Hi

I'd like to model a surface or a solid with square facets on a slice of a sphere as shown in the attached picture.

I am not sure how to best approach this and would appreciate any help.

Thanks!

Mark

Here's a Boolean approach. I'll leave you with the tedious task for positioning each "cut" tool part around the dome.

Hi Kevin,

Sorry I don't mean to be ungrateful but that solution seems pretty close to self-flagellation to me

I was hoping for some devilishly clever trick. I know this is a real challenge.

Mark

I'll let you know if I think of a better way.

Mark,
I think you should be able to :
1. Create the dome shape
2. Drag a square block to its center and position close to top tangency
3. Extrude a custom shape that is tangent to dome and connects at end points of square (i.e 1"square then the bottom points intersect dome). Extrude 1" to complte a square shape.
4. Measure the angle distance from point to point (intersectiobs). Lets say angle is 5.4 degrees for argument sake then.
6. Create a rotational pattern with number of copies and angle at 5.4 degrees.
7. Then creat same pattern 90degrees .

Hope this makes sense. If I get time I will try to do it in reality.
Tom

I miss some info,
-Witch detail level do you want on the facets?
Do you want exact dimensional values on each facet?
If so, witch values?
-Can you use Export As STL and import?
-Will you do a 2D drawing of this or only a good looking rendering?

It should be quite simple. All you need is a piece of facetted geometry, which can be done like this:

1. add a sphere (which *is* a revolved sphere and contains the facets you want)
2. export this sphere to *.OBJ format (facetted geometry, which retains quad faces instead of triangulating them)
3. re-import this OBJ file (which still is a solid you can use boolean tools on)
4. cut the portion you need (from the sides, not top or bottom)
5. difference a smaller sphere from the rest.

Attached is a file I created using an other application (which directly supports facetted geometry, without using the ex-/import route), but in IC it should work exactly as described above :-)

Bernd

How about this one.
Dallas

I've tried the STL export/import trick but that did not produce square facets.
I'd like square facets as shown in my attached picture. This is for a rendering/appearance purposes only so I do not really need perfect dimensional accuracy but just a convincing picture at 300dpi at 8.5 x 11 inches.

Mark

I take it back, Robert - your idea worked pretty well. Thanks!
Mark

Bernd, I could not get this to work. It got reimported without well-defined facets. Thanks! Mark

Tom, I don't think this will work if I follow you correctly. Only the blocks on the centerlines of the dome would behave correctly. Thanks! Mark

Well, I just tried to to repeat what seemed to work yesterday (I was sure that I ex-/imported a sphere successfully), but today the results confirm your lack of success. Interesting enough: if I import the (OBJ) sphere I created in IronCad into FormZ, it arrives there as a perfect, facetted solid. Doing the same in IC leads to a facet part, which either has the facets required but is not a solid, or, after converting to a solid, has some triangulated facets. Not what it should be in my opinion...

Bernd

If it is only for rendering purposes, you can do this with an image and the bumps. Attached is a start of a sample....

I used the BlueGrid in the IronCAD images. Set the mapping to Spherical. Made the Bumps High.

[attachmentid=3444]

As you can see you just need to find a nice image that will produce the smooth results you want from Google Images. Some sort of sqaure grid with soft lines (easily created in Photoshop).

Let me know.
Thanks
Cary