Blend Edge Frustrations

[Cloud Hidden]

Create a 20'R Hemisphere. Create a 15'R Hemisphere, and give it a Z of 5'. Position them so they overlap by maybe 5 or 10'.

What I want is to create a 4'R fillet at the curve created by their intersection. Blend Edge just beeps and says to do that Tangents thing (done) and use a diff radius (tried). Ideas?

Thinking that maybe the the horizontal part of their intersection at z=5' created the problem (and I didn't need that blended anyway), I "Section Solids" to trim the bottom 5' off the first dome. Now they have the same bottom elevation.

This time Blend Edge "works", however it erases the larger dome and just curves the open edge of the other one.

Any insights? Any other ways you can think of to blend the curved edge of two domes when one has a different Z than the other?

[MikeB]

What version of VW are you running?

[Guest]

I got the file you sent. I've been racking my brains over it myself.

I went ahead and forwarded it to Biplab, to see if he could help out.

I'll let you know what he has to say.

[Cloud Hidden]

Thank you, Katie.

v10, Mike.

[MikeB]

quote:

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Originally posted by Cloud Hidden:

Except give the smaller one a Z different from the bigger one.

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Like this?

I did this by creating spheres, slicing them to get the hemispheres, adding solids, then filliting.

quote:

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Originally posted by Cloud Hidden:

Two followups on your drawing (and thanks for the efforts):

1. Can you create an inside shell for it? That command didn't work for me, and it was one of my fondest desires for v10;

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I don't know, I'm at work using 9.5.3. I'll try it at home tonight in 10

quote:

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Originally posted by Cloud Hidden:

2. How did you get the red lines in that pattern?

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Its the Grid Color Shader

Here's the dialogue

[ 11-15-2002, 01:25 PM: Message edited by: MikeB ]

[Guest]

And the answer is ....

You can use the fillet surface tool to place a fillet where the two surfaces intersect.

[Biplab]

If you have problem creating a shell using the shell tool, you can create the shell manually as an alternative - specially if you have only a few faces. In this case there should be 3 faces (2 spherical + 1 planar).

Here is what you do:

(1)Extract the two spherical surfaces using extract surface tool. Offset them by the shell thickness using the offset tool.

(2)Extract the planar surface using extract surface tool. Extract the bottom edges (lying on that planar surface) of the offset surfaces using Extract curve tool. Project and trim the planar surface with these curves (you may need to compose them together). The idea here is to get small planar strip of the shell.

(3) Extract the original spherical surfaces. You can add these surfaces and the offset surfaces and the planar strip surface to create the shell.

In general, using 3DPP you can use several different ways to achieve the same thing. For instance, you can create a fillet surface instead of creating a solid fillet to get the peanut shape.

[MikeB]

Is this what your after?

I think I followed your directions.

[Cloud Hidden]

Except give the smaller one a Z different from the bigger one.

I've made the "peanut shell" shape when Z=0 for both, but not via hemispheres when the Z's differ. (It's domes built on a sloping site, so they will have stepped footers.)

Now I did just have "success" by using spheres, rather than hemispheres, and then subtracting solids from the bottom. But that's some extra steps and I haven't thought through if there's a way that will bite me in the future. Hopefully not.

Two followups on your drawing (and thanks for the efforts):

1. Can you create an inside shell for it? That command didn't work for me, and it was one of my fondest desires for v10;

2. How did you get the red lines in that pattern?

[Cloud Hidden]

When I Add Solids on the two hemispheres, and make that the only selected object, the Create Fillet Surface command is disabled.

If I convert that to Nurbs and select just the two shell portions, the command is enabled, but choosing it gives the message, "Fillet surface could not be created. Try changing the fillet radius." That was for a 2', 4', and 8' R on spheres in the 20 to 30' R range.

There's no denying the drawing you posted, Mike, nor Katie's suggestion to use the same command, but I'm thus far unable to explain the above. Katie, did you successfully use that command on the sample drawing? How?

[Guest]

They need to be two seperate objects and nurbs surfaces.