[SOLVED] .split() is ignoring keepTop and keepBottom

[aaroncaba]

This feels like I'm making a dumb newbie mistake. I am trying to split a solid body by an infinite face and I only want to keep the top (or bottom) part. But my .split() call ignores whatever I put in for the keepTop or keepBottom parameters.

What I expect is only one body in splitPrism. What I am getting is two bodies in splitPrism.

I found the discussion at https://github.com/CadQuery/cadquery/issues/751 where they used .split(keepBottom=True) and it works as expected, but it isn't working in my code snip.

Should I be using a Workplane or other thing instead of a Face for doing the cut? How would that work?

Thanks in advance,
Aaron

import cadquery as cq

# define points in 3-D global coordinates, these all lie in a single plane
prismPts = [(1, 0, 0), (2, 1, 1), (2, 1, -1), (1, 0, 0)]

# workplane rotated to same plane as prismPts
wp = cq.Workplane("XY").workplane().transformed(offset=cq.Vector(0, 0, 0), rotate=cq.Vector(90, 45, 0))

# move prismPts to local CS
localPts = []
for p in prismPts:
    localPts.append(wp.plane.toLocalCoords(cq.Vector(p)))

# Extrude normal to the workplane
prism = wp.polyline(localPts).wire().extrude(0.25)

# make an infinite face for cutting.
ff = cq.Face.makePlane(None, None, cq.Vector(0, 0.1, 0), cq.Vector(0.2, -1, 0))

# split the prism into two, but ONLY KEEP ONE PART
splitPrism = prism.split(ff, keepBottom=False, keepTop=True)    <----This does not work

[aaroncaba]

After further digging I found the .solids() method to keep only one of the solids. I used the DirectionMinMaxSelector with the same normal vector as the face:

normal = cq.Vector(0.2,-1,0)
ff = cq.Face.makePlane(None, None, cq.Vector(0, 0.1, 0), normal)
splitPrism = prism.split(ff,  keepBottom=True).solids(cq.DirectionMinMaxSelector(normal,False))

This solved my issue and now I just keep the parts that I want.