topic Re: Non-horisontal roof ridge in Modeling

Non-horisontal roof ridge

Anonymous — Tue, 23 May 2023 12:15:42 GMT

Hi.

I'm struggling with how to make a roof ridge that is not horizontal. I'm just beginning this BIM model and will naturally be working on it for the next 2-3 years so the solution has to be practical in terms of future skylight, sections...

What is the best way to approach this?

Re: Non-horisontal roof ridge

Erwin Edel — Mon, 16 Oct 2017 13:09:31 GMT

Unless the gutter is sloped as well or your building footprint is not a rectangle, you will have to bend or curve the roof planes to do that.

If you do want a sloped gutter or a trapezium footprint, the ridge will be sloped.

Build your model with cardboard and you will see how the roof planes work.

Re: Non-horisontal roof ridge

Anonymous — Mon, 16 Oct 2017 13:18:34 GMT

There should be no need to curve that roof...

Re: Non-horisontal roof ridge

Erwin Edel — Mon, 16 Oct 2017 13:28:23 GMT

If you want to re-invent the rules of geometry, I'm not stopping you

Re: Non-horisontal roof ridge

Anonymous — Mon, 16 Oct 2017 13:32:00 GMT

But I'm not inventing anything... The roof is flat.

Re: Non-horisontal roof ridge

Erwin Edel — Mon, 16 Oct 2017 13:48:23 GMT

Your roof pivot lines need to form a trapezium shape, that is the only way you will make that shape, without splitting that triangle in to two triangles or twisting the roof in to a curved shape.

Re: Non-horisontal roof ridge

runxel — Mon, 16 Oct 2017 15:58:16 GMT

I'd just like to drop the Mesh to Roof command.
Might be helpful here.

Re: Non-horisontal roof ridge

Anonymous — Mon, 16 Oct 2017 16:54:35 GMT

Thank you, both of you.

I was hoping there would be a solution where I could use the multi-plane roof, and easily adjust the angles as the project develop. It seems I have to use single-plane roofs, which is OK, but a bit more work...

Re: Non-horisontal roof ridge

Stephen Dolbee — Mon, 16 Oct 2017 16:56:55 GMT

If your roof planes are not parallel with each other, your ridge will not be horizontal. It will slope up or down.

Re: Non-horisontal roof ridge

Anonymous — Mon, 16 Oct 2017 17:09:57 GMT

Yes, the multi-plane does that...

Unfortunately the moment the footprint becomes something else than a rectangle the top ridge point is un-movable? That is very inconveniant at such an early stage...but probably because of geometry constraints.

Re: Non-horisontal roof ridge

Aaron Bourgoin — Mon, 16 Oct 2017 17:19:10 GMT

I would suggest you look at using a combination of a mesh to establish and anchor key points of your roof and the "Mesh-to-Roof" add-on from the Goodies.

Tool info here: https://helpcenter.graphisoft.com/tips/archicad/goodies/mesh-to-roof-add-on/

Download Page here: http://www.graphisoft.com/downloads/goodies/index.html

Re: Non-horisontal roof ridge

Anonymous — Mon, 16 Oct 2017 18:03:07 GMT

Thanks.

Yes, I will have a look at the add-ons.

Re: Non-horisontal roof ridge

Barry Kelly — Tue, 17 Oct 2017 00:50:30 GMT

Einar wrote:
Yes, the multi-plane does that...

Unfortunately the moment the footprint becomes something else than a rectangle the top ridge point is un-movable? That is very inconveniant at such an early stage...but probably because of geometry constraints.

That is because it is really no longer a ridge.
It is a hip - bisecting the angle of the gutter (eave) lines of the adjoining roof planes.

I find using single roof planes can often be easier than using the multi-plane roof when odd shapes are involved.
Place the single plane pivot line and define the slope.
If you know the shape of the roof plane you can then model that - otherwise approximate it and use the roof edge adjust command to determine the hips and ridges.
i.e. with roof tool active, select one roof then CTRL click the edge on any other roof plane that you want to join to the selected roof.
Then select the other roof and CTRL click the adjoining edge on the first roof.

You can even place single roof planes in 3D if all you know is 3 height points for that roof plane.
It will create the pivot line at the correct position perpendicular to the roof pitch.

Barry.

Re: Non-horisontal roof ridge

Anonymous — Tue, 17 Oct 2017 17:07:42 GMT

Super tip! Thanks.