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| Since | 20.5 |
As a part of the ZibraVDB for Houdini 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.
Tip
You can force the compression and decompression to run on CPU instead of GPU via an environment variable:
ZIBRAVDB_FOR_HOUDINI_FORCE_SOFTWARE_DEVICE = 1
On Windows, you can force the choice of graphics API via an environment variable:
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ZIBRAVDB_FOR_HOUDINI_FORCE_GRAPHICS_API = D3D12 -
ZIBRAVDB_FOR_HOUDINI_FORCE_GRAPHICS_API = VULKAN
Getting Ready ¶
Download ZibraVDB Core Library ¶
The plugin 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).
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Click the Open Plugin Management button on any ZibraVDB node. A pop-up window will appear.
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Click the Download Library button. You will be redirected to a ZibraVDB for Houdini webpage.
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Download the ZibraVDB Compression Library from the webpage.
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Unpack the contents of the archive into the Houdini user preference directory:
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On Windows, the default location is
%userprofile%/documents/houdiniX.Y. -
On Linux, the default location is
$HOME/houdiniX.Y.
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Return to Houdini and click the Load Library button in the Plugin Management window. You should now see the Library status as “Loaded”, along with the library version.
Install to HSITE
To copy the ZibraVDB Compression Library to HSITE for site-wide installation, click the Copy Library to HSITE button in the Plugin Management window and follow on-screen prompts.
Install to HQueue
To copy the ZibraVDB Compression Library to HQROOT to make it available on HQueue nodes, click the Copy Library to HQROOT button in the Plugin Management window and follow on-screen prompts.
Acquire License Key ¶
There are 5 free compressions before you need to purchase a license key to continue using the plugin.
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Purchase a license key on the Zibra AI website.
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Open Houdini and click the Open Plugin Management button on any ZibraVDB node.
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Enter your license key string (not the file path) in the License key field.
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Click the Set License Key button. You should now see Activation status as “Activated”.
Activation using an environment variable
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Create a text file in a directory of your choice and name it
zibravdb_license_key.txt. Paste your license key into this text file and save it. -
Set up a Houdini environment variable named
ZIBRAVDB_LICENSE_KEYand 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
Please do not include the # at the beginning of a line. The # comments the line out.
You may also use the package mechanism to set environment variables.
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.
Open Plugin Management
Opens the Plugin Management window to view the plugin’s info, manage core library, and configure license.
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.
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