Build phenomena

 
 
 

The Phenomenizer is a mental ray for Maya extension that allows you to turn any shading graph consisting of mental ray nodes into a mental ray Phenomenon. This Phenomenon encapsulates the shading graph into a new single shading node with custom input and output parameters, and hides the internal details from the user. Phenomena are stored in regular .mi files, and can be loaded into Maya as regular shader nodes using the mental rayShader Manager. See the mental ray reference guide for more details on Phenomena.

Creating Phenomena

The basis for building and attaching Maya shading graphs is the Maya utility node Mentalray Phenomenon, also referred to as Phenomenizer node (Maya node type: mentalrayPhenomenon). It allows you to attach Maya shading graphs easily, and automatically generates the required input attributes on the Phenomenon node. It also provides access to all the advanced mental ray Phenomenon options. The full phenomenon description can be exported to a .mi file for later use.

Phenomenon Options

All Phenomenon options are available in the Attribute Editor of the node grouped under the Options tab. These include version number, apply flags, and requirements. For more information, see Phenomenon in the mental ray reference guide.

Workflow in Maya

To build your phenomenon in Maya

  1. Build the initial Phenomenon as follows:
    • Create a Phenomenizer node (In the Hypershade, select Create > mental ray Miscellaneous).
    • Create a mental ray render node intended as the Phenomenonroot. The output of this node determines the output attributes of the whole Phenomenon.
    • Shift-drag the node onto the Phenomenizer node. The Connection Editor opens with the two nodes selected.
    • Connect the message attribute of the node to the Phenomenizerroot attribute. You may need to select Left/Right Display > Show Hidden to see the message attribute.
      Note

      Upon connecting the root node of the Phenomenizer, all additional output (read-only) attributes of that node are also dynamically added to the Phenomenizer node as output. They are considered fields of the final output parameter struct of the Phenomenon.

  2. Build the shading graph content
    • Create and connect new nodes to the root node as driving nodes.
    • Set input attributes of those nodes to the desired constant values if they are not going to be exposed as interface parameters.
  3. Build the Phenomenon interface

    Create input parameters for the Phenomenon from input attributes of any content node by drag-dropping the Phenomenizer onto the desired node, and then connecting an interface array element to the desired attribute.

    Note
    • Upon connecting an interface element, the attribute behind that plug is dynamically copied to the Phenomenizer, and can be connected to other nodes. Unlike the root attribute (there can only be one root), more than one connection may originate from a single interface element. The Phenomenizer checks if new connections are compatible with the existing dynamic attribute. If not, the connection is refused and an error message is reported.
    • When disconnecting interface elements or the root attribute, the corresponding dynamic attributes are also deleted.

To export the phenomenon to a .mi file

  1. Select the Phenomenon node in Maya.
  2. Select File > Export Selection >
    • Set File type to mentalRay
    • Turn on Export selected items only
    • Select the filters Factory shaders, and Phenomenizers.
  3. Click the Export Selection button.

General Rules

Limitation