Renders For The Finished Film...

I am not overall happy with the resulting renders for my film. I should of got some nice shadows on the curtains and elsewhere on the set, but for some reason, the shadows disappeared on the final batch render. I know they were there before hand, as I took the first render below,

The two next images are of the final renders, we can see that there is no shadow on the curtain and there is a strange shadow appearing on the far wall. I'm not sure if this is as a result of the file not rendering the week before, and possibly still having problems with Mental Ray as a result.

I had hoped to fix the shadow problem by adding a shadow pass, and as I have never done one before, I had to learn how very quickly. It was very simple to do, once I knew how, but for some reason all that was rendering out was a black picture. So I asked Matt to take a look to see if knew why. He managed to fix it by pressing a button which I had missed out. The image below is the result:

Below is the result of multiplying the shadow pass over the colour pass, I think it works well as a test, and I was planning on doing a shadow pass for my last scene, but when I started the batch render, the shadow pass stopped working again, the reason why, I am not sure. Though, for my future re-render of some of my scenes, I will try to use a shadow pass, as I am more likely to get the shadows I want, and that work with the set using Depth Map Shadows.