How can you snap to a point of solid and line intersection?

[Anonymous]

Hello, I need some help since I can't figure out a solution for a seemingly simple problem.

I have a solid sphere and multiple lines going through it and I need to snap some objects like arcs to the points of intersection between the line and solid sphere. However I didn't find any type of a solution for this.

More to that - if I change visual style of a solid to X-ray - I can actually see where the intersection occurs since lines change color when they go inside the sphere.

Could you please help me?

[SEANT61 · Accepted solution]

One method would be to use the IMPRINT command, Select the solid, then the line - choose No for "Delete the source object [Yes/No]"

Snap to the Solid/Line intersection with the  3dosnap-Vertex.

[Anonymous]

Set your UCS to the z-axis to one of the lines (UCS ZAxis) and create a small cylinder along the line. Copy the sphere in place. Subtract the sphere from the cylinder. Repeat as needed and you can snap to the end points of the cylinder. The smaller the cylinder the more precise the end points. In some cases you might get a center point you can snap to or a mid between two point of the cylinder end.

[Anonymous]

While I did achieve my initial goal, I did it in completely different way, because of the time pressure, but your solution is exactly what I was looking for. Thank you, I learned a new important skill today.

May your lines be precise and never overshoot the intersections.

[Anonymous]

Hmmm, I must be doing something wrong - unless this method is not valid for R2015

[SEANT61]

Maybe it doesn't.  If you imprint a line onto a sphere,  that penetrates the surface, and explode the sphere, does it leave a point at the intersection.  Similar to what I did here:

[Anonymous]

I don't know about 2015 - definitely works in 2016.

1. I type imprint, hit enter

2. Select solid by clicking

3. Select line by clicking

4. Click "no" in the command line.

Nothing visually will change and your command line should still ask you to select an object to imprint.

5. Hit esc.

But now your point of intersection is available to snap. At least in 2016...

[Kent1Cooper]

Another solution of a somewhat more "ordinary" nature:

UCS command;

  CENter Osnap to center of Sphere for origin;

  Osnap to any point on the Line for point on X axis;

  Osnap to any other point on the Line for point on XY plane.

CIRCLE centered at [current-UCS's] 0,0,0 and with same radius as Sphere.

That Circle intersects the Line  at the place(s) where it hits the surface of the Sphere, and ordinary INTersection Osnap will lock onto them.

[j.palmeL29YX]

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@Anonymous wrote:

Hmmm, I must be doing something wrong - unless this method is not valid for R2015

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FYI: In ACAD 2015 it works too, just tested. Check if you do the correct steps ...

cadder

[Anonymous]

Yeah, I followed the identical steps. But I was working in 2d wireframe I'll try in a different visual style.

[Anonymous]

That is similar to what I did originally however if you have to attach 100-ish elements to a surface (before mirroring them) that becomes a nightmare... Even though it gives you a point with the same coordinates as the desired point of the solid's surface - it isn't "related" to solid. And things get way more complicated if your solid is not a perfect geometric figure (a curved asymmetric shape for example)

[Anonymous]

That was it - worked in conceptual.

[Anonymous]

Well it does work in 2D Wireframe, but you need to slide the cursor along the line until it picks up the 3D Vertex.

[j.palmeL29YX]

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@Kent1Cooper wrote:

Another solution of a somewhat more "ordinary" nature:

.

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The biggest advantage (for me) of the solution posted by @SEANT61 - it works at any solid (also freeform or other irregular form). All my thumbs up!

cadder