Fabric Roof

I'm trying to produce a model of this building and am unsure how to do the roof any ideas? I have a line drawing of the elevation and the model so far, but here is a picture of what I am trying to produce. Can I only post one attachment per new topic? Tim

you can post as many as you need to !

Check out the " Need Help " post from Manos, two threads down .. sounds just like your question.

<http://www.sketch3d.com/forum/read.php?f=4&i=13253&t=13253>

Tim;

As Joe says, you can post as many attachments as you like, just 'Reply' to your own message and add another post, and so on.

Prof Bob

Tim:

Here is a model/tutorial that Bryce from SketchUp put together for me a while back for a street lamp base that I was trying to build. In this example the geometry is different betweeen the base and top and there is some 'sculpting' going on which is somewhat similiar to the canopy that you are trying to build with a square at the bottom and a circle at the top with a convex surface connecting them.

Sorry I haven't come up with a solution (yet, I'll sleep on it) but perhaps this attachment might get you or others to the next step.

Mike White

Lamp_base_example.skp

Tim;

While this is not exact, would this type of design work? If so, I can tell you how I did it.

Prof Bob

Prof Bob:

Looks pretty slick, can you give us a quick overview.

Mike

Spot on Prof Bob, I'm with Mike, it does look pretty slick, an overview would be great!

Tim

Okay, here it is. Download the file and extract it. I zipped it because I'm on a Mac and sometimes Windows users can't open a Mac file (unless that has been corrected in this release of SU). I would recommend that you don't resize the window unless necessary since doing so might mess up the text.

Anyway, once the file is open, you should find yourself on Page One. Step through each page sequentially (there are 14 of 'em), and you will be presented with a step-by-step procedure and brief explanation.

My technique may not be the best way to do this, but it does work. Be assured that it looks more complicated than it really is (although it is a bit time-consuming due to the need to create each polygon of the 'skin' separately). If the roof had been circular, it all would have all been much easier, but since each arc-rib is different, the ribs can not be co-planar and necessitate some hand-work. Maybe others have a better suggestion for doing this. Meanwhile, have fun while you are recovering from being stuffed by your turkey (assuming you are in the States, that is).

Hope this helps,

Prof Bob

canvasTop.skp

Excellent Bob; I was working on something similar, dome by rotating a profile. It isn't annotated yet so here's the instructions to go with the skp. Draw a profile from the top diagonally to one of the corners of the square.

Rotate it in an array to get a quadrant of them.

Draw a line joining the two end pieces - this will form the top edge of the square.

Extend lines up from this to cut off the excess.

Use the Move tool to lower the ends of the cut lines down to the straight edge.

Get rid of what you don't need and start filling in the faces.

When you've done the entire quadrant Rotate/Array it into the full shape.

tentroof.skp

Tim,

Here's the proper one. The geometry involved in this little exercise is surprisingly tricky. I tried all kinds of different methods, including a stack of circles, getting progressively larger - then changing the number of segments by increments of 4, from 24 at the top to 4 at the base. (it doesn't work) :-)

tentroof2.skp

Excellent tutorial Bob ..... but again I would expect nothing less :-)

Mike

Another approach, using autofold with move - very quick to do.

Paul

quicktent.skp

That's clever Paul. I thought that there must be some way of using autofold, but I couldn't figure it.I'm also surprised at how much the Smooth function manages to round off what are, essentially, fairly sharp corners.

I used Autofold initially, then section tool and scale tool. Didn't 'ardly 'ave to draw nuffink. ;-)

Grant

skin.skp

Volcanoes! now there's a new use for SU. ;-)

Many thanks to all of you for your help, a good program is made great with a forum of this calibre. I hope to reciprocate some day soon.

Regards

Tim

Leave it to Grant, 'King of the Section-Cut,' to come up with such a clever solution.... :-)

Prof Bob

Elegant solution Grant. Now all that's needed is some exploding lava for your volcano ;-)

Mike

BrianBtent-bb3.skp

Thanks

You can tweek the finished article (and as you go) by scaling each level about its centre. The top has a currently slightly larger diameter than the original request but you get the principal. Its a shame the slide show doesn't organically grow but that would be hard work!

BrianB