topic Re: Weird roofGable behavior on square shapes in ArcGIS CityEngine Questions

Weird roofGable behavior on square shapes

LR — Tue, 12 Jul 2016 13:35:16 GMT

I'm having trouble getting gable roofs to work on square shapes. See attached images. In CE 2015.2, when you rotate the scope by 90°, the roof turns flat. If you rotate it by 270°, it turns into a pyramid! In CE 2016.0, the roof is messed up no matter what. This can be "fixed" by making the shape slightly irregular, but is that expected behavior? Seems rather strange.

Re: Weird roofGable behavior on square shapes

CherylLau — Tue, 12 Jul 2016 14:47:11 GMT

This is a known bug that we are currently working on, but we didn't know about the rotation details, so thanks for pointing this out.

Re: Weird roofGable behavior on square shapes

LR — Wed, 13 Jul 2016 10:30:05 GMT

Ah, I see. Good luck fixing it.

Do you maintain a public bug list? I couldn't find anything, or looked in the wrong places.

Re: Weird roofGable behavior on square shapes

ThomasFuchs — Thu, 28 Jul 2016 14:33:01 GMT

Hello L R,

there is no public known issues list for CityEngine.
However this forum can be used to report issues, share workarounds and updates for bug fixes.

It is regularly synced with the development backlog of the software.

Re: Weird roofGable behavior on square shapes

LR — Fri, 29 Jul 2016 12:22:44 GMT

Is this another bug? When I change the index on a shape with many faces, the roofShed operation doesn't produce the expected results either.

Re: Weird roofGable behavior on square shapes

CherylLau — Fri, 29 Jul 2016 15:28:15 GMT

Could you explain further why you think it doesn't produce the expected results? Could you describe your expected result please?

Re: Weird roofGable behavior on square shapes

LR — Fri, 29 Jul 2016 18:34:06 GMT

I'm using byHeight to extrude the roof, so scope.sy should always equal it. As you can see in the console output on the right, when I turn the roof like it's pictured, the model height doesn't match the attribute height - it should meet the purple wedge's top, but it's much lower.

Re: Weird roofGable behavior on square shapes

CherylLau — Tue, 02 Aug 2016 11:27:59 GMT

Would you mind sharing your scene file and rule file so that we could take a closer look at it?

Re: Weird roofGable behavior on square shapes

LR — Fri, 05 Aug 2016 09:59:22 GMT

Here you go. The problem is in new_scene_02.cej. When I was making the scene I ran into another problem I get sometimes: the edges of imported shapes end up jaggy - see new_scene_01.cej.

Re: Weird roofGable behavior on square shapes

CherylLau — Wed, 02 Nov 2016 15:07:45 GMT

Thanks for the files. Now I understand what you mean. Yes, it does seem like there is a bug when putting shed roofs on shapes created by splits. Thanks for helping us find this one.

Re: Weird roofGable behavior on square shapes

ThomasFuchs — Fri, 04 Nov 2016 14:09:20 GMT

Hello L R

Thanks for sending the repro files. I was able to reproduce a case where the import looks the same way. It seems to be an accuracy issue of the generated vertex coordinates. The GDB import should not show such a behavior.

The issue has been reported to the CityEngine development team.