Plan a frame before drawing: the source

since 0.7.0 Scene and geometry
Open the live demo · Read the guide · View on GitHub
Regions the guide quotes: scene (line 26), settings (line 56), plan (line 61), controls (line 76), check (line 91).
1/// A dry-run frame graph compared with the frame that followed it.
2library;

4import 'package:flutter3d/flutter3d.dart';
5import 'package:flutter3d_showcase/src/demo/demo.dart';
6import 'package:vector_math/vector_math.dart';

8final class FrameGraphDemo extends ShowcaseDemo {
bool bloom = true;
bool antiAlias = true;

late final Scene _scene;
List<String> _planned = const <String>[];
List<String> _skipped = const <String>[];

@override
void configureView(DemoContext context) {
  context.orbit
    ..distance = 6.5
    ..pitch = 0.25
    ..yaw = 0.45;
}

@override
Scene build(DemoContext context) {
  final Material bright = Material(
    name: 'bright metal',
    baseColor: Vector4(0.7, 0.2, 0.08, 1.0),
    emissive: Vector3(1.0, 0.16, 0.03),
    emissiveStrength: 2.5,
    metallic: 0.62,
    roughness: 0.22,
  );
  _scene = Scene()
    ..ambientColor = Vector3(0.38, 0.46, 0.64)
    ..ambientIntensity = 0.12
    ..add(
      MeshNode(
        DeviceMesh.upload(
          context.device,
          const TorusShape(radius: 1.15, tubeRadius: 0.38).build(),
        ),
        bright,
        name: 'emissive torus',
      ),
    )
    ..add(
      LightNode(name: 'sun', intensity: 3.0)
        ..setLocalForward(Vector3(-0.45, -0.82, -0.35)),
    );
  return _scene;
}

@override
RenderSettings settings(DemoContext context) {
  final RenderSettings next = RenderSettings(
    bloom: BloomSettings(intensity: bloom ? 0.65 : 0.0),
    antiAlias: AntiAliasSettings(enabled: antiAlias),
  );

  final CompiledFrameGraph graph = context.renderer.planFrame(
    scene: _scene,
    views: <RenderView>[context.view],
    settings: next,
  );
  _planned = <String>[
    for (final FrameGraphNode node in graph.order) node.name,
  ];
  _skipped = <String>[
    for (final SkippedPass pass in graph.skipped) pass.name,
  ];
  return next;
}

@override
List<DemoControl> controls(DemoContext context) => <DemoControl>[
  ToggleControl(
    'Bloom pass',
    value: () => bloom,
    onChanged: (bool value) => bloom = value,
  ),
  ToggleControl(
    'Antialias pass',
    value: () => antiAlias,
    onChanged: (bool value) => antiAlias = value,
  ),
];

@override
void verify(Scene scene, FrameResult frame) {
  final List<String> drawn = <String>[
    for (final FramePass pass in frame.passes) pass.name,
  ];
  if (_planned.isEmpty ||
      !_planned.contains('scene') ||
      !_planned.contains('composite') ||
      bloom && !_planned.contains('bloom') ||
      antiAlias && !_planned.contains('antialias') ||
      !_sameNames(_planned, drawn) ||
      _skipped.any(drawn.contains)) {
    throw StateError('the planned graph did not match the drawn frame');
  }
}
104}

106bool _sameNames(List<String> left, List<String> right) {
if (left.length != right.length) return false;
for (var i = 0; i < left.length; i++) {
  if (left[i] != right[i]) return false;
}
return true;
112}