External render

Hi,

How can I access the blender’s frame / rendering buffers using an external rendering engine.

I am trying to create a rendering engine that reads the internal’s 3D blender model and shows the result on blender.

I follow the link http://www.blender.org/documentation/blender_python_api_2_57_release/bpy.types.RenderEngine.html#bpy.types.RenderEngine.begin_result, but the problem is that I don’t known how to fulfill the ‘layer.rect’ with the output of my render engine. Making it impossible for me to show the results.

best regards,
Sérgio Carvalho