Jump to content

joining roof faces

Recommended Posts

  • Replies 51
  • Created
  • Last Reply

Top Posters In This Topic

If you created the roof using the "Create Roof" command then all the hips, valleys, whatever will be "joined" automatically (as they are all part of the same object). But if you're using the "Roof Face" command then you need to trim (or extend) each plane to meet the others. If they are all the same pitch then it is really simple: go to top/plan view and make sure all the angles are 45's. If there is more than one pitch then you either need to do the math, or fake it, but in either case make sure that the faces touch each other in plan.

Link to comment

Thanks, I made the gable in "create roof" and the hip in "roof faces". I guess I can fake it, but I thought maybe there was a "join command" that would connect the two types. Alternately, I redrew it all with one "create roof" command, and I"m now trying to move roof handle points to configure both the gable and hip shape out, but it's not easy.

Link to comment


Using the Roof Object to build your base roof is a good way to begin a complex roof structure, however you will probably need to move to roof faces to refine the final roof. I guess if you are comfortable with "faking it" you can get by with a roof plan in 2d but if you want to build the 3d model so that it is accurate than you have to get a little more intense with VW....which will let you get as complex as you want.

I usually start with the roof object to build my massing models...then once I get close I will destroy them by modifying to hidden lines...then use the hidden lines to rebuild the roof in 2d polys. This will look good for a plan view but then change the polys to roof faces is what builds the roof model in 3d...takes more time but once you get the hang of it roof modeling is easy.

You're on the right track if you are taking the handles and moving them to trim the planes together. Practice...trial and error will make you get better.

Below you will find a roof (it's not done yet) but it has a total of 98 seperate roof faces...58 are 6/12 and 40 are 12/12....it took around 12 hours to get this far. Took a long time but the contractor will have no problem visualizing the structure.



I really like the potential that VW provides to allow a real time 3d model to visualize and communicate to the field.

Pete A.

Link to comment

Hi Ruth,

Pete's techniques here I believe are the best for forming complex roofs in VW. They work, just time consuming.

Maybe in a future release, the VW engineers will provide us a tool to quickly ID the intersect points or to at least go ahead and move the face edge to the intersecting point rather than have their users spend so much time with conversion and hidden line tools.

One technique that was told to me that seemed to work good is to modify/convert/convert copy to lines. That way you don't distroy the roof face objects. However, the created lines lie under the roof faces and are not visible until you either move the roof faces or assign them to another class and turn them off, or assign the copy lines to different class and then activate the line class... easy right?

Good luck,

Link to comment
  • 3 weeks later...

When you convert the roof to lines as Peter suggests (I generally convert a copy to lines and edit my roof faces, rather than do total reconstruction), you will see that there is no line at some valleys. But you can construct that line based on the other lines you can see. Then you can correctly edit the shape of the roof face polygon.

Link to comment

Sounds good! DesignExpress is famous for developing useful tools. Pity they are not based in India.

I've "conceptualized" this kind of functionality for years, but never even attempted write the script. I seem to recall that capturing the "tilt control line" was not possible with VectorScript, but the bravest of Gauls of course master C++.

Link to comment

I don't think it's hard to made such a tool for those who have still VW 11.5, because its just math. when you have the equation of a line and that of a plane, you can search the intersection point. and that's what the tools does, you select an edge, then the two edges that it connects to are lines. then the intersection of these lines with the plane (the other roof face) is calculated. and if you draw the selected edge from point one to point two, you'll have your connection! almost every tool use math!

Link to comment

Instead of getting into hidden lines and things, why not just take the original Roof Object and ungroup it? This reduces it to its component Roof Faces, which can easily be modified in plan. (of course if desired a copy of the original roof object can be made to preserve it).

If you draw a shape, such as a polygon, that overlaps a roof face, you can simply add it to or subtract it from the roof face by selecting the shape and the roof face and using the "Add Surface" or "Subtract Surface" commands. You can also double-click on the roof face to get to its base polygon which can be modified using the 2D reshape tool.

Where roofs of different pitches intersect at valleys and hips, the angle of the line in plan that represents the valley or hip can easily be derived from the two pitches: a 7:12 roof intersecting a 9:12 roof will have an intersection that in plan is represented by a 7:9 line, where 7 is the leg running up the 9:12 roof, and 9 is the leg running up the 7:12 roof.

Link to comment
Instead of getting into hidden lines and things, why not just take the original Roof Object and ungroup it?

Will, if you have a roof object, you do have to start by ungrouping. But the point of doing the hidden line conversion is that you don't have to do the math to find intersection lines - VW does it for you. Typically, this is done to determine the line of a valley. Though the valley is not shown in a hidden line rendering, its two endpoints are evident in the other lines displayed (you just have to create a line with two clicks).

Re: Robert's comment, I believe he is saying that once you have one of your roof faces defined with the correct line of intersection, you can use it to edit the other intersecting roof face by clipping. This shortens the process by a few steps - thanks for that tip, Robert, I wasn't aware that the "clip" command would do this.

I also find that you can clip a roof face directly with a 2d polygon! This makes it possible to avoid using the 2d edit window altogether.

Link to comment

I second LarryAZ's wish. Let the program do the maths and give us the result.

The clipping and adding faces works if you understand the roof geometry. It starts getting complicated and more difficult though when you have roof faces at different pitches and/or pitching heights. This is where LarryAZ's capability would be invaluable.

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...