Trimming from a solid outline

Tender Step copy 4.3dm (773.0 KB)

Look at the ‘test’ layer by itself.
I need to trim the surface on the C-plane using the x-y boundaries of the pipe. Then I will have a silhouette surface of the pipe on the C-plane; so this would look like a ribbon directly under the pipe on the C-plane. I then want to extrude the surface upward to make walls that intersect the pipe, then trim the walls with the pipe.

I know I can’t trim the surface with a solid. I’ve tried projecting the pipe to the c-plane, which works, but the result is a closed polysurface, which I can’t use to trim with. How can I get curves that represent the x-y dimensions of the pipe with which I can trim the surface. thanks, rex

Hi Rex - in Top view, run Silhouette on the pipe, then use the curve to trim the outside of the plane, also from Top.


Awesome; I was playing with silhouette, but not from the view. thanks

top view

Tender Step copy 4.3dm (777.4 KB)

Now I’m trying to trim the walls so they stop at the sides of the pipe. I also need the bottom half of the pipe trimmed by the walls. Neither trimming operation will execute. thanks, rex

These Slihouette curves will trim/split the pipe and the box.


Tender Step copy 4.3dm (652.5 KB)

I’ve made some progress. However, I cannot get boolean union to work. I have two polysurfaces that will not union together. When I show edges, I have a couple of naked edges showing on the bottom, but it doesn’t make sense to me where they’re coming from.

thanks, rex

You are trying to BooleanUnion a closed solid and an open polysurface.

Hide the upper part with the walls so you can see the base by itself.

The base is a solid with no naked edges.

Show to see the upper part.

Hide the base so you can see the upper part by itself.

The upper part is an open polysurface. It doesn’t have a bottom. The naked edges are the bottoms of the walls. Use

Cap to close the polysurface and turn it into a closed solid.

Show to see the base.

BooleanUnion to merge the upper and base together.

Thanks, I wasn’t aware you couldn’t do that. Makes sense though.

That did it. thanks!

Tender Step copy 6.3dm (984.9 KB)

Almost there, but I can’t get the two vertical fillets to booleanunion with the rest of the part. Everything else yields a closed polysurface, but the two vertical fillets at the wide end will not include in the union. rex

:smile: In the one message you say it makes sense that one cannot boolean a closed object with open surfaces and right after that you are trying to do it again?

At any rate, yes, you can boolean open and closed objects together but you need to be sure that the intersecting curve is either closed or ends up on an edge that makes sense.

In your file, when you run Intersect between the solid and two of the fillet surfaces, you get this:

In the red circle you see that the intersection curve is not closed. This makes the boolean fail.
That said, I wouldn’t recommend making fillets by boolean geometry.

Also, the fillet surfaces that you have, have a problem with the surface edges crossing each other, resulting in the ‘bow tie’ surface that you can see at the top. The fillet overshoots the top of the rounded edge because the seam ends a bit over the top. I would split the edge to fillet right at the top by snapping to the quad point there:

When you do that, you can use FilletEdge to make fillets that produce a solid.
Tender Step copy 6-wd.3dm (482.9 KB)

Thanks. What threw me off is that all the other fillets unioned in with the approach I was taking. I didn’t notice until later that these two didn’t make it. I’m still trying to get familiar with debug techniques.