Point and spot shadows: the source

since 0.2.0 Shadows
Open the live demo · Read the guide · View on GitHub
Regions the guide quotes: lamp (line 86), spot (line 96), settings (line 114).
1/// Shadows from a lamp and from a spotlight, drawn into a cube map.
2///
3/// Quoted by `point_light_shadows.md` and shown whole in the Source tab.
4library;

6import 'package:flutter3d/flutter3d.dart';
7import 'package:flutter3d_showcase/src/demo/demo.dart';
8import 'package:vector_math/vector_math.dart';

10final class PointLightShadowsDemo extends ShowcaseDemo {
double softness = 4.0;
double bias = 0.08;
int sizeChoice = 1;
int facesChoice = 1;

static const List<int> _sizes = <int>[128, 256, 512];
static const List<ShadowCasterFaces> _faces = <ShadowCasterFaces>[
  ShadowCasterFaces.front,
  ShadowCasterFaces.back,
  ShadowCasterFaces.both,
];

@override
void configureView(DemoContext context) {
  context.orbit
    ..distance = 9.0
    ..pitch = 0.55
    ..yaw = 0.7;
}

@override
Scene build(DemoContext context) {
  final Material stone = Material(
    name: 'stone',
    baseColor: Vector4(0.78, 0.76, 0.72, 1.0),
    roughness: 0.9,
  );
  final Material floorStone = stone.copy()..doubleSided = true;
  final Material clay = Material(
    name: 'clay',
    baseColor: Vector4(0.85, 0.45, 0.3, 1.0),
    roughness: 0.7,
  );
  final Scene scene = Scene()
    ..add(
      MeshNode(
        DeviceMesh.upload(
          context.device,
          const PlaneShape(width: 12, depth: 12).build(),
        ),
        floorStone,
        name: 'floor',
      ),
    )
    ..add(
      MeshNode(
        DeviceMesh.upload(
          context.device,
          CuboidShape(size: Vector3(12.0, 4.0, 0.3)).build(),
        ),
        stone,
        name: 'wall',
      )..setPosition(0.0, 2.0, -5.0),
    )
    ..add(
      MeshNode(
        DeviceMesh.upload(
          context.device,
          CuboidShape(size: Vector3(1.0, 2.0, 1.0)).build(),
        ),
        clay,
        name: 'column',
      )..setPosition(-1.0, 1.0, -1.0),
    )
    ..add(
      MeshNode(
        DeviceMesh.upload(
          context.device,
          SphereShape(radius: 0.7, segments: 24, rings: 12).build(),
        ),
        clay,
        name: 'ball',
      )..setPosition(1.8, 0.7, -2.0),
    );

  scene.add(
    LightNode(
      name: 'lamp',
      type: LightType.point,
      intensity: 50.0,
      range: 16.0,
      castsShadow: true,
    )..setPosition(1.5, 3.2, 1.0),
  );

  scene.add(
    LightNode(
        name: 'spot',
        type: LightType.spot,
        intensity: 90.0,
        range: 16.0,
        innerConeAngle: 0.2,
        outerConeAngle: 0.5,
        castsShadow: true,
      )
      ..setPosition(-4.0, 3.5, 3.5)
      ..lookAt(Vector3(-1.0, 0.5, -1.5)),
  );
  return scene;
}

@override
RenderSettings settings(DemoContext context) => RenderSettings(
  shadows: ShadowSettings(
    cubeResolution: _sizes[sizeChoice],
    pointBias: bias,
    pointSoftness: softness,
    casterFaces: _faces[facesChoice],
  ),
);

@override
List<DemoControl> controls(DemoContext context) => <DemoControl>[
  SliderControl(
    'Softness',
    min: 0,
    max: 16,
    value: () => softness,
    onChanged: (double v) => softness = v,
    format: (double v) => '${v.toStringAsFixed(1)} texels',
  ),
  SliderControl(
    'Bias',
    min: 0,
    max: 0.5,
    value: () => bias,
    onChanged: (double v) => bias = v,
    format: (double v) => '${v.toStringAsFixed(2)} m',
  ),
  ChoiceControl(
    'Face size',
    options: <String>[for (final int s in _sizes) '$s'],
    index: () => sizeChoice,
    onChanged: (int i) => sizeChoice = i,
  ),
  ChoiceControl(
    'Casters draw',
    options: const <String>['Front', 'Back', 'Both'],
    index: () => facesChoice,
    onChanged: (int i) => facesChoice = i,
  ),
];

@override
void verify(Scene scene, FrameResult frame) {
  if (!frame.passes.any((FramePass p) => p.name == 'point shadows')) {
    throw StateError('no cube shadow pass ran');
  }
  if (frame.shadowsDenied > 0) {
    throw StateError(
      '${frame.shadowsDenied} light(s) asked for a shadow and were refused',
    );
  }
}
165}