Particles are an important part of effects work, because they allow free-form information in 3D space. Unfortunately, there is no standard format for particles akin to Wavefront .obj. Most animation systems have their own proprietary particle formats. For example Maya uses the binary and ascii particle database formats .pdb and .pda file formats. Houdini uses the .geo and .bgeo geometry uber formats. Renderers typically have their own point cloud format such as RenderMan’s PTC format and Houdini’s .pc. All of these formats share a common theme. They allow particles to be iterated or indexed and associate a customizable set of attributes with them. The goal of Partio is to provide a unified interface akin to unified image libraries that makes it easier to load, save, and manipulate particle files.

Home Page: http://www.disneyanimation.com/technology/partio.html
Project Page: https://github.com/wdas/partio
Language: C++ Python
Platform: Linux, OSX, Windows
License: New BSD
Sponsor: Walt Disney Animation Studios