Alfred render node

Alfred is a program shipped out with Pixar’s distribution of RenderMan.

All

Parameters

Local variables

Alfred is a program shipped out with Pixar’s distribution of RenderMan. It manages render tasks on a single machine or across a network. This output driver will generate an Alfred script and start the Alfred program on the script file. Alfred must be correctly configured.

When rendering using RenderMan, by default, netrman is used, so the local host must be running the nrmserver software.

When rendering using Mantra, Alfred must be configured to know about Mantra. Please see the read me in $HFS/houdini/scripts/alfred.

Tip

You can add the following selection criteria of mantra:

mantra hserver -h %h -l

which will check to see if there is a running successful hserver on the machine you are going to send a frame to.

Parameters

Render

Begins the render with the last render control settings..

Render Control

Opens the render control dialog to allow adjustments of the render parameters before rendering.

Valid Frame Range

Controls whether this render node outputs the current frame (Render any frame) or the image sequence specified in the Start/End/Inc parameters (Render Frame Range).

Render Frame Range (strict) will render frames START to END when it is rendered, but will not allow frames outside this range to be rendered at all. Render Frame Range will allow outside frames to be rendered. This is used in conjunction with render dependencies. It also affects the behaviour of the 'Override Frame Range' in the Render Control dialog.

Two possible cases where you'd want the strict behavior:

A 60 frame walk cycle written out to a geo, but part of a larger ROP net to render out a larger frame range
A texture loop from 1-20

Otherwise, you will usually set this to non-strict.

Render Any Frame	Renders a single frame, based on the value in the playbar or the frame that is requested by a connected output render node.
Render Frame Range	Renders a sequence of frames. If an output render node is connected, this range is generally ignored in favor of frames requested by the output render node.
Render Frame Range (Strict)	Renders a sequence of frames. If an output render node is connected, this range restricts its requested frames to this frame range.

Start/End/Inc

Specifies the range of frames to render (start frame, end frame, and increment). All values may be floating point values. The range is inclusive.

These parameters determine the values of the local variables for the output driver.

$NRENDER	The number of frames to be rendered by the output driver.
$N	The current frame being rendered (starting at 1 and going to $NRENDER).

For example, if the parameters are set to:

Start	End	Inc
10.5	12	0.5

There will be 4 frames rendered (10.5, 11, 11.5, and 12), so $NRENDER will have a value of 4. $N will have the value:

Frame	10.5	11	11.5	12
$N	1	2	3	4

Render With Take

The output driver will switch to this take before rendering to restore the current take when rendering has been completed.

Control

Output Driver	The output driver used to generate the render files.
Temporary Directory	Location to store temporary files.
Remote Shell	The shell to run on the remote machine. This is only important when using netmantra.
Generate disk file only	Instead of invoking Alfred to run the job immediately, you can create an task list and save it to the disk file.
Disk File	Location where the task list is saved.
Generate Tags	Allows you to choose intensive, hscript, or hrender tags. The default is intensive, which will prevent Alfred from generating all IFD’s simultaneously. See the Alfred documentation for more information.
Job: At Least/Most Hosts	A Job is a task list which has a hierarchy of dependent tasks. See the Alfred documentation for more information.

Scripts

Each script command refers to an hscript command which will be run, regardless of the expression language selected for the parameter. The resulting string will be run as an hscript command.

Note

It is possible to use the python, unix or source hscript commands to perform complex processing.

The commands are always run when rendering occurs. The command checks the parameters of the output driver when it is rendering a range or sending output to a command.

Before the render occurs, Houdini will automatically set the current hscript directory to point to the output driver.

Pre-Render Script	This command is run before any IFDs are generated. It is only run once per render.
Pre-Frame Script	This command is run before each IFD is generated.
Post-Frame Script	This command is run after each IFD is generated. Note Although the IFD may have been generated, this does not necessarily mean that mantra has finished rendering the image when this command is run.
Post-Render Script	This command is run one time, after all IFDs have been generated. Note Although the IFD may have been generated, this does not necessarily mean that mantra has finished rendering the image when this command is run.

Local variables

N	The current frame of the range specified. This always starts at 1.
NRENDER	Total number of frames being rendered.

Usages in other examples

Example name	Example for