Dome

[Clara]

Hey Guys!

What's the best ways to build a dome? I tried lathe and also building a half sphere flipping normals but it's a mess. I will use the dome for int and ext. views so it has to be visible on both sides. Thanks! And Happy New Year!

miti

[Jason Matthews]

I know how to build one with cad. If you can use 3d cad I can tell you how.

[Clara]

Unfortunately I don't have AutoCAD here...just Viz. It's killing me because I know it should be a straightforward thing...if I remember correctly it was so much easier with Form-z!

Thanks anyways:)

[Clara]

I subtracted (Boolean) a smaller sphere from a larger sphere and obtained a dome. Does any one know a different way?

[quizzy]

a geosphere + normal modifier [flip normals] + FFD2x2 modifier[to flatten it a little]

[tcorbett]

To build this quickly, create the cross-section of your dome.

 

Using the shape tools, build a donut shape with the preferred width. (2 concurrent circles will also work.)

 

Build a rectangle that intersects the donut. (though really any two lines will do.)

 

Convert the donut to an editable spline, attach the rectangle, trim away the extraneous lines. Don't forget to weld your vertices.

 

 

Now you have your cross section shape. Just apply the lathe modifier, and you have a dome (seen here as a half dome to show both sides.)

 

 

Since your built the cross section, you can change your parameters with interpolation steps, number of segments in the lathe, or even experiment with lofting it about different shapes.

 

Good luck!

[Clara]

Thank you so much for the wealth of info!

A little more complex that what I imagined...makes me feel better about my newbie question. You guys are amazing...the graphics even!!I am impressed:)

[Clara]

Dear Tom,

 

I followed your instructions and I get a dome whose inside is not visible (the outside is fine) I tried different variations on the instructions and I still get the same results. I either get the invisible inside or a dome that is a shell inside a shell.

Maybe I skipped some steps? I used the Attach button under the Vertex (In the Editable Spline dialog box),attached the rectangle, trimmed with the trim button under the Spline, trimmed so to get a closed double arch. I also tried leaving it open on the top, and also flipping the normals. I am really stubborn and want to see where I went wrong!!!

Thanks!!

[Clara]

Tom-

Disregard the last...I was using a "quarter"cross section (90 deg. arch) thinking it would revolve 360 forming the dome. When I used the full cross section (180 deg arch)with one side closed everything worked. I am slow today...

Thank you so much for the time/input!!

CGArchist

[Ted Boardman]

>>What's the best ways to build a dome?

 

Miti,

 

I've got a tutorial on my site http://www.tbmax.com in the Tutorial Links section that is a very flexible technique for all sorts of domes. Use your imagination.

 

Ted

[tcorbett]

CGArchist-

 

Glad to hear you were able to get your desired results. A quick note on why you might have only seen a one-sided dome:

 

When you trim those splines, they are still treated as seperate elements. Until you select each vertex and click the "Weld" button, the surfaces created by the two curves will have the SAME surface normal direction.

 

There is a long explanation on why these work this way, and how this relates to how VIZ interprets the order of the vertices, but let's just say you had two surfaces facing "up". If you look at an "up" facing dome from underneath, it will appear invisible. Welding and closing your shapes is the best way to ensure against this.