=================================================================== Partio - A library for particle IO and manipulation =================================================================== This is the initial source code release of partio a tool we used for particle reading/writing. It started out as an abstraction for the commonalities in particle models (i.e. accessing many attributes associated with an index or entity). Super impatient scons building guide ==================================== $ git clone https://github.com/wdas/partio.git $ cd partio $ scons -j 4 (dist/ will now have your build) Getting Started ============== I support both scons and cmake build files. I would rather not support more. Lately I have been using cmake more, so that may be more up to date, but others have contributed fixes from time to time. Source code overview ==================== src/ lib/ Library code (public API in root) lib/core Core library (KDtree traversal, data representations) lib/io Input/Output (Different file formats) py/ SWIG based python bindings doc/ Doxygen documentation and (the start of) a manual tests/ Start of regression tests (I need more) tools/ Useful tools partconv <input format> <output format> partinfo <particle file> partview <particle file> Class Model ----------- The goal of the library is to abstract the particle interface from the data representation. That is why Partio represents particles using three classes that inherit and provide more functionality ParticlesInfo - Information about # of particles and attributes ParticlesData - Read only access to all particle data ParticlesDataMutable - Read/write access to all particle data The functions used to get particle access are these: readHeaders() returns ParticlesInfo reads only the minimum data necessary to get number of particles and attributes readCached() returns ParticlesData For multiple users in different threads using the same particle file ParticlesData create() and read() returns ParticlesDataMutable allows read/write access Behind the scenes you could implement these classes however you like. Headers only representation is called core/ParticleHeader.{h,cpp}. Simple non-interleaved attributes is core/ParticleSimple.{h,cpp}. Attribute Data Model -------------------- All particles have the same data attributes. They have the model that they are of three basic types with a count of how many scalar values they have. VECTOR[3] FLOAT[d] INT[d] VECTOR[3] and FLOAT[3] have the same data representations. VECTOR[4] is invalid however FLOAT[4] is valid as is FLOAT[1...infinity] This seems to encompass the most common file formats for particles Iterating --------- There are multiple ways to access data in the API. Here are some tips - Use SIMD functions when possible prefer dataAsFloat(),data(arrayOfIndices) as opposed to data(int singleIndex) which accesses multiple pieces of data at once - Cache ParticleAttributes for quick access instead of calling attributeInfo() over a loop of particles - Use iterators to do linear operations over all particles They are much more optimized than both data() and the dataAsFloat or Backends -------- Behind the scenes there are SimpleParticles, ParticleHeaders, and SimpleParticlesInterleaved. In the future I would like to write a disk-based cached back end that can dynamically only load the data that is necessary. create(), read() and readCached could be augmented to create different structures in these cases. Readers/Writers --------------- New readers and writers can be added in the io/ directory. You simply need to implement the interface ParticlesInfo, ParticlesData and ParticlesDataMutable (or as many as you need). Editing the io/readers.h to add prototypes and io/ParticleIO.cpp to add file extension bindings should be easy. - Andrew Selle, Walt Disney Animation Studios
MercenariesEngineering/partio
C++ (with python bindings) library for easily reading/writing/manipulating common animation particle formats such as PDB, BGEO, PTC. See the discussion group @ http://groups.google.com/group/partio-discuss
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