Modifying the object added to the scene

add_from_children.js

onModelLoaded: function(collada){
  var object = collada.scene;
  // some stuff here

  var mesh = object.children.filter(function(child){
    return child instanceof THREE.Mesh;
  })[0];

  object.geometry = mesh.geometry;

  scene.add(object);
}

add_generic.js

onModelLoaded: function(collada){
  var object = collada.scene;
  // some stuff here

  var geometries = collada.dae.geometries;
  for(var propName in geometries){
    if(geometries.hasOwnProperty(propName) && geometries[propName].mesh){
      object.geometry = geometries[propName].mesh.geometry3js;
    }
  }

  scene.add(object);
}

adding_specific_property.js

onModelLoaded: function(collada){
  var object = collada.scene;
  // some stuff here

  object.geometry = collada.dae.geometries['space_frig-mesh'].mesh.geometry3js;

  scene.add(object);
}

loading_collada.js

onModelLoaded: function(collada) {
  var object = collada.scene;
  // some stuff here
  scene.add(object);
}