Creating Blue Mars .cgf (geometry) files
From Blue Mars Developer Guidebook
Contents |
Exporting from Maya
Before exporting, transformations should be collapsed using Modify -> Freeze Transformations.
To export all geometry, select File -> Export All....
To export only specific geometry, highlight the desired geometry and select File -> Export Selection....
Click on Options... to open the Export Options window and set the various options as shown below:
Click on Export All (or Export Selection) or Apply.
Set Files of type to "COLLADA exporter (*.dae,*.xml)". When typing in the filename, do not forget to include the .dae extension.
Exporting from 3ds Max
To export all geometry, select File -> Export....
To export only specific geometry, highlight the desired geometry and select File -> Export Selected....
Set Save as type to "COLLADA (*.DAE)". When typing in the filename, do not forget to include the .dae extension.
After you click Save, the Export Options window will open. Set the options as shown below:
Physics Proxies
The CryEngine2 Exporter plug-in for 3ds Max uses a special Crytek Shader material to specify which objects are to be used as physics proxies. Unfortunately, when using the ColladaMaya and the ColladaMax plug-ins, the physics proxy material parameters are not supported and are not exported into the COLLADA .dae file.
bmImport and bmImportCmd replace the original CryEngine2 Exporter mechanism by applying Proxy materials, to identify which objects are to be used as physics proxies. A Proxy material must have a name postfixed with the string proxy. Examples of valid Proxy material names include "woodProxy", "bluePROXY", and "red_color_proxy". The actual material settings of a Proxy material are unimportant. A Proxy material should be applied to each physics proxy object. The proxy object must be linked, as a child, to the rendered object.
Occlusion Objects
This mechanism remains essentially unchanged from the CryEngine2 Exporter plug-in for 3ds Max. The occluder object must be linked, as a child, to the rendered object. The occluder object must be named $occlusion, or _occlusion. The latter naming convention was added to address naming issues in Maya.
Level-of-Detail (LOD) Objects
This mechanism also remains essentially unchanged from the CryEngine2 Exporter plug-in. The LOD objects must be linked, as children, to the original (LOD0) high-resolution object. The LOD objects must have the name $lod1, $lod2, et cetera. As with occlusion objects, LOD objects may alternatively be named _lod1, _lod2, et cetera, to address the naming issues in Maya.
A maximum of six (6) LODs are supported per object.
Pickable Objects
The CryEngine2 Exporter plug-in for 3ds Max uses dummy helpers to identify a "grab-helper" which turns an object into a pickable object in the Sandbox2 editor. Unfortunately, when using Maya, these dummy helpers are not supported and cannot be exported by the ColladaMaya plug-in into the COLLADA .dae file.
bmImport and bmImportCmd support the original CryEngine2 Exporter mechanism of using dummy helpers in 3ds Max. In addition, bmImport and bmImportCmd have been augmented to allow the creation of Helper objects in Maya. A Helper object must have a name postfixed with the string Helper. Examples of valid Helper object names include "grab_onehanded_01Helper" and "grab_twohanded_01Helper". The Helper object must be linked, as a child, to the rendered object.
Material File (.mtl) Generation
bmImport and bmImportCmd can create a basic Blue Mars .mtl (material) file for the converted geometry, which can be edited directly by the user in any text editor, or via the Sandbox2 editor. The material file will have the same filename prefix as the .cgf file.
Currently, the maximum number of materials, incl. all submaterials, is limited to 31.
Only basic 2D texture maps and lighting parameters are generated by bmImport and bmImportCmd. Material parameters are expected to be edited in the Sandbox2 editor.
Mental Ray shaders do not export correctly and should not be used as materials.
Limitations and Known Bugs
- Only polygonal geometry is supported. NURBS surfaces are not supported.
- bmImport and bmImportCmd will automatically triangulate polygonal geometry; however, the built-in triangularization, while computationally accurate, may introduce undesirable changes in the appearance of the model. In addition, the built-in triangularization may generate additional triangles and exceed the polygon count limit of the Resource Compiler (see below). Thus, it is strongly recommended that the 3D artist perform the triangularization in Maya or 3DS Max, and evaluate the results on the model prior to export.
- A single object cannot have more than 65,535 vertices, normals, faces, polygons, et cetera. bmImport and bmImportCmd can process the object, but the resulting file may not be compatible with the Resource Compiler or the Sandbox2 editor.
Copyright © 2008-2009 Avatar Reality, Inc.
Return to Using the Blue Mars COLLADA asset importer
Blue Mars Guidebook Privacy Policy
Blue Mars Guidebook Community Guidelines
