The six lighting models: the source

since 0.1.0 Shading and materials
Open the live demo · Read the guide · View on GitHub
Regions the guide quotes: models (line 28), row (line 38), light (line 50), live (line 58).
1/// The six lighting models the engine ships, one sphere each.
2///
3/// Quoted by `lighting_models.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 LightingModelsDemo extends ShowcaseDemo {
double roughness = 0.4;
double sunIntensity = 3.0;

late final List<Material> _materials;
late final LightNode _sun;

@override
void configureView(DemoContext context) {
  context.orbit
    ..distance = 5.6
    ..pitch = 0.2
    ..yaw = 0.0
    ..apply();
}

@override
Scene build(DemoContext context) {
  _materials = <Material>[
    for (final LightingModel model in LightingModel.builtIn)
      Material(
        name: model.label,
        lighting: model,
        baseColor: Vector4(0.85, 0.45, 0.3, 1.0),
        roughness: roughness,
      ),
  ];

  final DeviceMesh sphere = DeviceMesh.upload(
    context.device,
    const SphereShape(segments: 40, rings: 20).build(),
  );
  final Scene scene = Scene();
  for (var i = 0; i < _materials.length; i++) {
    scene.add(
      MeshNode(sphere, _materials[i], name: _materials[i].name)
        ..setPosition((i % 3 - 1) * 1.35, i < 3 ? 0.7 : -0.7, 0.0),
    );
  }

  _sun = LightNode(name: 'sun', intensity: sunIntensity)
    ..setLocalForward(Vector3(-0.4, -0.6, -0.7));
  scene.add(_sun);
  return scene;
}

@override
void update(DemoContext context, double dt) {
  for (final Material material in _materials) {
    material.roughness = roughness;
  }
  _sun.intensity = sunIntensity;
}

@override
List<DemoControl> controls(DemoContext context) => <DemoControl>[
  SliderControl(
    'Roughness',
    min: 0.05,
    max: 1,
    value: () => roughness,
    onChanged: (double v) => roughness = v,
  ),
  SliderControl(
    'Sun',
    min: 0,
    max: 6,
    value: () => sunIntensity,
    onChanged: (double v) => sunIntensity = v,
  ),
];

@override
void verify(Scene scene, FrameResult frame) {
  final int models = LightingModel.builtIn.length;
  final FramePass drawn = frame.passes.firstWhere(
    (FramePass pass) => pass.name == 'scene',
  );
  if (drawn.drawCalls != models) {
    throw StateError('${drawn.drawCalls} draws for $models spheres');
  }
  if (drawn.pipelineSwitches != models) {
    throw StateError(
      'the $models models used ${drawn.pipelineSwitches} pipelines; '
      'each model is a shader of its own',
    );
  }
}
98}