Welcome to Ragdoll! This addon is a "bridge" between Blender and "Ragdoll Core", which is the run-time engine and API of Ragdoll.
Under the hood, Ragdoll is similar to Blender and Maya, in that it also has a notion of objects, a scene graph, selection, undo and redo, a serialisation format for saving scene files to disk. The basic building blocks of a graphical editor.
Any change made interactively is made via a so-called "Operator".
Operators are Blender's way of encapsulating an action with undo/redo, along with modal edits such as activating a picker and picking a mesh to replace a collider with.
All of Ragdoll's operators live in the operators/ directory and registerd to the namespace bpy.ops.ragdoll.
# Select some objects, and run the following:
bpy.ops.ragroll.assign_markers()The glue between Ragdoll and Blender is called "bpx" and is a subset of bpy with persistent references to objects and bones.
from ragdoll.vendor import bpx
obj = bpx.create_object(bpx.e_mesh)References will survive undo and provides caching and change detection of properties.
- See bpx.py for details
As part of ragdoll.vendor.bpx every Object and PoseBone in Blender that Ragdoll operates on will have a bpxId property. This is a persistent identifier that survives undo and redo, which Blender would normally consider destructive to any Python object reference.
Each object representing a Ragdoll "entity" is imbued with a ragdollId property. This property helps Ragdoll identify which objects should have an entity instantiated for it on scene-open.