Reflection probes: the source

since 0.4.3 Light and environment
Open the live demo · Read the guide · View on GitHub
Regions the guide quotes: ball (line 44), probe (line 51), live (line 98).
1/// A mirror finish that shows the room it stands in, not the sky: a cube
2/// captured from one point and convolved into a roughness chain on the
3/// device.
4///
5/// Quoted by `reflection_probes.md` and shown whole in the Source tab.
6library;

8import 'dart:math' as math;

10import 'package:flutter3d/flutter3d.dart';
11import 'package:flutter3d_showcase/src/demo/demo.dart';
12import 'package:vector_math/vector_math.dart';

14final class ReflectionProbesDemo extends ShowcaseDemo {
double intensity = 1.0;
double roughness = 0.06;

late final ReflectionProbeNode _probe;
late final Material _ball;

@override
void configureView(DemoContext context) {
  context.orbit
    ..distance = 6.0
    ..pitch = 0.18
    ..yaw = 0.7;
  context.orbit.target.setValues(0.0, 0.7, 0.0);
}

@override
Scene build(DemoContext context) {
  final Material floor = Material(
    name: 'floor',
    baseColor: Vector4(0.5, 0.5, 0.53, 1.0),
    roughness: 0.9,
    doubleSided: true,
  );
  final Material wall = Material(
    name: 'wall',
    baseColor: Vector4(0.82, 0.18, 0.14, 1.0),
    roughness: 0.9,
    doubleSided: true,
  );
  final Material ball = _ball = Material(
    name: 'mirror ball',
    baseColor: Vector4(0.9, 0.9, 0.92, 1.0),
    metallic: 1.0,
    roughness: roughness,
  );

  _probe = ReflectionProbeNode(name: 'probe', intensity: intensity)
    ..setPosition(0.0, 0.9, 0.0);

  final MeshNode wallNode =
      MeshNode(
          DeviceMesh.upload(
            context.device,
            const PlaneShape(width: 3, depth: 4).build(),
          ),
          wall,
          name: 'wall',
        )
        ..setPosition(-2.0, 1.5, 0.0)
        ..setRotation(
          Quaternion.axisAngle(Vector3(0.0, 0.0, 1.0), -math.pi / 2),
        );

  return Scene()
    ..ambientIntensity = 0.15
    ..add(
      MeshNode(
        DeviceMesh.upload(
          context.device,
          const PlaneShape(width: 8, depth: 8).build(),
        ),
        floor,
        name: 'floor',
      ),
    )
    ..add(wallNode)
    ..add(
      MeshNode(
        DeviceMesh.upload(
          context.device,
          SphereShape(radius: 0.9, segments: 32, rings: 16).build(),
        ),
        ball,
        name: 'ball',
      )..setPosition(0.0, 0.9, 0.0),
    )
    ..add(
      LightNode(name: 'sun', intensity: 3.0)
        ..setLocalForward(Vector3(-0.5, -0.7, -0.35)),
    )
    ..add(_probe);
}

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

@override
List<DemoControl> controls(DemoContext context) => <DemoControl>[
  SliderControl(
    'Probe intensity',
    min: 0,
    max: 2,
    value: () => intensity,
    onChanged: (double v) => intensity = v,
  ),
  SliderControl(
    'Ball roughness',
    min: 0.02,
    max: 1,
    value: () => roughness,
    onChanged: (double v) => roughness = v,
  ),
];

@override
void verify(Scene scene, FrameResult frame) {
  if (!_probe.isCaptured) {
    throw StateError('the probe never finished capturing its cube');
  }
  final FramePass capture = frame.passes.firstWhere(
    (FramePass p) => p.name == 'reflection probe 0',
    orElse: () => throw StateError('no reflection probe pass ran this frame'),
  );
  if (capture.drawCalls == 0) {
    throw StateError('the probe pass ran and drew nothing into its cube');
  }
}
135}