Cylinder surface incorrect Axis Direction

[redsk]

Hi, I'm implementing some "drilling" for a project of mine and therefore I need to detect holes in parts.

The orientation returned by face.wrapped.TShape().Surface().Axis().Direction().Coord() seems to be correct in one case of the cases (c below) and incorrect in others (a and b).

In fact, for c the direction axis is parallel to x (correct) while for a and b it is parallel to z (wrong).

Why is this so?

importcadqueryascqfromdataclassesimportdataclass@dataclassclassHole(): radius: floatcenter: cq.cq.VectorLikedirection: cq.cq.VectorLikedeffind_holes(p: cq.Workplane, hole_size, tolerance=0.001): holes= [] forfinp.faces(): if (f.geomType() =='CYLINDER'): surface=f.wrapped.TShape().Surface() radius=surface.Radius() ifabs(radius-hole_size) <tolerance: direction=surface.Axis().Direction().Coord() center=f.CenterOfBoundBox() holes.append(Hole(radius, center, direction)) returnholesdefget_solid(): return ( cq.Workplane("YZ") .moveTo(0, 0) .lineTo(0, 10) .lineTo(10, 10) .lineTo(10, 0) .close() .extrude(2, both=True) ) a= ( get_solid() .workplane(2) .pushPoints([(5, 5)]) .hole(2) ) b= ( get_solid() .pushPoints([(5, 5)]) .cylinder(4, 1, combine='cut') ) c= ( get_solid() .pushPoints([(5, 5)]) .circle(1) .cutThruAll() ) deflist_holes(pl): holes=find_holes(pl, 1) forhinholes: print(h) print("holes in a:") list_holes(a) print("\nholes in b:") list_holes(b) print("\nholes in c:") list_holes(c)

Output:

holes in a: Hole(radius=1.0, center=Vector: (0.0, 5.0, 5.0), direction=(0.0, 0.0, -1.0)) holes in b: Hole(radius=1.0, center=Vector: (0.0, 5.0, 5.0), direction=(0.0, 0.0, 1.0)) holes in c: Hole(radius=1.0, center=Vector: (0.0, 5.0, 5.0), direction=(-1.0, 0.0, 0.0)) 

[lorenzncode]

Why is this so?

The shapes also have Location. It looks like this low level code did not consider it.

Try without the low level OCCT.

importcadqueryascqa= ( cq.Workplane("YZ") .moveTo(0, 0) .lineTo(0, 10) .lineTo(10, 10) .lineTo(10, 0) .close() .extrude(2, both=True) ) a=a.workplane(2).pushPoints([(5, 5)]).hole(2) center_cyl=a.faces("%CYLINDER").val().Center() edge1=a.faces("%CYLINDER").edges("%CIRCLE").val() radius_cyl=edge1.radius() normal_cyl=edge1.normal()

[redsk]

The shapes also have Location. It looks like this low level code did not consider it.

Try without the low level OCCT.

Mine was just a minimal example, but how do I find the normal and radius in this case?

rod= ( cq.Workplane("XY") .cylinder(30, 10) .transformed(rotate=(90, 0, 0)) .pushPoints([(0, 0)]) .cylinder(30, 5, combine='cut') )

Here the edges are not CIRCLE, they are BSPLINE, and they don't have the normal() method.

[adam-urbanczyk]

Your question does not seem to be related to the original question. Likely an x/y problem, maybe start with describing the use case.

I'm guessing that you are actually interested in faces, so:

1. Select the face of interest f=rod.faces(...).val()
2. Use normalAt() for whatever location that is of interest
3. Use _geomAdaptor().Radius() if applicable

[redsk]

Thanks for your answer.

_geomAdaptor().Radius() is what I needed for the radius.

Regarding the normal, I'm not sure how to use normalAt() for this case. Let's say I have this rod

rod= ( cq.Workplane("XY") .cylinder(30, 10) .transformed(rotate=(90, 0, 0)) .pushPoints([(0, 0)]) .cylinder(30, 5, combine='cut') )

and I want to find the axis of the "hole" (which in this case, is the y axis).

The face rod.faces("%CYLINDER")[1].val() is highlighted in the figure, I'd like to get the axis of the cylindrical surface, not sure how normalAt() can help me here.

[lorenzncode]

I'd like to get the axis of the cylindrical surface,

You could find it from the seam edge:

rod.faces("%CYLINDER")[1].edges("%LINE").val().tangentAt(0)

[adam-urbanczyk]

This is not an issue anymore, converting to a discussion.