#CITYENGINE APPLY TEXTURE BUILDINGS HOW TO#

Instead of editing the DEM, this tutorial will show how to create a simple but realistic-looking overpass as a 3D multipatch feature that spans the gap and has a void space underneath. Although this fixes the elevation of the overpass road, it creates an impenetrable wall in the underlying expressway.

#CITYENGINE APPLY TEXTURE BUILDINGS PATCH#

One approach to correcting this situation might be to edit the DEM or add a patch to raise that road and create a flat surface. Lower-resolution DEMs, by comparison, just make features look flat. This type sampling error is commonly seen in high-resolution DEMs in urban environments that show overlapping roadways and structures of different elevations. This exercise starts with an overpass feature that has been poorly captured by the existing 1-meter (m) digital elevation model (DEM) for downtown Philadelphia as shown in Figure 1.

Importing the newly textured overpass back into ArcGlobe.

Applying the extracted imagery to the overpass in SketchUp.

Extracting aerial imagery to use as a surface texture.

Extruding an overpass polygon and exporting it as a 3D multipatch feature from ArcGlobe.

The 16-step workflow is organized into four sections: zip file on ДЇigure 2 (left): Add the polygon feature created in ArcMap to Overpass.3dd.ДЇigure 3 (right): By default, the polygon will drape over the globe surface like a blanket.

Google SketchUp 8 (free version available at /download/).

ArcGIS 10 with the 3D Analyst and Spatial Analyst extensions.

#CITYENGINE APPLY TEXTURE BUILDINGS SOFTWARE#

To complete this exercise, the following software and data are required Some familiarity with Google SketchUp may also be helpful. It's assumed that the reader is familiar with ArcGIS Desktop applications and the ArcGIS 3D Analyst extension, including ArcGlobe. The workflow outlined will familiarize the reader with tools in ArcGIS 10 for importing, exporting, and placing different types of 3D features. It uses a geometrically simple urban feature-a freeway overpass in downtown Philadelphia-and starts with a polygon and some high-resolution aerial imagery. This exercise walks the reader through the process of creating and adding texture to a 3D multipatch feature. ArcGIS 10 introduces a host of new 3D data management and analysis capabilities that enhance 3D analysis. The multipatch, Esri's native 3D feature type, is a key element whether working in ArcGlobe or ArcScene. The 3D virtual city is emerging as an essential GIS tool for visualization and analysis in the urban environment-from placing a proposed building construction in the context of its surroundings to conducting analyses in three dimensions such as line-of-sight or 3D volumetric shadows. Figure 1: This exercise shows how to correct this sampling error, commonly seen in high-resolution DEMs in urban environments.

Cityengine apply texture buildings