Short description of the COLLADA format
COLLADA is a 3D Asset Exchange Schema owned by the Khronos Group. It defines an XML-based schema to make it easy to transport 3D assets between applications - enabling diverse 3D authoring and content processing tools to be combined into a production pipeline. The intermediate language provides comprehensive encoding of visual scenes including: geometry, shaders and effects, physics, animation, kinematics, and even multiple version representations of the same asset. It is supported by a variety of software systems and libraries and popular in many domains including 3D city models.
The Role of COLLADA in SDDI
Currently, COLLADA files are not being used in the SSD project. However, using 3DCityDB, it is already possible to convert 3D objects such as buildings into COLLADA format for visualization purposes.
Format Specification
Specification documents: https://www.khronos.org/collada/