title: WebGL 3d usage for depth sorting 2d objects
body: <p>This question has a strong relation with my other question:
  <a href="https://stackoverflow.com/questions/40575771/isometric-rendering-without-tiles-is-that-goal-reachable">Isometric rendering without tiles, is that goal reachable?</a></p>
  
  <p>I want to depth sort objects in an isometric world (html5 canvas).
  The world is not tiled, so every item in the world can be placed on each x, y, z coordinate. Since it's not a tiled world, depth sorting is hard to do.
  I even want that if items intersect, that the visible parts are drawn as if it were intersecting parts in a fully 3d world.
  As people answered in my other question, this can be done by representing each 2d image as a 3d model.
  I want to go on with the solution given in the following comment on that question:</p>
  
  <blockquote>
    <p>You don't have to work in 3D when you use webGL. WebGL draws polygons and is very quick at drawing 2D images as 4 verts making a small fan of triangles. You can still use the zbuffer and set corners (verts) to the z distance. Most of the 2D game libraries use webGL to render 2D and fallback to canvas if webGL is not there. There is also a webGL implementation of the canvas API on github that you could modify to meet your needs. 
    (<a href="https://stackoverflow.com/questions/40575771/isometric-rendering-without-tiles-is-that-goal-reachable#comment68512177_40575771">comment link</a>)</p>
  </blockquote>
  
  <p>So, you could see the 'logic' as 3d models. The z-buffer of webGL provides correct rendering. The rendering pixels itself are pixels of the 2d images. But I don't know how to do this. Could someone further explain how to get this done? I read a lot of information, but that's all about real 3d.</p>