bevy/crates/bevy_fbx/README.md
2025-07-13 00:26:42 +08:00

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# Bevy FBX
A Bevy plugin for loading FBX files using the [ufbx](https://github.com/ufbx/ufbx) library.
## Features
-**Mesh Loading**: Load 3D meshes with vertices, normals, UVs, and indices
-**Material Support**: Enhanced PBR material loading with texture application
-**Texture Application**: Automatic application of textures to StandardMaterial
- Base color (diffuse) textures
- Normal maps
- Metallic/roughness textures
- Emission textures
- Ambient occlusion textures
-**Skinning Data**: Complete skinning support with joint weights and inverse bind matrices
-**Node Hierarchy**: Basic scene graph support
- ⚠️ **Animations**: Framework in place, temporarily disabled due to ufbx API compatibility
## Usage
### Enable the Feature
FBX support is an optional feature in Bevy. Add it to your `Cargo.toml`:
```toml
[dependencies]
bevy = { version = "0.16", features = ["fbx"] }
```
### Loading FBX Files
```rust
use bevy::prelude::*;
use bevy::fbx::FbxAssetLabel;
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
// Load an FBX file
let fbx_handle: Handle<bevy::fbx::Fbx> = asset_server.load("models/my_model.fbx");
// Spawn the FBX scene
commands.spawn(SceneRoot(fbx_handle));
}
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.run();
}
```
### Accessing Individual Assets
```rust
use bevy::fbx::{Fbx, FbxAssetLabel};
fn access_fbx_assets(
fbx_assets: Res<Assets<Fbx>>,
fbx_handle: Handle<Fbx>,
) {
if let Some(fbx) = fbx_assets.get(&fbx_handle) {
// Access meshes
for mesh_handle in &fbx.meshes {
println!("Found mesh: {:?}", mesh_handle);
}
// Access materials
for material_handle in &fbx.materials {
println!("Found material: {:?}", material_handle);
}
// Access skins (for skeletal animation)
for skin_handle in &fbx.skins {
println!("Found skin: {:?}", skin_handle);
}
// Access animation clips
for animation_handle in &fbx.animation_clips {
println!("Found animation: {:?}", animation_handle);
}
}
}
```
## Asset Labels
You can load specific parts of an FBX file using asset labels:
```rust
// Load a specific mesh by index
let mesh: Handle<Mesh> = asset_server.load("model.fbx#Mesh0");
// Load a specific material by index
let material: Handle<StandardMaterial> = asset_server.load("model.fbx#Material0");
// Load a specific skin by index
let skin: Handle<bevy::fbx::FbxSkin> = asset_server.load("model.fbx#Skin0");
// Load a specific animation by index
let animation: Handle<AnimationClip> = asset_server.load("model.fbx#Animation0");
```
## Supported FBX Features
- **Geometry**: Triangulated meshes with positions, normals, UVs
- **Materials**: Enhanced PBR properties with automatic texture application
- Base color, metallic, roughness, emission values
- Automatic extraction from FBX material properties
- **Textures**: Complete texture support with automatic application to StandardMaterial
- Base color (diffuse) textures → `base_color_texture`
- Normal maps → `normal_map_texture`
- Metallic textures → `metallic_roughness_texture`
- Roughness textures → `metallic_roughness_texture`
- Emission textures → `emissive_texture`
- Ambient occlusion textures → `occlusion_texture`
- **Skinning**: Joint weights, indices, and inverse bind matrices
- **Hierarchy**: Node transforms and basic parent-child relationships
## Limitations
- **Animations**: Framework in place but temporarily disabled due to ufbx API compatibility
- **Complex Materials**: Advanced material features beyond PBR are not supported
- **FBX-Specific Features**: Some proprietary FBX features may not be available
- **Performance**: Large files may have performance implications during loading
- **Texture Formats**: Only common image formats supported by Bevy are loaded
## Examples
See `examples/3d/load_fbx.rs` for a complete example of loading and displaying FBX files.
## Technical Details
This plugin uses the [ufbx](https://github.com/ufbx/ufbx) library, which provides:
- Fast and reliable FBX parsing
- Support for FBX versions 6.0 and later
- Memory-safe C API with Rust bindings
- Comprehensive geometry and animation support
The plugin follows Bevy's asset loading patterns and integrates seamlessly with the existing rendering pipeline.