Specular strength: the source

since 0.1.0 or earlier Shading and materials

Open the live demo · Read the guide · View on GitHub

Regions the guide quotes: material (line 26), light (line 43), settings (line 53), check (line 69).

1/// `RenderSettings.specular`: one scalar that turns the whole frame's
2/// specular response up or down without touching a single material.
3///
4/// Quoted by `specular_scale.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 SpecularScaleDemo extends ShowcaseDemo {
double specular = 1.5;

late final Material _ball;
late final LightNode _sun;

@override
void configureView(DemoContext context) {
  context.orbit
    ..distance = 4.5
    ..pitch = 0.15;
}

@override
Scene build(DemoContext context) {
  _ball = Material(
    name: 'ball',
    lighting: LightingModel.pbr,
    baseColor: Vector4(0.75, 0.2, 0.2, 1.0),
    metallic: 0.9,
    roughness: 0.18,
  );

  final MeshNode ball = MeshNode(
    DeviceMesh.upload(
      context.device,
      SphereShape(segments: 48, rings: 24).build(),
    ),
    _ball,
    name: 'ball',
  );

  _sun = LightNode(name: 'sun', intensity: 3.0)
    ..setLocalForward(Vector3(-0.3, -0.6, -0.7));

  return Scene()
    ..add(ball)
    ..add(_sun);
}

@override
RenderSettings settings(DemoContext context) => RenderSettings(
  specular: specular,
);

@override
List<DemoControl> controls(DemoContext context) => <DemoControl>[
  SliderControl(
    'Specular',
    min: 0,
    max: 3,
    value: () => specular,
    onChanged: (double v) => specular = v,
  ),
];

@override
void verify(Scene scene, FrameResult frame) {
  if (_ball.metallic < 0.5 || _ball.roughness > 0.4) {
    throw StateError('the ball is not shiny enough to show a highlight');
  }
  if (frame.drawCalls < 1) {
    throw StateError('the ball was not drawn');
  }
}
76}