topic Re: CityEngine - color gradient rule file? in ArcGIS CityEngine Questions

CityEngine - color gradient rule file?

KathrynAngleton — Wed, 21 Mar 2018 19:48:26 GMT

Hi GeoNet community!

By any chance, does anyone know if there's an existing rule file to apply to buildings/shapes to colorize them based off attribute data like you can with color ramps in ArcGIS? I'd like to apply a graduating color scheme to my shapes to emulate a heat map. If no such rule file exists, how would I go about creating one? Would I need to assign RGB/CMYK values to specific data breaks?

Am I better off trying to create a raster of this data and draping it over my extrusions in CityEngine? I'm sure I could do this in ArcScene, but I'm partial to CityEngine's rendering quality.

Thanks!

Re: CityEngine - color gradient rule file?

LR — Sat, 11 Dec 2021 21:31:15 GMT

Write a conditional rule. I usually use Excel for this so I can easily adjust the values.

Example:

case somevalue > 3 && somevalue <= 5: color("#FF0000")
case somevalue > 5 && somevalue <= 10: color("#00FF00")
else: color("FFFFFF")‍‍‍‍‍‍

Re: CityEngine - color gradient rule file?

KathrynAngleton — Thu, 22 Mar 2018 21:40:13 GMT

LR, I found the colorRamp utility function here:

colorRamp function—Esri CityEngine | ArcGIS Desktop

This is what I was looking for, however, my range is very large (min=0, max=39,500) and the default is only 5 breaks. Do you know how to add more breaks? With only 5, every single shape except for one is showing up in the same color.

Re: CityEngine - color gradient rule file?

CherylLau — Fri, 27 Apr 2018 12:56:38 GMT

The colorRamp() functions has access to a list of more than 5 colors. For each color map, there are 36 colors (although I don't guarantee that they look visibly different). Specify the value parameter to be any number in the range [0, 1].