topic Re: Creating Gable Roofs in City Engine 2014.1? in ArcGIS CityEngine Questions

Creating Gable Roofs in City Engine 2014.1?

jeffreymorris1 — Fri, 19 Dec 2014 02:35:57 GMT

How can a create gable roofs in City Engine 2014.1 so that they are created along the Z axis instead of X axis?

Re: Creating Gable Roofs in City Engine 2014.1?

Anonymous User — Sat, 11 Dec 2021 21:43:43 GMT

Gable always follows longest axis, or we would simply use rotateScope(). I tried that first. Here is how I did this (rule is attached):

version "2014.1"

attr switchAxis = true
attr gableAngle = 45

@Hidden
attr originalScopeX = 0
@Hidden
attr originalScopeZ = 0

@StartRule
RoofGableSwitchAxis -->
  # Gable always follows longest axis, or we would simply use rotateScope().
  case switchAxis:
    roofGable(gableAngle)
    set(originalScopeX, scope.sx)
    set(originalScopeZ, scope.sz)
    rotate(rel, scope, 0,90,0)
    s(originalScopeZ,'scope.sx/originalScopeZ,originalScopeX)
    center(xz)
  else:
    roofGable(gableAngle)

Re: Creating Gable Roofs in City Engine 2014.1?

jeffreymorris1 — Sat, 20 Dec 2014 01:50:49 GMT

I tried the rule that you wrote but I got weird roofs. The top of the roof should be even. The shapes came from Open Street Map OSM file.

Re: Creating Gable Roofs in City Engine 2014.1?

BenLeslie1 — Tue, 28 Apr 2015 06:46:03 GMT

You may have unnecessary points in your footprints - simplify them to just 4 vertices and I think you should get better results.

Re: Creating Gable Roofs in City Engine 2014.1?

Anonymous User — Tue, 28 Apr 2015 15:11:16 GMT

You might also try reduceGeometry(edges, 0.1) to reduce the vertex count - the 0.1 part... look in the help manual because I can't remember the exact details of the tolerance parameter.

Re: Creating Gable Roofs in City Engine 2014.1?

jeffreymorris1 — Wed, 29 Apr 2015 01:28:12 GMT

How do I simplify the footprints to just 4 vertices each before extruding them?

Re: Creating Gable Roofs in City Engine 2014.1?

Anonymous User — Wed, 29 Apr 2015 01:33:20 GMT

Try innerRect - you call innerRect inside a mostly square shape, and it gives you exactly 4 vertices.

Also, ignore tip about reduceGeometry(edges, 0.1) I gave up above. I meant cleanupGeometry.

Re: Creating Gable Roofs in City Engine 2014.1?

jeffreymorris1 — Wed, 29 Apr 2015 10:29:16 GMT

How do I combine two or more shapes into one shape?

Re: Creating Gable Roofs in City Engine 2014.1?

Anonymous User — Wed, 29 Apr 2015 23:02:43 GMT

Hold shift while selecting multiple shapes, then look in the Shapes menu for Combine Shapes. You can then apply one rule to the combined shape. This shape combination will not merge coplanar faces or any kind of unioning type stuff.

Re: Creating Gable Roofs in City Engine 2014.1?

jeffreymorris1 — Thu, 30 Apr 2015 00:59:51 GMT

I don't like how InnerRect works. There's Cleanup Shape in the Shapes menu that takes combined shapes and modifies them so that they become one shape. I thought that Combine Shape and Cleanup Shape work but one house still gives me hip roof instead of gable roof on one end. City Engine doesn't let me take a group of shapes like the one above the house with weird roofs and change them into one rectangle.

Re: Creating Gable Roofs in City Engine 2014.1?

Anonymous User — Thu, 30 Apr 2015 01:09:33 GMT

You can force shapes to be rectangular by inserting the built in cube into your scope, and then using either the top or bottom face to replace the starting geometry that you are not getting the right roofs from.

Re: Creating Gable Roofs in City Engine 2014.1?

BenLeslie1 — Thu, 30 Apr 2015 06:42:46 GMT

Indeed, InnerRect is a blunt tool. Threre's a process called CleanupShapes under the Shapes menu - not really familiar with what it does but otherwise I'd look at processing your footprints in ArcMap or some other programme in order to optimise your footprints.

Re: Creating Gable Roofs in City Engine 2014.1?

jeffreymorris1 — Thu, 30 Apr 2015 11:37:10 GMT

How do I import OSM files into ArcMap? How do I install Data Interoperability extension into trial version of ArcMap? The ArcGIS Administrator program said that extension is authorized but not installed. How do I insert the built-in cube into my scope in CityEngine?

Re: Creating Gable Roofs in City Engine 2014.1?

BenLeslie1 — Thu, 30 Apr 2015 12:06:39 GMT

I'd recommend finding an area of GeoNet that is more taylored to these questions - I stick them in 'New to GIS' when I have this type of question.

Completely agree that much of Esri's documentation, error/help messages are seemingly willfully difficult.

Re: Creating Gable Roofs in City Engine 2014.1?

Anonymous User — Fri, 01 May 2015 15:16:56 GMT

hahaha, they might be difficult, but I assure you it is not willfull. The people here are quite nice.