Preface

This is an unofficial engine developer manual for Panda3D, for those who want to understand, debug, and modify the engine internals, not just use it to make games. (For the user-facing manual, see the official docs at https://docs.panda3d.org.)

The manual is organized in several parts:

  1. Source tree — a developer’s map of the codebase: one entry per directory, saying what it is and where to start reading.

  2. Engine subsystems — source-grounded deep-dives into each major subsystem (audio, dtool, the scene graph, characters & animation, collision & physics, …): the central classes, inheritance, entry points, and gotchas, with cited community context.

  3. Cross-cutting concepts — the foundational patterns every subsystem relies on: the TypeHandle type system, reference counting & PointerTo, BAM serialization, the threaded pipeline cycler, and interrogate Python bindings. Read this first.

  4. File formats & reference — egg-file syntax, the config (PRC) system, render-order/cull bins, the GraphicsEngine, and other reference material. Some of this is older legacy documentation.

  5. Miscellaneous & F.A.Q., and the Appendix.

On currency. Parts 1–3 were re-derived from the Panda3D master branch (the 1.11 development line, post-v1.10.16) and verified against the actual source code. Part 4 retains older material — some of it dates back to the Disney/CMU era (2002 onward) and may describe deprecated APIs; it is kept for its still-useful reference content (egg syntax, PRC, etc.), but treat specific API details there with appropriate suspicion and check against the source.

Primary source of truth. Throughout, the C++/Python source code is the authority. File paths are given relative to the repository root (e.g. panda/src/audio/audioManager.h). When in doubt, read the code.