Shell Solid

[Cloud Hidden]

I want an 18'R Hemisphere with a 7" thick inside shell. Seems like I should be able to use the hemisphere tool, convert to NURBS, ungroup, and use the Shell Solid tool. But that just tells me to select Tangent Faces, which is selected.

Should this tool work in this way, or in some other way?

[Cloud Hidden]

10.0.1 makes no difference. Create a sphere of any size. Nurbs. Ungroup. Shell Solid never seems to work. Any ideas? Isn't this a proper use of Shell Solid?

[Biplab]

Why are you converting to NURBS and ungrouping? The shell tool works directly on spheres and hemi-spheres. For a hemisphere select the face you want to open up and input a reasonable thickness (less than the radius if you are going inside).

For sphere the process is the same.

[Cloud Hidden]

I guess my question is, why shouldn't it work on a nurbs hemisphere? The tutorial/manual example is of a nurbs object, I believe. I regularly have spheres, intersected spheres, torii, and similar, and they are nurbs objects, or solid additions or solid subtractions, and I'd expect Shell Solid to work with all of them. But it doesn't seem to, even after the 10.x enhancements.

[Biplab]

Shell Solid process is this: If you have a solid and you select a face on the solid - the program offsets every face other than the face you selected by the shell thickness, but keeps the selected face in place. The program then subtracts the solid created by the above procedure from the original solid to create a shelled solid.

In case of a hemisphere, you select the face you want to open up (the planar face or the hemi-spherical face0 and shell it.

If you convert the hemi-sphere to NURBS - and ungroup - you get two separate NURBS surfaces. Now when you select a SINGLE NURBS Surface, the Shell Solid Tool works differently - it basically thickens the surface to create a Shell. In this case, if you select the hemi-spherical NURBS surface, it should thcikne it - but the result would be a little different. Because since there is no connection between the hemi-spherical surface and the planar surface (which it does when it is a solid hemi-sphere), the shape you would get is different. In any case, it should work using surface too - if it does not - it's a bug - I will investigate and let you know. Thanks.

[Cloud Hidden]

Thanks for the explanation and update. I look forward to the results of your experiments. To put it in context, I design air-formed (inflated) houses. They are individual spheres/ellipsoids, or combinations of those. The intersections are either simple (a sharp point where they intersect) or curved (with for example a 4' R saddle). Ideally, I can create the zero-thickness airform shape--the final inflated shape--and then give it thickness to represent the 8" of foam/concrete sprayed inside. I've had trouble with the saddle connections at times and with shell thickness regularly. I know I can create the outside shell, then create an inner surface 16" smaller (2 x 8), but when I cut holes in them for windows, doors, or artistic openings, I have to extract the edges and loft a surface to fill the gap, and it can get tedious. Searching for a quicker approach, and Shell Solid seemed to hold promise. Any insights greatly appreciated.

[Biplab]

I have found and fixed the bug in thickening a hemispherical surface. It would be available in an upcoming release.

[Andrew Bell@NV]

quote:

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Originally posted by Cloud Hidden:

I've had trouble with the saddle connections at times and with shell thickness regularly.

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You could create the thickened hemisphere via Solid Subtraction. If you often have hemispheres of the same size and thickness, I'd suggest setting up a symbol library. You might also look at using the Project and Trim Tool or Split Tool in Split By Line mode from a top view to cut the initial openings for your saddle connections, and then extract curves to get the shapes for the loft. And again, making symbols for the saddle connections where they are of common size and thickness will save you a lot of time.

[michael john williams]

Treying to create a sheel from a solid object but the shell preference box does not come up when selecting the face of the solid object.

Why is this?

The solid object is an extruded rectangle and I am on VW 11.1 standard.

[michael john williams]

In the object info box ?no selection ? locked? is displayed.

[michael john williams]

Bit disappointed no one has replied yet.

Perhaps in can not be done in the Standard version?

[mike m oz]

mjw - it works for me!

Are you clicking on the tick box after you have selected the required open face to confirm your selection?

Download and have a look at the Extracting Curves from Solids tutorial at this address http://www.nemetschek.net/3Dpowerpack/tutorials.html

BTW nurbs modelling is part of 3D Powerpack which is included in all versions of VW.

[michael john williams]

Mike

Thanks for that - the tutorials where very useful and I am going to try it on the job now!