Update README.md

README.md

@@ -49,6 +49,8 @@ function renderLoop() {
 
 ## TilesRenderer
 
+_extends [TilesRendererBase](https://github.com/NASA-AMMOS/3DTilesRendererJS/blob/master/src/base/TilesRendererBase.js), which can be used to implement a 3d tiles renderer in other engines_
+
 ### .errorTarget
 
 ```js
@@ -171,6 +173,12 @@ setResolution( camera : Camera, x : number, y : number ) : boolean
 setResolutionFromRenderer( camera : Camera, renderer : WebGLRenderer ) : boolean
 ```
 
+## PriorityQueue
+
+TODO
+
+## LRUCache
+
 # LICENSE
 
 The software is available under the [Apache V2.0 license](../LICENSE.txt).