.DAE

Introduction

COLLADA (COLLAborative Design Activity) is an XML format for exchanging 3D assets between programs. It was started by Sony Computer Entertainment and is maintained by the Khronos Group. Files use the extension .dae, for digital asset exchange. A file can hold meshes, materials and shaders, cameras, lights, skeletons, skinning, animation and physics.

COLLADA was widely supported through the 2000s and early 2010s. For delivering models to engines and browsers, Khronos now recommends its successor, glTF.

Structure

A DAE file is XML with the root element COLLADA, its schema version and namespace. An asset element gives the units and which axis points up. The content is grouped into libraries: library_geometries, library_materials, library_effects, library_images, library_controllers for skinning, library_animations and library_visual_scenes. The scene element names the visual scene to show. Elements refer to each other by id, written as a URL fragment such as #Cube-mesh.

<COLLADA xmlns="http://www.collada.org/2005/11/COLLADASchema" version="1.4.1">
  <asset><unit meter="1"/><up_axis>Z_UP</up_axis></asset>
  <library_geometries>
    <geometry id="Cube-mesh"><mesh>…</mesh></geometry>
  </library_geometries>
  <library_visual_scenes>
    <visual_scene id="Scene">
      <node id="Cube"><instance_geometry url="#Cube-mesh"/></node>
    </visual_scene>
  </library_visual_scenes>
  <scene><instance_visual_scene url="#Scene"/></scene>
</COLLADA>

Links