# Roof with different eave heights - how to?

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At our office we're trying to shape a 2-sloped roof with different eave heights (attached image & vwx file)... with no success.

The "Roof face" command is not suitable starting from a polyline/polygon with four vertexes each with a different height; as well as rotating a roof face on a plane different than the layer plane is also not allowed.

Any suggestion/help? Since we're working in an advance stage of design, we're not that keen on using/switching to auto-hybrid objects: it would mean loosing all roof/slab/wall constrains (components, etc.) plus we're a kind of scared by the interaction among auto-hybrid and wall peaks.

Thanks in advance for any help/suggestion.

roof face - different eave heights.vwx

You can't create it from 1 roof face alone, I think the best way will be to make 2 roof faces

If the roof is one plane, you can  make the roof face tool work so long as you compute the actual angle of the slope of the roof relative to horizontal. With a bi-directional roof pitch the slope arrow for the roof polygon will need to be at an angle rather than perpendicular to the polygon perimeter.  You can calculate the angle using trigonometry (or a lot of trial and error)...

Edited by Taproot

thanks Taproot, I see the point, I’ll give it a try: I guess I could use geometry rather than trigonometry, although not that sure about it.

Diego: nope, not that true, but thanks for your kind reply: the issue is not a geometrical issue (the roof is one plane, with 3+ vertexes all on the same plane), but it is related to the “roof face” tool: the best would be having the possibility to create a bidirectional roof pitch, e.g. generating/controlling the roof face from vertexes and/or having an option to control both angles/slopes.

I understand this is not such a common issue, nevertheless it would be nice to have higher flexibility on the roof face tool and/or the possibility to generate a roof via “direct” modeling rather than inserting geometric data. I’ll try to submit it as a request, with a wider overview on the tool.

Edited by STR

We have done a lot of roofs like this, and it is just a matter of working out the roof plane direction and pitch. You can create a 3D object of the roof plane first to work out both of those.

Diego, a Roof has to be a planar surface.

When I plot what you have drawn with those dimensions with 3D loci and then draw a nurbs surface using those points I don't come up with a planar surface.

Thank you all for your kind suggestions: attached the issue solved with the workaround suggested by Taproot & BG (no trigonometry, geometry only).

Still think that a "how-to-model" approach on the software side, rather than a "data-input" approach, could make the roof face tool as easy to use as some other VW 3d tools.

Edited by STR

Well done!  I'm glad you were able to persevere to a solution.

Great solution!
Congrats!

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