What a frame reports: the source

since 0.7.0 Scene and geometry
Open the live demo · Read the guide · View on GitHub
Regions the guide quotes: geometry (line 24), light (line 69), totals (line 91), check (line 102).
1/// A small mixed scene whose result exposes useful frame counters.
2library;

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

8final class FrameStatsDemo extends ShowcaseDemo {
bool shadows = true;

late final LightNode _sun;

@override
void configureView(DemoContext context) {
  context.orbit
    ..distance = 8.0
    ..pitch = 0.3
    ..yaw = 0.5;
  context.orbit.target.setValues(0.0, 0.7, 0.0);
}

@override
Scene build(DemoContext context) {
  final Material matte = Material(
    name: 'matte',
    baseColor: Vector4(0.24, 0.62, 0.82, 1.0),
    roughness: 0.72,
  );
  final Material metal = Material(
    name: 'metal',
    baseColor: Vector4(0.82, 0.43, 0.18, 1.0),
    metallic: 0.76,
    roughness: 0.24,
  );
  final Scene scene = Scene()
    ..ambientColor = Vector3(0.42, 0.5, 0.68)
    ..ambientIntensity = 0.12
    ..add(
      MeshNode(
        DeviceMesh.upload(
          context.device,
          const PlaneShape(width: 8.0, depth: 7.0).build(),
        ),
        matte.copy()..doubleSided = true,
        name: 'floor',
      )..castsShadow = false,
    )
    ..add(
      MeshNode(
        DeviceMesh.upload(
          context.device,
          CuboidShape(size: Vector3.all(1.5)).build(),
        ),
        matte,
        name: 'cube',
      )..setPosition(-1.25, 0.75, 0.0),
    )
    ..add(
      MeshNode(
        DeviceMesh.upload(
          context.device,
          const TorusShape(radius: 0.72, tubeRadius: 0.28).build(),
        ),
        metal,
        name: 'torus',
      )..setPosition(1.35, 1.0, 0.0),
    );

  _sun = LightNode(name: 'sun', intensity: 3.2, castsShadow: shadows)
    ..setLocalForward(Vector3(-0.45, -0.82, -0.35));
  scene.add(_sun);
  return scene;
}

@override
void update(DemoContext context, double dt) {
  _sun.castsShadow = shadows;
}

@override
List<DemoControl> controls(DemoContext context) => <DemoControl>[
  ToggleControl(
    'Shadow pass',
    value: () => shadows,
    onChanged: (bool value) => shadows = value,
  ),
];

@override
void verify(Scene scene, FrameResult frame) {
  final FramePass scenePass = frame.passes.firstWhere(
    (FramePass pass) => pass.name == 'scene',
  );
  final FramePass compositePass = frame.passes.firstWhere(
    (FramePass pass) => pass.name == 'composite',
  );
  final int passDraws = frame.passes.fold<int>(
    0,
    (int total, FramePass pass) => total + pass.drawCalls,
  );

  if (scenePass.drawCalls < 3 ||
      compositePass.drawCalls != 1 ||
      frame.drawCalls != passDraws ||
      frame.triangles <= 0 ||
      frame.pipelineSwitches <= 0 ||
      frame.cpuMicros < frame.submitMicros) {
    throw StateError('the frame counters do not describe the rendered scene');
  }
}
111}