Jump to content

Roof object

Daryl Wood

Recommended Posts

Trying to develop a fairly simple roof on a house, it seems that the roof object editing is limited to using the 3d reshape tool or simply allowing gables/hips and dutch hips.

I have spent a number of hours trying to get the roof I want on a simple house and I may be bumping into the limits of the roof object tool.

I jumped over to Sketchup and modeled the whole thing in about an hour but the Sketchup import option does not import the sketchup file the way I need it to use in the VW drawing.

I have a jpg file created from the Sketchup roof model that shows what I'm trying to get the VW roof object tool to accomplish. Is VW roof object tool limited and not capable of developing the roof design as shown in my jpg file, or am I missing something?

Link to comment

Thanks Katie for the reply, I did model it with two roofs and various different iterations. I can easily model it using roof faces but it appears the dormer function does not work with roof faces, only roof objects. I think you answered my question as to VW's roof object capability. Now, all I have to figure out is how to get the roof I made in Sketchup into the VW file.



Link to comment

You can use roof objects, rather than roof faces. This will meet both the goal of the roof style along with the ability to insert dormers.

You can still manually insert dormers in roof faces. The hole needs to be cut from the roof face, the window places, walls and dormer roof created.

Link to comment

Thanks Katie, I'll keep trying. VW does not like the Sketchup roof I created. The import filter wants me to give it thickness for floors, walls and roofs so when I already have thickness to the roof, the import filter adds to what is already there. Also, it does not do well importing the dwg file version.


Link to comment

The dwg file is somewhat limited in SketchUp.

Set the roof to some thickness for the import. Once it imports, it will convert the object to a VW Roof. You can then change the thickness of the overall roof or each roof face by clicking on one of the roof handles with the pointy-hand cursor (when roof is selected).

Link to comment

Sometimes you have to resort to old fashioned geometry or trigonometry using pencil on paper, but if the roofs are not at right angles that can be beyond most of us.

It may help if you colour the roofs (ie not white) so they show better in 3D, even a different colour for each face.

Link to comment

One of the best things with VW is the ease with which you can create extremely complex roof systems using the roof object tool and roof face tool in combination with each other. Below is an example of a somewhate complex roof that if I had spent the time on a board or with a calculator trying to figure out the trig and all I would have sent to the looney bin. However, by using the roof object tool to create multiple roof objects and setting them to the desired height to achiece the look and structure I was after...then duplicating the whole thing ( if I remember I had around 23 simple roof objects) and performing a convert to (hidden) line command...then clean up the hidden line (which by the way yields all the points for hip and valley intersections) and trace over with poly's to convert to roof faces.


It is all very simple and easy to learn. There is realy no limit to the complexity you desire with the tools VW has provided.

The roof above has a base 14 pitch set on the wall plates with no overhang and a double cut 2x8 rafter and the soffit flare is a 7 pitch set at 12" overhang and stopped at the collision with the main roof plane...all roof intersections are cut correctly so that this roof in its entirety can be framed correctly and shows up in any section requiring no edit.

Total time on the roof 6 hours. And that includes time wasted staring at it.

Link to comment


When you create a complex roof using multiple roof objects they may be acceptable in a 3D render but will not properly show the valley lines in a 3D hidden line. So you must be able to find where the roof planes collide with each other and that is done by simply performing a convert to hidden line while in plan which will cut the hidden planes leaving only the visible lines where you can grab the end points of the cut lines to form the valleys. I have used this method of roof construction for nearly 17 years in the 3D cad environment...it beats using a calculator to find the angle and height of a valley or hip so I take advantage of CAD to do the math for me...much quicker.


Petri...May I suggest taking a gander out of a window sometime (that is if you have a cell with a window and I'll bet it's difficult to move around in a straight jacket..but I'm sure you can do it!) and see what types of roof structures are around you...Yes even the thatched roof of your neighbors house...I don't consider this to be too broad a statement in saying that any roof you can think up VW has the tools to visualize and document it to the field for construction.

Gable, Hip, Cross(reversed) Gable and Hip, Flat, Shed, Mansard, Pyrimad, Gambrel, Dutch Gable, Dutch Hip, Polynesian Hip, Conical,Concave or Convex Curve....

Can you think of any roof structure that VW is not capable of building or have I left any roof types out?

Link to comment


I see your point with the hidden line conversion. That is what I have been missing with VW's tool. I'm fairly new to the application but have been designing 3d CAD roofs for years and just needed to know how VW handles it.

I experimented with a few different roof objects on a test roof, dragged the roof object past what I figured was the intersecting hip/valley and ridge points using the 3d reshape tool and then used the convert to hidden line tool cutting to the intersect points. I assume this is how you do it?

It is funny I did not come across this technique in the Step By Step book or any of the online tutorials.

I appreciate your help and I think I have it now, yea!


Link to comment


I rarely use the 3D reshape tool creating roof structures...but I'm all for using whatever tool you need to get the job done.

Petri... Found this is the VW gallery... Click here to view roof By Andrew Alcantara


Click here for roof done by Danny Morales on the VW Commercial Gallery

Oh...and we use animal skins(synthetic of course for all the activists) to cover our structures here in North Cakalaki. They provide protection from the elements as well a variety of textures and colors not to mention great warrier status among the cave dwellers.

Link to comment

Daryl, I think what Pete means is that he uses Roof Planes, and edits the underlying 2d polygon using the geometry disclosed by the hidden line render in plan view. Since the underlying roof plane polygon (accessed by Ctrl + [) is by definition a plan view, this will create a roof plane with a boundary at the hip or valley you want.

Link to comment

Petri... Found this is the VW gallery...

Yes, of course. I've done some quite complex roof shapes myself, with extrusions & solid operations, some conceptual/illustrative tensile roofs with NURBS and so on. But they are not exactly easy, like just drawing a polygon and saying "let there be a roof Calatrava would be envious of".

Link to comment

I think I'm still missing something. If I have a simple gable roof with two roof planes, both on the same design layer, with a Z axis is set to 12', both have the exact same size attributes and pitch, why is it that they are not at the same ridge elevation? One of the planes is 10 1/8" below the other when I look at it in elevation. Now I know that I can adjust the Z setting up 10 1/8" in the object info box to solve the problem and bring the ridges to match, but why do I need to do that? I thought that if the design layer is set to a specific elevation, both roof planes should be relative to the design layer elevation.



Link to comment

Daryl, I think that the "z" height of a ROOF FACE is based on where the original pitch/direction line was drawn. Therefore, if you drew the line exactly at the wall line, the height should be correct, but if you drew your line somewhere else.... Two ways to get around this: 1) Use the CREATE ROOF command for the initial roof creation, then UNGROUP to end up with a series of ROOF FACES *which should all be aligned by virtue of their original method of creation), or; 2) After creating the ROOF FACES go to a straight-on view (front, left, etc) and use the ALIGN command to moved all of the selected ROOF FACES to the same height.

One other notable trick for roof creation: If the "z" values of the ROOF layer are exactly the same as the "z" values for the PLAN layer, then you can create the ROOF (object or face) right in the PLAN layer (and see how it aligns!) then, you can CUT the roof and PASTE IN PLACE in the ROOF layer and it will be exactly where you want it... HTH's

Link to comment
if you drew the line exactly at the wall line, the height should be correct, but if you drew your line somewhere else....

Or moved it afterwards. It is a little-known fact that the "pitch line" (or either of its end points) can be moved - even outside the actual roof. This is also easy to do by accident.

Link to comment

Ok, that helps alot, had no idea that the pitch line location was critical. As far as the "notable trick" option, frequently my roof objects or planes fall on a plate elevations that vary. For example, I'm trying to create a large gable dormer over a loft space that sits on 2' knee walls above the upper loft floor elevation. I have tried to set the working plane at the top of the knee walls and then create the roof polygon. Maybe the pitch line will help with this.

My understanding of time-effective roof creation is as follows:

1. Create the 2d polygons around the exterior walls for the roofs segements that fall at the same plate elevation.

2. Combine all the polygons into a single polygon and create a roof object.

3. Continue with polygons for different plate elevations and create the associated roof objects. All roof objects should be on the same design layer.

4. Adjust the roof objects for gable/hip and overhang attributes.

5. Ungroup all the roof objects.

6. Select all the resulting roof planes and covert to hidden lines which will identify intersecting point.

7. Create new polygons from the identified intersecting points. Delete the hidden lines.

8. Select the new polygons and create roof faces from them setting up all the required attributes and locating the pitch line on the wall to establish elevation.

9. General clean up if necessary and your done.

Have I got this all correct?


Link to comment

Daryl, Yes, more or less. Remember that one of the best things about VW's is that there are various different methods available to acheive the desired result. As a note, you could probably save a little time if instead of entirely deleting the first set of roof faces, you just added/subtracted surface to/from them. If you double click on a roof face (and just about any other 3d object) you can then edit (in plan, or "plane of creation" view) its underlying geometry, including ADD SURFACE, SUBTRACT SURFACE and simply stretching or reshaping using the 2d reshape tool. When you are finished just click done and you will back in the "real" world (and your roof faces will have been modified).

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...