Scene management

A “scene” in jackdaw is one .jsn file. A “project” is a folder with a .jsn/project.jsn config file (legacy projects keep it at the root), an assets/ directory, and a Cargo.toml if you scaffolded with the static template. Scenes live under assets/.

Save and load

• Ctrl+S saves the current scene to its on-disk path. The first save prompts for a path; pick something under assets/.
• Ctrl+O opens a scene from disk. The picker starts in the current project’s assets/ folder.
• Ctrl+Shift+N creates a new empty scene in memory; it is unsaved until you Ctrl+S it.

The format details are in JSN Format. The short version: human-readable, line-diffable, and designed to read in git diff without making you cry.

Project select screen

The launcher (AppState::ProjectSelect) is the first thing you see when you run jackdaw with no arguments. It shows:

• Recent projects, with timestamp and last-opened scene.
• A + New Project button for the scaffolds.
• A + New Extension and + New Game button if you want to start an extension or game crate.

Recent projects with missing folders are filtered out (we fixed this in #222). Click a project to open it; the editor transitions into AppState::Editor and reads the project’s default scene.

Default scene per project

.jsn/project.jsn carries a default_scene field. When set, the editor opens that scene automatically when you load the project. If unset, the launcher tries assets/scene.jsn as the convention; if that’s missing too, you start in an empty viewport and Ctrl+O from there.

You can change the default from the file menu or by editing the file directly. The editor watches the file, so external edits show up without a restart.

Multi-scene projects

Nothing stops you from putting many .jsn files in assets/scenes/. The editor doesn’t currently have a “scene list” panel, so you switch between them via File > Open.

If you reference one scene from another (sub-scenes, prefabs), that pattern is not built yet. Today scenes are flat. See Open Challenges for what scene-as-asset would look like.

Project files outside assets/

The editor only watches assets/. Code lives next to it (src/, bin/), and Bevy’s runtime asset path points at assets/. If you put a .jsn somewhere else, jackdaw can load it with File > Open, but the standalone binary won’t find it via Bevy’s asset server.

Common gotchas

• Scene loaded but the viewport is empty. Camera might be inside geometry. Press F with nothing selected (or with a known-visible entity selected) to reframe.
• File > Save greys out. No scene is open. Either File > New Scene or open one from the launcher.
• Saved file has a weird path. First save from a “New Scene” defaults to the project’s assets/scene.jsn. If you want a different path, use File > Save As.