Overview
3Delight For Maya gives you The MEL Scripts group of attributes provides the ability to execute MEL scripts at certain locations stages during the rendering process. This opens up the possibility of doing whatever tweaks required before each renderingat these stages. Since 3delight 3Delight comes with a set of MEL bindings for the RenderMan standard, it also becomes possible to insert RenderMan commands anywhere during rendering (see MEL RenderMan Binding). This is the equivalent of “RIB Boxes” in other packages softwares but with the added flexibility of a scripting language. In addition to the MEL scripts insert points listed here, there are others available in geometry attribute nodes Geometry Attribute Nodes (see Geometry MEL Scripts) and in the light attribute nodes Light Attribute Nodes (see Light MEL Scripts).
The following variable 'string $render_pass' is automatically defined in the context of these scripts execution:
string $render_passThis variable is and is assigned the current render pass Render Pass node name.
The MEL Scripts group
Pre Render MEL
Post Render MEL
Specify scripts to run before the rendering starts and after the rendering is finished, respectively. Those scripts are guaranteed to run first and last. They are also executed outside of any RiBegin/RiEnd block, so these scripts are not appropriate for invoking RenderMan commands.
Pre Frame MEL
Post Frame MEL
Specify scripts to run before and after each frame, respectively. These two scripts are the very first and last things executed for each frame; they are called even before and after the RiBegin/RiEnd block, so these scripts are not appropriate for invoking RenderMan commands.
Post Option MEL
Specifies a script to execute after all RenderMan options have been issued, but before the camera transforms. This can be used to override any optionoptions.
Pre World MEL
Specifies a script to execute just before RiWorldBegin which is also right after where the camera transforms are issued.
Post World MEL
Specifies a script to execute right after RiWorldEnd (but before RiFrameEnd).