Working with your ColladaLoader from the Cookbook I have found that the method for getting the BoundingSphere does not work right and therefore camera position and displayed bounding sphere are not correct.
I have solved it getting the bounding sphere in sommExtents method with this code:
var bSphere = new THREE.Box3().setFromObject(scene.children[2].children[0]).getBoundingSphere();
which seems to work ok at least with a couple of models from Sketchup.
Working with your ColladaLoader from the Cookbook I have found that the method for getting the BoundingSphere does not work right and therefore camera position and displayed bounding sphere are not correct. I have solved it getting the bounding sphere in sommExtents method with this code: var bSphere = new THREE.Box3().setFromObject(scene.children[2].children[0]).getBoundingSphere(); which seems to work ok at least with a couple of models from Sketchup.
Regards.