Render passes

After adding fur to the rest of the model render times jumped to almost 20 minutes a frame, an unacceptably expensive render. To reduce it I decided to render the fur separately without raytrace shadows I did this and it reduced the render time to twelve minutes, the problem was the reflection pass was empty for the glass cases. I created a new simple scene and practised with some different materials and discovered the mistake was an oversight on my part I was using the mia_material_x and to enable render passes it needed to be a mia_material_x_passes. Duh! a bit obvious now. Heres some pics of my 'practice'.

Diffuse no shadows

Shadows (in maya they render inverted.)

Ambient Occlusion

Z-depth (for post production depth of field in AE)

Reflection pass, the left column was also reflective but is missing because it was a mia_material_x not the mia_material_x_passes material.

All layers composited (I went back and rendered the column correctly.)

There are plenty of tutorials out there. Quite a clear one can be found here: Maya Render Pass Tutorial  http://www.pixelcg.com/blog/?p=924