OpenVDB

OpenVDB is an open-source C++ library and industry standard developed by DreamWorks Animation for the efficient storage and manipulation of sparse, time-varying, volumetric data. It represents volumes as hierarchical collections of voxel blocks, allowing for highly compressed and scalable representations of complex data such as smoke, fire, clouds, and other volumetric effects.

The core concept behind OpenVDB is the combination of a sparse voxel grid structure with a tree-like hierarchy. This allows for storing data only where it is needed, eliminating the memory overhead associated with dense volumetric grids, particularly when dealing with large-scale and highly detailed simulations. The tree structure allows for varying levels of detail (LODs) and adaptive refinement, improving performance and memory usage during processing and rendering.

OpenVDB provides tools for a wide range of operations on volumetric data, including filtering, resampling, level set operations, and boolean operations. It also supports various data types, such as floats, vectors, and matrices, allowing for the representation of different attributes associated with the volume.

The library is widely used in visual effects (VFX), animation, and scientific visualization for managing and processing volumetric data. Its efficient memory usage and flexible data structures make it a powerful tool for creating complex and realistic simulations. OpenVDB is actively maintained and extended, with contributions from both DreamWorks and the open-source community. Its standardized format allows for interoperability between different software packages and rendering engines commonly used in the industry. The library integrates readily with popular tools like Houdini, Maya, and Blender.