Appendix C: Additional mental ray for Maya rendering commands

Custom render region support

The image rectangle of the region render command can be controlled externally. You can do this in one of two ways.

Mayatomr command line option:
```
'-rr/regionRectangle <left,bottom,right,top>' (integer)
```
and mental ray render globals attributes:
- 'regionRectX' (integer)
- 'regionRectY' (integer)
- 'regionRectWidth' (integer)
- 'regionRectHeight' (integer)

The command option takes precedence over the globals attributes.

The attributes have to be created manually on the render globals node (mentalrayGlobals). To render the specified region using the custom attributes, simply issue the 'region render' command. The extra attributes must be deleted from the globals to return to normal behavior.