Wedge render node

Re-renders the same ROP multiple times with different settings

The Wedge ROP will render the specified ROP multiple times. Each time it will vary some parameters in the .hip file. This is useful for exploring how changing parameters will change the look for expensive functions.

The WEDGE variable will be set to a string that describes the current set of parameters. Using this in filenames output can ensure each wedge doesn’t conflict with the other wedges. Alternatively, if one is wedging to mplay, the individual wedges will render together. The output file could be set to filename_$WEDGE_$F.pic to ensure each wedge gets its own image sequence.

If wedging images, you can also use the hwatermark program to stamp the images with the wedge name. Setting the Post Frame Script to 

unix hwatermark -x 4 10 -m "$WEDGE" `chs("vm_picture")` `chs("vm_picture")` $HFS/houdini/fonts_texture/Fixed-Bold.24

The WEDGENUM variable will be set to the currently processed wedge number. This ranges from 0 to one less than the number of wedges. If you render a specific wedge with the Wedge Range, WEDGENUM will be set to that wedge number.

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.

Render with Take

Uses the settings in a particular take while rendering. Choose “Current” to use the current take when rendering.

Prefix

This prefix is added at the front of the WEDGE variable. This can be used to separate different sets of wedges.

Wedge Range

All Wedges will cause every computed wedge to be rendered at once. Alternatively, one specific wedge can be rendered. The latter is useful if manually splitting up the wedges across machines, which may be necessary for simulations.

Output Driver

Which ROP will be run for each wedge. The ROP should have a parameter called “take” for take based wedging to work. If it outputs to a file, the filename should have $WEDGE in it to avoid writing the same file twice.

Wait for Render to Complete

Sets the Block Until Render Completes temporarily on the Output Driver. This avoids all the wedges being started simultaneously, which can inconvenience a single-user machine. However, by not blocking, you can return control to Houdini quickly while waiting for the renders to run in background.

Wedge Method

Controls how the scene is varied.

By Channels

Each of the Wedge Parameters is varied according to its number of steps and range and applied to its specified channel. All combinations of the parameters are then wedged. The total number of wedges is the product of all of the step values.

By Take

One wedge is performed for each immediate child of the given parent take. The output driver’s take parameter is set to each child take’s value.

Parent Take

In By Take wedging, this is the name of the parent take. Only immediate children of this take are used for wedges.

Random Samples

Instead of uniformally sampling each range, a random value will be picked inside the range for each sample.

Number of Samples

Determines how many wedges will be run when in random sampling mode.

Random Seed

The seed used for generating the random samples. Changing this will create a different set of random samples.

Wedge Parameters

The number of parameters to use in By Channel wedging. Each paramater is a single float value which is divided uniformally across a given interval.

Name

The english name of the channel. This is added to the WEDGE variable. If blank, the channel name is used.

Channel

The channel path to vary. This is a full channel path, a path to a node followed by the name of a channel. Note that it is not a parameter path: /obj/geo1/tx is legal but /obj/geo1/t is not.

Range

The minimum and maximum values that the channel will vary over.

Steps

The number of steps that the range will be broken into. Ignored if random sampling is performed.

Usages in other examples

Example name Example for