Houdini 16.5 Nodes Render nodes

Tractor render node

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

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Tractor 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 Tractor script and start the Tractor program on the script file. Tractor 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, Tractor 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

Submit Job

Submits the job to the Tractor based farm.

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 behavior 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 Current 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.

For example, if the parameters are set to: table>>

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: table>>

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.

Generate disk file only

Instead of invoking Tractor 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 Tractor from generating all IFD’s simultaneously. See the Tractor documentation for more information.

Job: At Least/Most Hosts

A Job is a task list which has a hierarchy of dependent tasks. See the Tractor 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.

Locals

N

The current frame of the range specified. This always starts at 1.

NRENDER

Total number of frames being rendered.

Render nodes

  • Agent

    This output operator is used to write agent definition files.

  • Alembic

  • Archive Generator

    Generates disk-based archives which can be used by either mantra or RIB renderers.

  • Bake Animation

    Bakes animation from object transforms and CHOP overrides.

  • Bake Texture

    Generates a texture map from one or more objects' rendered appearance.

  • Batch

    Renders the input ROP in a single batch job.

  • Brick Map Generator

    Allows you to convert Houdini volume primitives into Pixar brickmap files.

  • Channel

    The Channel output operator generates clip files from a particular CHOP.

  • Composite

    The Composite output operator renders the image(s) produced in the Compositing Editor.

  • DSM Merge

    Merges two or more deep shadow/camera map files.

  • Dynamics

    Saves the state of a DOP network simulation into files.

  • Fetch

    Makes a dependency link to a ROP in a different network.

  • Filmbox FBX

    Exports entire scenes to FBX files.

  • Frame Container

    Prevents frame dependency changes in the contained nodes from affecting its inputs.

  • Frame Depedency

    Allows an output frame to depend on one or more input frames.

  • Geometry

    Generates geometry files from a SOP or DOP network.

  • HQueue Render

    HQueue, or Houdini Queue, is a distributed job scheduling system.

  • HQueue Simulation

    HQueue, or Houdini Queue, is a distributed job scheduling system.

  • MDD Point Cache

    This output operator is used to write an MDD animation file.

  • Mantra

    Renders the scene using Houdini’s standard mantra renderer and generates IFD files.

  • Mantra Archive

    Generates disk-based archives which can be used by mantra.

  • Merge

    Merges several render dependencies into one.

  • Net Barrier

    Blocks the ROP network until synchronization occurs.

  • Null

    Does nothing.

  • OpenGL

    Render an image using the hardware-accelerated 3D viewport renderer.

  • Pre Post

    Renders ROPs before and after a main job.

  • RenderMan

    Renders the scene using Pixar’s RenderMan renderer.

  • RenderMan

    Renders the scene using Pixar’s RenderMan RIS renderer.

  • RenderMan Archive

    Generates disk-based archives which can be used by RenderMan .

  • Shell

    Runs an external command.

  • Subnetwork

    The SubNetwork output operator provides an easy way to manage large number of output operators.

  • Switch

    Renders one of several inputs.

  • Tractor

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

  • Wedge

    Re-renders the same ROP multiple times with different settings

  • Wren

    This output operator is used to drive the Wren rendering program.