Bevy_adventure

A framework for building 3d adventure games in Bevy.

Features

• Interactive trait is the backbone of the framework, allowing you to create powerful, dynamic objects in your world that can be interacted with and can affect other objects or global state.
• Scene trait exposes a Plugin-like interface for managing GLTF scenes and assigning components to entities (based on bevy_scene_hook)
• WorldState resource, a stringly-typed storage for tracking progression
• Inventory resource allows you to track held items and create recipes for combining them
• Automatic camera animation and state management, Component-based interface
• Support for multiple scenes (built on top of iyes_loopless)

Examples

There is an elaborate example available at examples/main.rs. Three scenes are included, with multiple objects that can be interacted with or picked up.

Notes

Save States

bevy_adventure intentionally omits implementing save state functionality, as different games will have different requirements.

If you want to implement this, here is what you need to keep track of:

• CurrentSpot resource, which determines your current camera spot in the scene. When saving, save the name of the CameraSpot from this resource. When loading, create a new NextSpot instance from the loaded name, and insert it with Commands.
• CurrentState<State> resource, (from iyes_loopless) which determines what scene is currently loaded
• Inventory resource, which tracks what items the player is holding
• WorldState resource, the global game state storage

You will also have to enable the serde feature to allow serialization and deserialization of these resources.

Using WorldState

When you are building interactives, you have the ability to store information in the component itself or the WorldState.

The component should only hold temporary state information - like which drawer is open on a dresser or if an entity has been spawned.

If you want to store any other kind of information, it should be done in the WorldState resource. This is so other interactives in your scene can access this state (for example, you'd flip a switch and the lights would go out) and so you are storing state information in a single place.

Creating scenes

When implementing the Scene trait, the scene method should return a path to a file that can be loaded with the AssetServer to create a Bevy Scene. In practice this is a GLTF scene file, but any other format can be used as long as it creates a Bevy Scene when loaded.

When imported with bevy_adventure, Cameras are automatically converted to CameraSpots, and PointLights are configured to cast shadows.

The Scene trait's spawn method is called for every Entity in the scene - you can use this to assign components and initialize behavior for objects in your scene. The best way to do this is to match entity Names (from their names in the Scene), see the examples for an idea of how you should do this.

The only real requirement for your scene is that you create a special Camera with the name Camera_Main. This is where your Camera will be positioned upon entering the Scene. The app will panic if a scene is loaded without the Main Camera.

If you have issues matching objects by name, you might be matching the parent instead of the actual object you want to match. Adding a print statement inside of your Scene's spawn method might help you figure out if the object is actually being found.

Note that when you are loading Scenes into Bevy, the 'Transform Scale' of each object is also loaded in. This could cause colliders to be the wrong size - you should 'apply Scale' before exporting.

Object origin is also used loaded in - this could cause misaligned colliders if your object's origin doesn't match the center of your object.

Blender is a good choice to create GLTF scenes, but you must make sure you configure the export settings correctly:

• Under Include, check Custom Properties, Cameras, and Punctual Lights.
• Under Transform, uncheck Y+ Up

TODO

• Audio example
• Save state example

License

bevy_adventure is dual-licensed under MIT and Apache-2.0.

Compatibility

NOTE: We do not track Bevy main.