Note #1: Format Recommendations
Format recommendations for various software and functionality are listed in the table below.
Note:
Some of the software and functionality listed require additional plug-ins to load all formats.Software or functionality | Format | Required options |
---|---|---|
ArcGIS Earth | KML | |
Autodesk Max | OBJ, FBX | For obj, enable import of smoothing groups in Max. |
Autodesk Maya | FBX, ABC, OBJ | (ABC materials cannot be imported out of the box in Maya.) |
Autodesk MotionBuilder | OBJ, FBX | |
Blender | OBJ, FBX, ABC | Multitexturing |
Cinema 4D | OBJ, DAE | Multitexturing |
Deep Exploration | OBJ, FBX, DAE | |
SideFX Houdini | ABC, USD | |
Foundry Katana | ABC, USD | |
Lightwave | OBJ | |
Polytrans | OBJ, FBX, DAE | |
e-on VUE | VOB, OBJ |
Note #2: Working with Expensive Assets
If you work with large assets, you can create simplified proxy assets and switch between them with a global level of detail (LOD) attribute. To avoid scattering the LOD attribute over the rules, you can put the conditions into separate asset loader rules, as shown in the following sample code:
attr LOD = 0
...
Shaft -->
s(diameter,’1,diameter) center(xz) color(shaftC) ShaftAsset
ShaftAsset -->
case LOD == 0: primitiveCube()
else: i("path/to/expensive/asset.obj")
...
Note #3: Working with Large Models
To create large models, implement global CGA attributes into the rule sets so you can selectively block the generation of polygon-intensive model features. For example, you can replace high-polygon Greek columns with simple cuboids using an attribute LOD together with a corresponding condition in the CGA rules.
Application example
To render a large scene with Maya or Arnold when you have a CityEngine scene with an LOD switch, export the scene with LOD = 0 to a single .obj file (without textures) and import it. For example, if you import it into Maya, you can quickly set up the lights and camera without using heavy geometry. Once the environment is ready, you can go back to CityEngine and export the scene with LOD = 1 to USD format files and link them to the render setup.
Implementation example
An example of a modified version of the Parthenon temple shape grammar is shown below. The LOD attribute is used.
The temple with LOD = Low, or ~90k polygons
| |
The temple with LOD = High, or ~675k polygons |