Inheritance without module pattern and no use of __proto__

gistfile1.js

// define a new type SkinnedMesh and a constructor for it
function SkinnedMesh(geometry, materials) {
  // call the superclass constructor
  THREE.Mesh.call(this, geometry, materials);
 
  // initialize instance properties
  this.identityMatrix = new THREE.Matrix4();
  this.bones = [];
  this.boneMatrices = [];
  ...
};
 
// inherit behavior from Mesh
SkinnedMesh.prototype = Object.create(THREE.Mesh.prototype);
SkinnedMesh.prototype.constructor = SkinnedMesh;
 
// define an overridden update() method
SkinnedMesh.prototype.update = function(camera) {
  ...
  // call base version of same method
  THREE.Mesh.prototype.update.call(this);
};