos);
if(length+seglength > targetlength) { float frac = (targetlength-length)/seglength;
vector newpos = lerp(lastpos, pos, frac);
int ptnum = addpoint(geo, newpos);
for(int i=idx; i

Just put it in a primitive wrangle, grab your currentlength with: `float currentlength = primintrinsic(0, ‘measuredperimeter’, @primnum);` and cut away… 🙂

Oh and this is in actual lengths, so if you want to cut away half your line, targetlength would be currentlength * 0.5…

I love doing all this in a wrangle since it’s more flexible than carve