Intersecting a cylinder with a plane

[[Je...]]

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Hello.

I have a basic geometry question that has likely been asked on this forum, but I couldn't find the answer yet.

Why does Calypso not allow construction of the shell of a cylinder with a plane, which would result in a line (or point if a third feature were referenced)?

I know that we can use circles and lines to do this, but why does this not work on a cylinder and a plane? Thanks.
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[[Ri...]]

Yes. I agree. Please add this to the MyVoice.

[[Ri...]]

I am not sure what version you are using, but in v2022, I have no issue doing what you want, and I know as far back as v2016 we have programs doing this.

Your Feature Icon makes me think it's some type of curve.

[[Ri...]]

Rick, I think you must be mistaken, but the Intersection tool will only ever intersect the axis of a Plane and Cylinder, so if the axis doesn't intersect, then it will not calculate where the two surfaces intersect. The Shell command is just so it will calculate the diameter where the axis intersects.

Jeff, there is somewhat of a work around where you create a Perpendicular where the Cylinder is Feature 1 and the Plane is Feature 2. Then you can create an Intersection between the Perpendicular and the Cylinder. At least better than doing a bunch of circles. Unfortunately it will only give you a point though.

[[Da...]]

I think the result would be an ellipse and not a line.

[[Ma...]]

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My thoughts exactly. Plane intersection with a cone shell would yield a hyperbola.

[[Je...]]

Thanks for the thoughts on geometry of the intersection. I would like Calypso to support this type of construction regardless of the resultant geometry. Perhaps the feature window could have toggle switches like it does for "result 1, result 2, etc." for line and point intersections.

And just to nerd this out a bit more: The intersection of a cylinder's lateral surface to a plane is usually an open or closed curve but can be a number of geometry types:

🤓 If the plane cuts the cylinder exactly perpendicular to the axis, it would result in a circle.

🤓 If the plane intersects the cylinder at an angle not perpendicular to the cylinder's axis, the intersection is an ellipse.

🤓 If the plane is parallel to the slant height (an imaginary line running diagonally along the curved surface) of the cylinder, the intersection is a parabola.

🤓 If the plane intersects both halves of the cylinder but is not perpendicular to the axis and is not parallel to an element, the intersection is a hyperbola. This typically occurs when the cutting plane is steeply angled against the cylinder's axis.

🤓 If the plane just grazes the cylinder, the intersection can be a pair of parallel lines (if the plane touches both open ends) or a single line (if it touches along one generatrix of the cylinder.

[[Ri...]]

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You are correct, I was thinking of shell.