Introduction

Jackdaw is a 3D level editor built with Bevy. It does brush-based geometry, material and texture management, heightmap terrain, and a human-readable scene format (.bsn). Your project stays a normal Bevy crate: the editor builds and plays the same cargo binary you run from a terminal, so cargo build and cargo run keep compiling plain crates.io Bevy with nothing jackdaw-specific forced into the manifest.

We are pre-1.0. Things change. Some pieces are still in active flux, and this book tries to call out what is solid versus what is in flight.

What you can do today

• Author levels by drawing brushes, carving them with boolean operations, and applying materials.
• Build heightmap terrain with sculpt and erosion tools.
• Add Bevy-reflect components to entities through a picker, edit their fields, and see your custom components round- trip through save/load.
• Load the same scene in a standalone Bevy binary through jackdaw_runtime, with no editor in the dependency graph.
• Play the game from inside the editor, out of process, with live frames streamed into a panel.
• Write extensions in plain Rust that plug into the editor’s operator and panel system.

Who this is for

Two audiences:

• Bevy developers who want a level editor for their game and don’t want to glue something together themselves.
• Editor / tooling developers who want to build on top of a pluggable Bevy editor.

If you have used a brush-based level editor before, the geometry model will feel familiar: convex volumes carved and combined in place rather than meshes imported from a modelling tool. If you have used a scene editor, .bsn files play the same role as its scene files, except they are plain text you can read and diff.

What this book covers

• Getting Started: install, scaffold a project, save a scene, or bring an existing Bevy game in.
• User Guide: the panels and tools you actually click on.
• Developer Guide: how the editor is put together, how to write custom components, how to extend the editor with your own operators and windows.
• Reference: configuration, file paths.
• Open Challenges lists what we have not built yet but want to. If you came here looking for something to hack on, start there.

Where to find us

• Discord: discord.gg/S9k2HRwc. The fastest way to ask a question or share a screenshot.
• GitHub: jbuehler23/jackdaw. Source, issue tracker, and this book (under book/).

Bug reports are most useful with the scene file, the steps that reproduced the problem, and what you expected instead.

If you find a missing page or an instruction that doesn’t match what the editor does, the book lives at book/ in the repo. PRs welcome.