Curved Roof ?

[Alora]

How do I create a curved roof for a house?

[CipesDesign]

You will need to model it using the 3d Modeling tools. If you can give us a hint as to the exact shape you're after we may have some more detailed guidance. For example, if it is simply a barrel then you could go to a front (or side) view and draw the curved 2d shape that is appropriate, then extrude it. Also, I word of advice, from experience. Think carefully about how it will actually get built. Often this will lead you to the correct solution for modeling it in VW's (or any other software I suspect). It may also help you to avoid drawing something that simply cannot be built, or is prohibitively expensive.

[Alora]

Hi Peter,

It's a shallow curve, 10 feet above the floor at the peak. I've already drawn it in section with the round wall tool but want to see what it looks like in isometric view. I realize it will be an expensive roof to build but I am doing this house design for practice.

Alora

[Guest Wes Gardner]

Using Peter's methodology, these are simple extrudes...

[VincentCuclair]

Not so hard and not too expensive......check it out (just remember, too keep construction costs down you need too connect the bottoms of the arch)

http://www.cuclair.com/Cuclair_Arkitektur/Projekt/Sidor/Villa_Ekangen_II.html#0

Edited October 28, 2010 by Vincent C

[CipesDesign]

Nice stuff Wes and Vincent. Alora, if you already have the section then the shape already exists. All you need to do is extrude it (make sure it's "closed" and filled first, otherwise you may have trouble rendering it solid).

[CipesDesign]

PS: I have seen examples of this type of roof built from custom curved glulam rafters (purlins?).

[bcd]

Nice work Vincent, you could really do with better photos to appreciate this one.

Edited October 28, 2010 by bcd

[VincentCuclair]

Yeah I know I haven't got round to it, I do that on the side so marketing isn't so essential at present, hope to update all projects with good photos within the coming year.......or so.

Edited October 29, 2010 by Vincent C

[Alora]

Thanks for sending the examples Wes and Vincent - they are inspiring. Although I have drawn the curved roof shape in section I am not sure how to extrude it. When I click on 'extrude' I receive a message "...objects selected were locked or are illegal". Is this because I used the round wall tool to draw it? What do I do now?

[CipesDesign]

Yes, it's because it was created with the wall tool. Go to a side-on view and draw a closed polygon (you can use circles, ovals, clip surface/addsurface, etc) then extrude that....

[VincentCuclair]

Alora, here's what to do:

What you need is the cross section of the roof drawn with a closed shape that has a fill (preferably drawn in the view in which you want it extruded (ie. front view)). You then select this shape and extrude it as long as the roof is meant to be. The fill is important for showing the roof as a volume as opposed to a wireframe object when rendering later on. By dubble clicking the roof extrude you can edit the cross section shape at any time.

Try this with a square first so you become familiar with the work flow and don't spend unnecessary time drawing complicated shapes that don't extrude. Good Luck!

An alternative way would be creating 2 cylinders and subtracting these from each other and then splitting the remaining 'tube' to be left with the correct roof volume.

Edited October 30, 2010 by Vincent C

[islandmon]

Compared to simplistic CAD mass modeling... all roofs require structure .. and that's half the challenge.. isn't this why we all adore our VW : )

Curved roofs are especially gratifying ... as there are so many ways to make the arcs... ( materials & assembly systems ).

1) Begin with the exact math based on the units of minimum assembly.

2) Determine the frequency of subdivision / segmentation

3) Design the sectional chord factors based on proportional span / loading / moments, etc.

4) Model the arc truss modules and circumferential foundation elements using symbols.

5) Model the roof decking using symbols

6) Don't forget to compensation for the helical, longitudinal, torsional & shear stresses.

Image of a 'pre-engineered' curve-formed galvalume panel structure.. modeled per the fabricator's specs :

[img:left]http://www.fractalnet.org/gallery2/v/ARCH/AEC_Projects/JBK5137_001/JBK5137_A-PRE-2.jpg.html?g2_imageViewsIndex=1[/img]

[Guest Wes Gardner]

Here are three easy steps to create a curved roof...

First draw on arc in FRONT VIEW.

Switch to Left Isometric so you can see and then EXTRUDE the arc the depth you need

Now SHELL the surface to whatever thickness you need

[Guest Wes Gardner]

Or...

[Alora]

Wes - Thanks for the step by step instructions. However, I only got as far as step 2 with lopsided results i.e. the 2D roof is floating high above at an angle different than the left sided isometric view of the house. Where is the SHELL toollocated? How do I attach the roof to the walls?

How do I attach my file to this email?

[Alora]

Here's what finally worked thanks to technical help from my distributor at Resolve Software Solutions Inc.:

1. Select front building elevation.

2. Make an arc representing the outside curve.

3. Make a smaller arc representing the inside curve.

4. Both arcs have no fill.

5. Draw and 'snap' lines to close the arcs at both ends.

6. Select both arcs and both lines and choose Compose from the Modify menu.

7. Fill in the polyline object.

8. Extrude polyline to create curved roof.

9. Locate the roof on top of front elevation.

10.Select isometric view and viola - a building with a curved roof!

[CipesDesign]

Alora, Glad they were able to help and glad it finally worked for you. How about attaching an image of the finished roof??

[Alora]

Peter, The building is not quite finished yet but I will send it when it is. Question is - how do I attach the image?

[CipesDesign]

To attach an image, click on "Switch to Full Reply Screen" (below) then click on the "File Manager" link. The rest should (hopefully) be self-explanatory.