Developers

This section is information about the Addon and .edm file format that you only need if you want to work directly in some way with the addon code or interpreting the file yourself.

Source code is available on Github, at https://github.com/ndevenish/Blender_ioEDM. Current development may be on master, or may be on a specific working branch, depending on what is currently in progress.

Notes on development:

• There is a read.py file that can be used to launch blender with an instant import, to be used e.g. blender –python read.py – edmfile.EDM. This makes the cycle of change/debug/rewrite more manageable
• There is also a write.py. Use as blender <filename>.blend –python write.py and the writer will be run on the contents of the loaded blender file.
• Several useful scripts in utils. read_all.py reads every .edm file in an all_edms/ subdirectory (useful itself as a verification), removes the raw vertex and index data, and pickles the entire result into dump.dat. The script read_dump.py opens this file, defines some useful functions and then opens an interpreter (with the local variable data). This allows inspection of a large subset (or every single .edm file) simultaneously.
• All of the file->Blender conversion is done in io_EDM.reader, and most of the actual functionality is currently in one large function, create_object
• All parsing of the binary data is done in the io_EDM.edm sub-package, and is at time of writing separate from Blenders API - although if the API is available, the bpy.mathutils module is used for Vector/Matrix/Quaternion representations. Most of the edm-specific reading is done in io_EDM.edm.types module, starting with the EDMFile class __init__.
• A summary of the knowledge gained about the .EDM file format can be found in the EDM_Specification.md file also located in this repository.

In addition, there are several unanswered questions regarding the contents of the edm file, including:

• Exactly how are the animation transformations applied, and the purpose of the ‘second quaternion’ in the ArgAnimationNode common base data
• The interpretation of the material “TEXTURE_COORDINATES_CHANNELS”
• Lots of other details needed on the occasional unknown datablock

• EDM Specification
  • Reading Type definitions
  • Basic types and Structures
  • File-level Structure
  • Named Types
  •  model::RootNode
  • Material
  • Nodes
  •  Animation Nodes
  •  Object Nodes