Render Layers Maya

We have been learning how to create layers in Maya for certain things such as shadows etc. There was a file that we were to download with the correct needs for creating the layers. The tutorial guide we was given simply goes like this;

ColourPass

1. Select from the outliner window Alpha block, Lamp light and Room light.
2. Go to render in the Channel box/layer editor.
3. Click create new layer and assign selected objects.
4. Rename the layer ColourPass.
5. Click render settings on the ColourPass layer.
6. Right click the file name prefix.
7. Go to remove layer override.
8. Change the name in the render settings to ColourPass.
9. Make it a TIFF file format.

ShadowPass

1. Select from the outliner window Alpha block, Table top, Placemat, Lamp light and Room light.
2. Go to render in the Channel box/layer editor.
3. Click create new a layer and assign selected objects.
4. Rename the new layer ShadowPass.
5. For the light object, click attribute editor.
6. Right click use ray trace shadows.
7. Create layer override.
8. Click to enable shadows.
9. For the amounts, they are to be set as; Light Radious-3, Shadow Rays-12, Ray depth limit-3.
10. Select Placemat, go to attribute editor.
11. Click render stats.
12. Turn off cast shadows.
13. Right click ShadowPass layer.
14. Go to attributes.
15. Click presets, then click shadow.
16. Click render settings in the ShadowPass layer.
17. Right click file name prefix.
18. Go to remove layer override.
19. Rename in the render setting ShadowPass.
20. Make it a TIFF file format.

ReflectionPass

1. Select from the outliner window Alpha block and Placemat.
2. Go to render in the Channel box/layer editor.
3. Click create new layer and assign selected objects.
4. Rename the new layer ReflectionPass.
5. Select the Alpha block.
6. Assign existing material by right clicking the Alpha block.
7. Assign the mirror shader.
8. Add both light components to the ReflectionPass layer. 
9. Go to Alpha block attributes.
10. Turn off primary visibility.
11. Click Render settings of the ReflectionPass layer.
12. Right click file name prefix.
13. Remove layer override.
14. Rename ReflectionPass.
15. Make it a TIFF file format.

OcclusionPass

1. Select from the outliner window Table top, Placemat and Alpha block.
2. Go to Render in the Channel box/layer editor.
3. Create new layer and assign selected objects.
4. Rename OcclusionPass.
5. Right click OcclusionPass layer.
6. Go to attributes.
7. Go to presets, click occlusion.
8. Go to the OcclusionPass layer.
9. Click render settings.
10. Right click file name prefix.
11. Remove layer override.
12. Rename OcclusionPass.
13. Right click image format.
14. Remove layer override on the image format.
15. Make it a JPEG file format.
16. Change the settings to override the Alpha channels. 

Rendering

1. Space bar on hold in the perspective mode.
2. Click render.
3. Click batch render. 
4. Make sure the settings are correctly suited.