Houdini 20.5 Nodes Geometry nodes

Labs ZibraVDB Compress (Alpha) 0.2 geometry 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.

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

Geometry nodes