Quickstart (Flutter)
You can find the entire project below in the flutter/quickstart folder of the
thermion_examplesrepository.
- Switch to Flutter master channel, upgrade Flutter, create a new project, then add
thermion_flutteras a dependency
$ flutter channel master
$ flutter upgrade
$ flutter config --enable-native-assets
$ flutter create thermion_sample_project && cd thermion_sample_project
$ flutter pub add thermion_flutter
- If running on iOS or MacOS, change the minimum deployment target to OSX 13
- Add a folder containing your assets (glTF model + skybox ktx) to your
pubspec.yamlasset list
...
flutter
uses-material-design: true
assets:
- assets/
- Create an instance of
ThermionFlutterPluginin your app.
class _MyAppState extends State<MyApp> {
late ThermionFlutterPlugin _thermionFlutterPlugin;
late Future<ThermionViewer> _thermionViewer;
void initState() {
_thermionFlutterPlugin = ThermionFlutterPlugin();
_thermionViewer = _thermionFlutterPlugin.createViewer();
}
}
- Add a
ThermionWidgetto your widget hierarchy
class _MyAppState extends State<MyApp> {
ThermionViewer? _thermionViewer;
void initState() {
_thermionFlutterPlugin.createViewer().then((viewer) {
setState(() {
_thermionViewer = viewer;
});
});
}
Widget build(BuildContext context) {
return Stack(children:[
if(_thermionViewer != null)
Positioned.fill(
child:ThermionWidget(
plugin:_thermionViewer!
)
)
]);
}
}
- Add a button to load the model when pressed
...
class _MyAppState extends State<MyApp> {
...
bool _loaded = false;
Widget build(BuildContext context) {
return Stack(children:[
if(_thermionViewer != null)
Positioned.fill(
child:ThermionWidget(
plugin:_thermionViewer!
)
),
if (!_loaded)
Center(
child: ElevatedButton(
child: const Text("Load"),
onPressed: () async {
// TODO
_loaded = true;
setState(() {});
}))
]);
}}
- When the button is pressed, load a skybox, lighting and the glb asset
You will need to import the dart:math and package:vector_math libraries.
import 'package:vector_math/vector_math_64.dart' as v;
import 'dart:math';
...
class _MyAppState extends State<MyApp> {
...
Widget build(BuildContext context) {
return Stack(children:[
...
if(!_loaded)
Center(
child: ElevatedButton(
child: const Text("Load"),
onPressed: () async {
var viewer = await _thermionViewer;
await viewer.loadIbl("assets/default_env_ibl.ktx");
await viewer.loadSkybox("assets/default_env_skybox.ktx");
await viewer.loadGlb("assets/cube.glb");
await viewer.setCameraPosition(0, 1, 10);
await viewer.setCameraRotation(v.Quaternion.axisAngle(
v.Vector3(1, 0, 0), -30 / 180 * pi) *
v.Quaternion.axisAngle(v.Vector3(0, 1, 0), 15 / 180 * pi));
await viewer.addLight(
LightType.SUN, 7500, 50000, 0, 0, 0, 1, -1, -1);
await viewer.setRendering(true);
_loaded = true;
setState(() {});
}
)
)
]);
}
}
Here, we've added a skybox (the background (cube) image rendered behind all other elements in the scene), image-based lighting (where an image is used to determine the direction and intensity of a light source) and a directional light (Sun).
Anything added to the scene is referred to as an "entity" (including lights and cameras).
Entities are always added to the scene at position (0,0,0).
The default scene camera is located at (0,0,0) (and is looking at -Z, or "into" the screen), so by adding a cube at (0,0,0), the camera will now be inside the cube.
We need to move the camera outside the cube so it's visible.
- Change the camera orientation
var viewer = await _thermionViewer;
await viewer.loadSkybox("assets/default_env_skybox.ktx");
await viewer.loadGlb("assets/cube.glb");
await viewer.setCameraPosition(0, 1, 10);
await viewer.setCameraRotation(v.Quaternion.axisAngle(
v.Vector3(1, 0, 0), -30 / 180 * pi) *
v.Quaternion.axisAngle(v.Vector3(0, 1, 0), 15 / 180 * pi));
The cube still won't be visible until we add a light to the scene and tell Thermion to start rendering.
- Add a light and turn rendering on
...
await viewer.addLight(
LightType.SUN, 7500, 50000, 0, 0, 0, 1, -1, -1);
await viewer.setRendering(true);
...
- Run the project
$ flutter run -d macos
You may experience a noticeable delay the very first time you run the project. Don't panic, it's not frozen! This is due to the build system downloading the prebuilt Filament binaries from Cloudflare, which can take some time (particularly on Windows). These binaries will be cached after first download, so subsequent runs will be much faster (though every time you run flutter clean, the binaries will be re-downloaded).
Your first Thermion project is complete!