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trim a sphere?


GISdude

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I tried to trim a sphere, but no 3d command for such a thing. No "valid edge" to grab the sphere by? I placed a 3dpolyline "thru" the sphere but no go.

 

I'm just getting into the 3d realm...

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SLICE is the 3D equivalent of the 2D TRIM command.

Read the mid command commandline prompts carefully, and you will see that there are lots of available options.

Spend a few minutes going through the tools available on the SOLID EDITING toolbar or Panel on the ribbon, and things will quickly start to make a lot more sense.

I tend to favor an isometric view when modeling, as you can better see what is going on, although were I aligning a SLICE I would use an orthogonal view, and then check it in isometric.

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Another option would be to create a box, larger than your sphere. Move the box so that it covers the area you want to remove from the sphere and then use the SUBTRACT command.

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+1 to Cad64

 

Yeah, I like the boolean operations. :P You can create some really interesting and complex shapes using simple standard primitives and the Union, Subtract and Intersect commands. To GISdude, I recommend spending a little time trying out all of the techniques and commands mentioned in this thread. They are all very useful and necessary to know and understand if you're going to be doing any amount of 3D work.

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Yeah, I like the boolean operations. :P You can create some really interesting and complex shapes using simple standard primitives and the Union, Subtract and Intersect commands. To GISdude, I recommend spending a little time trying out all of the techniques and commands mentioned in this thread. They are all very useful and necessary to know and understand if you're going to be doing any amount of 3D work.

 

I like INTERSECT a lot, it helps generating some pretty interesting shapes.

Come to think of it INTERFERE is also pretty cool.

I haven't used SHELL very much, had never really understood it until JD talked it up in a thread, it is pretty cool, though I seldom have need of it.

Be that as it may, it is still a potentially useful command, and can be much easier and quicker than creating two concentric models in order to use the SUBTRACT command in certain circumstances..

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Wow! Who knew? j/k.

 

Yeah, I'm all about learning and trying new stuff. It's too bad I'm on Autocad Map3d (I'm a GIS nerd by heart), but a lot of the commands are there.

 

Many thx,

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Ok, I've created a region for my cube (in order to subtract), but the sphere won't create. "a closed boundary cannot be determined." If I have a SPHERE, by definition that's a closed boundary, right?

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A SPHERE is by definition a 3D Solid, as is a CUBE. A REGION is flat, and so 2D. In order to be eligible for use of the SUBTRACT command you can use PRESSPULL or EXTRUDE on that region, to create a 3D Solid. Try PRESSPULL, as it is by far the easier. Not that EXTRUDE is difficult, but PRESSPULL is a newer and more clever command, in other situations, as it can be used to generate or pierce a volume. When modeling, I pefer using an Isometric view.

 

If you watch this short video tutorial, it will be really easy to understand the difference, and it will really get your MODELING juices flowing.

 

http://www.cadtutor.net/tutorials/autocad/extrude-and-press-pull/ :)

 

Patrick has pointed out that REGIONS are eligible for the BOOLEAN commands too, but that the interaction of 2D & 3D objects is not. :beer:

Edited by Dadgad
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@Dadgad,

 

 

Actually you can perform Boolean operations on regions , but not a solid and a region.

 

Thanks Patrick, I didn't know that, never use Regions. :beer:

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Wow! Who knew? j/k.

 

... It's too bad I'm on Autocad Map3d, but a lot of the commands are there.

 

Many thx,

 

I don't know what this means? Map3D runs on top of vanilla AutoCAD - so all of the commands are there - simply need to start from vanilla AutoCAD profile.

 

You should have something like this for starting vanilla AutoCAD. If not, post back for instructions on creating custom vanilla profile.

vanilla.png

(Look under Map3D rather than Civil3D.)

Edited by JD Mather
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Thanks Patrick, I didn't know that, never use Regions. :beer:

 

 

You're welcome Dadgad. Always glad to drop a little knowledge on those that have already accumulated so much of it. :beer:

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