Depth of field: the source

since 0.7.0 Post-processing
Open the live demo · Read the guide · View on GitHub
Regions the guide quotes: row (line 27), lens (line 53), ran (line 91).
1/// Depth of field from a thin lens: a focus distance, a focal length and an
2/// f-number, the same three numbers a photographer already knows.
3///
4/// Quoted by `depth_of_field.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 DepthOfFieldDemo extends ShowcaseDemo {
double focusDistance = 4.0;
double aperture = 2.0;
double focalLength = 0.085;

@override
void configureView(DemoContext context) {
  context.orbit
    ..distance = 4.0
    ..pitch = 0.0
    ..yaw = 0.0;
  context.orbit.target.setValues(0.0, 0.0, -4.0);
}

@override
Scene build(DemoContext context) {
  final Scene scene = Scene();
  final DeviceMesh post = DeviceMesh.upload(
    context.device,
    CuboidShape(size: Vector3(0.4, 1.6, 0.4)).build(),
  );
  for (var i = 0; i < 6; i++) {
    final double z = -1.0 - i * 2.0;
    scene.add(
      MeshNode(
        post,
        Material(
          name: 'post $i',
          baseColor: Vector4(0.85, 0.4 + i * 0.08, 0.2, 1.0),
        ),
        name: 'post $i',
      )..setPosition(0.0, 0.0, z),
    );
  }
  return scene..add(
    LightNode(name: 'sun', intensity: 3.0)
      ..setLocalForward(Vector3(-0.3, -0.7, -0.4)),
  );
}

@override
RenderSettings settings(DemoContext context) => RenderSettings(
  depthOfField: DepthOfFieldSettings(
    enabled: true,
    focusDistance: focusDistance,
    focalLength: focalLength,
    aperture: aperture,
  ),
);

@override
List<DemoControl> controls(DemoContext context) => <DemoControl>[
  SliderControl(
    'Focus distance',
    min: 1,
    max: 11,
    value: () => focusDistance,
    onChanged: (double v) => focusDistance = v,
    format: (double v) => '${v.toStringAsFixed(1)} m',
  ),
  SliderControl(
    'Aperture (f/)',
    min: 1.4,
    max: 16,
    value: () => aperture,
    onChanged: (double v) => aperture = v,
    format: (double v) => v.toStringAsFixed(1),
  ),
  SliderControl(
    'Focal length',
    min: 0.024,
    max: 0.135,
    value: () => focalLength,
    onChanged: (double v) => focalLength = v,
    format: (double v) => '${(v * 1000).round()} mm',
  ),
];

@override
void verify(Scene scene, FrameResult frame) {
  if (!frame.passes.any((FramePass p) => p.name == 'depth of field')) {
    throw StateError('the depth of field pass did not run: ${frame.skipped}');
  }
}
95}