RIB ContainerBasic Tag
The RIB Container tag is a simple mechanism with which arbitrary RenderMan® renderer statements can be added to the RIB Stream. This adds a lot of flexibility but be careful - you should know exactly what you are doing because you can easily mess up a rendering. You should refer to the books mentioned in "Understanding RenderMan" so you know how to work with this tag
A RIB Container can be attached to every object in the scene and the RIB code you specify is written to file when a particular object is written. The type of object you apply the RIB Container tag to can have great influence on where in the RIB stream your data gets written.
For normal objects this is a straightforward process, as the scene hierarchy will be replicated in the RIB file. However, certain special objects will be written to different locations within the file. Light Sources will always be defined at the beginning of the scene description, so applying a RIB Container tag to a light source will also assure your custom RIB will be written to the beginning of the scene description.
Applying the RIB Container tag to an Environment Object will ensure the tag is written immediately following the light sources, but prior to all other objects. Applying it to the camera will write the custom RIB before WorldBegin (see "Understanding RenderMan”), which is important because only there you can set RIB options or even replace the camera.