Draco is a glTF extension for mesh compression along with an open-source library developed by Google to compress and decompress 3D meshes to significantly reduce the size of 3D content. Cesium has been collaborating with Khronos and Google to make Draco a glTF extension, and you can now load Draco compressed models and 3D tilesets in Cesium. Learn more about Draco, how it works and what it has to offer.
The COLLADA to glTF converter online tool allows you to convert your COLLADA models to glTF for use with Cesium. Simply drag-and-drop your COLLADA file (.dae) and any images it references by zipping them together. A self-contained glTF file will be downloaded once the conversion is finished, and a model preview will be shown below.
Cesium has introduced full support for glTF models. A demo with example aircraft, ground vehicle, and character models is available. There is also a tutorial on how to use the Cesium API for glTF, and a tool to convert COLLADA to glTF (based on COLLADA2GLTF).