topic Re: City Engine to Arcpro -Export Parcel to GIS in ArcGIS CityEngine Questions

City Engine to Arcpro -Export Parcel to GIS

Tiwene_Roberts — Mon, 20 Oct 2025 09:50:46 GMT

Im learning by doing with limited knowledge and experience. The code snippet below I've used to use and offset distance from the boundary to create an inner parcel.

What I'm having trouble with is being able to export the resulting face (boundary) geomentry of the inner lot to gis as a layer.

Any suggestions? Thanks in advance

// inner_parcel_export.cga

// ------------------------------------------------------

// Purpose: Create an inner parcel offset inward from all boundaries by 1 m

// and mark it for export to GIS (e.g., as shapefile or GDB).

// ------------------------------------------------------

// -----------------

// Attributes

// -----------------

attr offsetDist = 1.0 // inward offset distance in meters

attr subparcel = 0 // attribute flag: 1 = inner parcel

attr parcelType = "outer" // attribute tag: outer/inner

// -----------------

// Start Rule

// -----------------

@StartRule

Lot -->

// Assign attributes to the outer parcel

set(subparcel, 0)

set(parcelType, "outer")

// Offset inward by offsetDist to create a new shape

offset(-offsetDist) InnerBoundary

// -----------------

// Inner boundary component handling

// -----------------

InnerBoundary -->

// Split geometry into inside and border parts

comp(f) {

inside : InnerParcel

| border : OuterParcel

}

// -----------------

// Inner parcel definition

// -----------------

InnerParcel -->

set(subparcel, 1)

set(parcelType, "inner")

color("#ffcc99")

// Keep as polygon shape for GIS export (no extrusion)

// -----------------

// Outer parcel definition (optional visualization only)

// -----------------

OuterParcel -->

set(parcelType, "outer")

color("#99ccff")

Re: City Engine to Arcpro -Export Parcel to GIS

ThomasFuchs — Tue, 21 Oct 2025 08:26:59 GMT

Hello @Tiwene_Roberts

Thanks for sharing your code snippet—it's awesome that you're diving in and learning by doing with CityEngine. I understand the challenge of exporting that inner parcel boundary as a GIS layer. I'll walk you through a straightforward solution below.

When exporting a Model to FileGDB, it is not possible to only select certain faces of a Model. Therefore, all face geometries in the CGA code, that you do not want to export, have to be NILed.
NIL operation—ArcGIS CityEngine Resources | Documentation

// ----------------- // Outer parcel definition (optional visualization only) // ----------------- OuterParcel --> NIL // set(parcelType, "outer") // color("#99ccff")

Then Export to the model to FileGDB and make sure to only export Models:
Export FileGDB (Esri File Geodatabase)—ArcGIS CityEngine Resources | Documentation

Re: City Engine to Arcpro -Export Parcel to GIS

Tiwene_Roberts — Thu, 23 Oct 2025 02:02:23 GMT

Hello Thomas,

Thank you kindly for your solution it worked perfectly not to mention a better understanding of the application. ✌