BUG: Project to cplane does not flatten curves

Rhino Rhino for Windows
1

projecttocplanecrazy.3dm (211.0 KB)

I believe results should be just lines.

2

curves are duplicated in your file - maybe update it so others don t need to worry about.

(1) workaround:
_pointsOn
_selPt
_setPt (Z=0)

(seLpt and seTpt)

(2)another workaround
_explode
_projectToCplane
_join

only the first and last curve (in y-direction) don t work on V8 / WIP on Mac.

EDIT:
(3) workaround - 3
Gumball-Scale to 0 in z-Direciton and move to 0

kind regards - tom

3

Hi Ivan -

It looks like planar polycurves consisting of arcs are not projected to the CPlane
→ RH-77924 ProjectToCPlane: Polycurves consisting of arcs project to self
-wim

4

What’s interesting is that it’s perfectly capable of transforming all of the curves via a script…

import rhinoscriptsyntax as rs
import Rhino
obj_ids=rs.GetObjects("Select curves to project to CPlane",4,preselect=True)
if obj_ids:
    xform=rs.XformPlanarProjection(Rhino.Geometry.Plane.WorldXY)
    rs.TransformObjects(obj_ids,xform)

Note also that the problem is in both V7 and V8…