A few methods for shortening curves by absolute distances, unlike relative when using the carve node.
Instead of cutting curves and removing points, we can shift point positions of curves along themselves.
Linear interpolation while shifting points inwards along the curve:
float shorten = chf('shorten');
float perim = primintrinsic(0, 'measuredperimeter', i@primnum);
float inset = shorten / perim;
float u = vertexprimindex(0, i@vtxnum) / (primvertexcount(0, i@primnum) - 1.0);
u = fit01(u, inset, 1.0 - inset);
vector uvw = set(u, 0.0, 0.0);
vector pos = primuv(0, 'P', i@primnum, uvw);
v@P = pos;Smooth interpolation while shifting points inwards along the curve:
float shorten = chf('shorten');
float perim = primintrinsic(0, 'measuredperimeter', i@primnum);
float inset = shorten / perim;
int pts[] = primpoints(0, i@primnum);
insert(pts, 0, pts[0]);
append(pts, pts[-1]);
vector poss[] = {};
foreach(int pt; pts){
vector pos_pt = point(0, 'P', pt);
append(poss, pos_pt);
}
float u = vertexprimindex(0, i@vtxnum) / (primvertexcount(0, i@primnum) - 1.0);
u = fit01(u, inset, 1.0 - inset);
vector pos = spline('cubic', u, poss);
v@P = pos;In a primitive wrangle we can cut curves (internally removing points and moving the last point) using <groom.h>.
#include <groom.h>
float shorten = chf('shorten');
float perim = primintrinsic(0, 'measuredperimeter', i@primnum);
adjustPrimLength(0, i@primnum, perim, perim - shorten);
