Reading and rendering a digital elevation model (DEM) in VTK

I have a few questions regarding how to best generate a 3D rendering of digital elevation model (DEM).

  1. Is there a way to access via python bindings the GDALRasterReader() function? This functionality appears in VTK but I cannot get access to it. My DEM is a geotiff and it would be ideal to use it. If this is not possible, how would I read information contained in this image (elevation information at regular intervals)?
  2. What is the best way to generate a 3D model once geotiff information has been read? How can I do a Delaunay triangulation so that I get a surface oriented correctly (with y being the elevation)?