Houdini 20.5 Nodes Render nodes

Labs ZibraVDB Compress (Alpha) 0.2 render node

Compresses a VDB sequence and caches it to disk as a single .zibravdb file.

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Since 20.5

As a part of the ZibraVDB for Houdini (Alpha) plugin, this node caches a VDB sequence to disk as a single, highly compressed .zibravdb file. It can compress both animated VDB sequences and static VDB geometries.

The compression often achieves up to 97–99% reduction in VDB file size with minimal quality loss. The compression rate is adjustable for each VDB field, providing independent control over the quality and memory footprint of density, temperature, flame, and other standard or custom fields. Up to 8 float fields can be compressed simultaneously.

Tip

You may also compress SDF VDBs indirectly. Convert SDF VDBs to Fog VDBs before compression and back to SDF VDBs after decompression using the Convert VDB SOP.

Note

Vector VDBs currently cannot be compressed. This feature will be supported in the future. In the meantime, you can split vector VDBs to float VDBs using the VDB Vector Split SOP before compression. After decompression, merge the float VDBs back to vector VDBs using the VDB Vector from Scalar SOP. Please note that compressing vectors is not exactly the same as compressing vector components independently, so this current workaround may yield unexpected results.

Windows

ZibraVDB for Houdini (Alpha) is currently only supported on Windows.

Getting Ready

Acquire License Key

For the plugin to function, Houdini must be able to locate a valid ZibraVDB license on your machine.

  1. Please read the ZibraVDB Terms of Service.

  2. Visit ZibraVDB for Houdini (Alpha) to request a trial license.

  3. After receiving your license key, create a text file in a directory of your choosing and name it zibravdb_license_key.txt. Paste your license key into this text file and save it.

  4. Set up a Houdini environment variable named ZIBRAVDB_LICENSE_KEY and assign it the path to your license key file.

Tip

For example, if you saved the license key file to C:/Users/.../Documents/houdini20.5/zibra/, then you may add the following line to your houdini.env file:

ZIBRAVDB_LICENSE_KEY = C:/Users/.../Documents/houdini20.5/zibra/zibravdb_license_key.txt

You may also use the package mechanism to set environment variables.

Download ZibraVDB Core Library

The plugin also requires the ZibraVDB core library on the back end. (This library and its source code are proprietary to Zibra AI and, therefore, are not included directly in the open-source SideFX Labs package.) The plugin has a built-in method to download this core library, which only needs to be done once (per working environment).

  1. Press the Download Library button on any ZibraVDB node.

  2. In the pop-up window, confirm that you accept the ZibraVDB Terms of Service to proceed.

  3. The download will occur in the background and will typically complete within a few seconds.

  4. A second pop-up window will appear once the download is finished. The core library, ZibraVDBHoudiniBridge.dll, will be saved to $HOUDINI_USER_PREF_DIR/zibra/X_Y/. Alternatively, if the site-specific directory $HSITE is set, it will be saved to $HSITE/zibra/X_Y/.

About ZibraVDB

ZibraVDB is a cutting-edge VDB compression and real-time rendering technology developed by Zibra AI. The compression can currently achieve up to 97–99% reduction in VDB file size with minimal quality loss. The proprietary .zibravdb file format captures an entire VDB sequence in a single file, which can be loaded into applications such as Houdini or Unreal Engine, decompressed on the GPU in real time, and played back in the viewport at speeds significantly faster than native solutions.

For artists, this provides a memory-efficient, high-performance volumetric data pipeline that seamlessly integrates into existing workflows.

It significantly reduces storage costs, improves volumetric data I/O speeds, and ultimately makes it easier and more practical to share working projects and distribute final products containing high-fidelity volumetric effects.

ZibraVDB for Houdini, contributed by Zibra AI, is a SideFX Labs plugin that brings ZibraVDB’s compression, decompression, and accelerated playback capabilities into Houdini’s ecosystem.

Additionally, the compressed .zibravdb files can be used with ZibraVDB for UE. This empowers artists to bring stunning volumetric effects created in Houdini to Unreal Engine and render them efficiently as full 3D ray-marched volumes in real time.

Feedback and Support

If you have any questions, issues, or feedback, please reach out to ZibraVDB Support.

You can also contact SideFX Support and mention that the issue should be directed to the SideFX Labs team.

Parameters

Render to Disk

Compresses the VDB geometry and saves it to disk.

Background Render

In a separate background process, compresses the VDB geometry and saves it to disk. This allows you to continue working in the current Houdini session.

Controls…

Opens a dialog that allows you to launch a one-time render with different frame range and dependency settings.

Valid Frame Range

Specifies whether to compress and render a single frame or a frame sequence of VDB geometry.

Start/End/Inc

The start frame (inclusive), end frame (inclusive) and frame increment, when Valid Frame Range is “Render Frame Range” or “Render Frame Range Only (Strict)”.

Render with Take

Specifies which take to render with.

SOP Path

The path to the SOP node that outputs the VDB geometry to compress and save to disk.

Out File

The file path where the compressed VDB geometry will be saved. The file extension must be .zibravdb. Any missing directories in the path will be automatically created.

Quality

The output quality of the compressed VDB geometry. Higher values result in fewer artifacts but larger file sizes. The file size increases exponentially as this value increases.

Use Per Channel Settings

If on, you can override the output quality of individual channels (i.e. fields), such as density, temperature, flame, etc. Any channel not specified below will still use the value of Quality.

Number of Channels

The number of channels (i.e. fields) to override.

Channel Name

The name of the channel (i.e. field) to override.

Channel Quality

The output quality of the compressed VDB geometry for the specified channel (i.e. field). This overrides the value of Quality for this particular channel.

Pre-Render Script

The script to run before any rendering.

Pre-Frame Script

The script to run before each frame.

Post-Frame Script

The script to run after each frame.

Post-Render Script

The script to run after all rendering.

Download Library

Downloads the core library for all ZibraVDB nodes. You only need to press this once (per working environment).

Examples

Tip

When viewing in Houdini’s Help Browser, please copy the example file’s URL to a regular browser to proceed with the download.

See also

Render nodes

  • Agent

    This output operator is used to write agent definition files.

  • Alembic

    Exports the scene to an Alembic archive. Alembic is a common exchange format for moving geometry and animation between different 3D software packages.

  • 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.

  • Channel

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

  • Composite

    Renders images from a compositing network.

  • DSM Merge

    Merges two or more deep shadow/camera map files.

  • Dem Bones Skinning Converter

    Converts any non-changing topology deforming mesh sequence into a bone-based animation.

  • 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.

  • Filmbox FBX Animation

    Export animation from geometry-based skeleton to an FBX file.

  • Filmbox FBX Character

    Export a skinned character with geometry-based skeleton to an FBX file.

  • Flipbook

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

  • 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.

  • GLTF Character

  • Geometry

    Generates geometry files from a SOP or DOP network.

  • Geometry Raw

    Generates raw binary 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.

  • Hair Card Texture

    Renders hair textures for use on hair cards.

  • Image

    Writes the output of a COP network to disk.

  • Karma

    Renders non-USD scenes using Houdini’s Karma renderer.

  • Labs 3D Facebook Image

    Quickly render a 3D scene to a 2.5D image that can be uploaded to Facebook.

  • Labs Flipbook Textures

    Renders, composites, and exports flipbook textures.

  • Labs JSON Exporter

    Export geometry attibutes to a JSON file.

  • Labs Marmoset Export

    The Marmoset Export ROP allows you to quickly generate an mview inside Houdini

  • Labs Niagara ROP

    Export point caches to be used with Unreal’s Niagara particle system.

  • Labs Sketchfab

    Uploads geometry to Sketchfab

  • Labs Vertex Animation Textures

    Exports a mesh and a set of textures to be used with a shader for complex real-time effects, such as: soft-body deformation, rigid-body dynamics, dynamically remeshed geometries, and particle sprites.

  • Labs ZibraVDB Compress (Alpha)

    Compresses a VDB sequence and caches it to disk as a single .zibravdb file.

  • 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.

  • 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.

  • USD

    Renders a LOP network out to one or more USD files. This node is available as render node or as a LOP.

  • USD Render

    Renders an output image from the stage generated by a LOP network.

  • USD Stitch

    Merges USD files representing individual frames by composing them.

  • USD Stitch Clips

    Merges multiple value clips representing individual frames.

  • USD Zip

    Assembles USDZ archive files from existing USD files.

  • Wedge

    Re-renders the same ROP multiple times with different settings

  • Wren

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

  • glTF