Screen-space reflections: the source

since 0.2.0 Post-processing
Open the live demo · Read the guide · View on GitHub
Regions the guide quotes: floor (line 28), beacon (line 42), settings (line 72), ran (line 95).
1/// Screen-space reflections: a ray marched through the picture the scene
2/// already drew, so a polished floor shows what stands on it.
3///
4/// Quoted by `screen_space_reflections.md` and shown whole in the Source tab.
5library;

7import 'package:flutter3d/flutter3d.dart';
8import 'package:flutter3d_showcase/src/demo/demo.dart';
9import 'package:vector_math/vector_math.dart';

11final class ScreenSpaceReflectionsDemo extends ShowcaseDemo {
double roughness = 0.05;
double intensity = 1.0;

late final Material _floor;

@override
void configureView(DemoContext context) {
  context.orbit
    ..distance = 5.0
    ..pitch = 0.28
    ..yaw = 0.5;
  context.orbit.target.setValues(0.0, 0.3, 0.0);
}

@override
Scene build(DemoContext context) {
  _floor = Material(
    name: 'floor',
    baseColor: Vector4(0.06, 0.06, 0.07, 1.0),
    roughness: roughness,
  );
  final MeshNode floorMesh = MeshNode(
    DeviceMesh.upload(
      context.device,
      CuboidShape(size: Vector3(10.0, 0.3, 10.0)).build(),
    ),
    _floor,
    name: 'floor',
  );

  final MeshNode beacon = MeshNode(
    DeviceMesh.upload(
      context.device,
      CuboidShape(size: Vector3.all(1.0)).build(),
    ),
    Material(
      name: 'beacon',
      baseColor: Vector4(0.0, 0.0, 0.0, 1.0),
      emissive: Vector3(1.0, 0.4, 0.1),
      emissiveStrength: 2.0,
    ),
    name: 'beacon',
  )..setPosition(0.0, 0.65, 0.0);

  return Scene()
    ..add(floorMesh)
    ..add(beacon)
    ..add(
      LightNode(name: 'sun', intensity: 1.0)
        ..setLocalForward(Vector3(-0.4, -1.0, -0.3)),
    );
}

@override
void update(DemoContext context, double dt) {
  _floor.roughness = roughness;
}

@override
RenderSettings settings(DemoContext context) => RenderSettings(
  reflections: ReflectionSettings(enabled: true, intensity: intensity),
);

@override
List<DemoControl> controls(DemoContext context) => <DemoControl>[
  SliderControl(
    'Roughness',
    min: 0.02,
    max: 0.4,
    value: () => roughness,
    onChanged: (double v) => roughness = v,
  ),
  SliderControl(
    'Intensity',
    min: 0,
    max: 1.5,
    value: () => intensity,
    onChanged: (double v) => intensity = v,
  ),
];

@override
void verify(Scene scene, FrameResult frame) {
  if (!frame.passes.any((FramePass p) => p.name == 'reflections')) {
    throw StateError('the reflections pass did not run: ${frame.skipped}');
  }
}
99}