# API overview
`scena` exposes a small set of public types that cover the normal 3D
application workflow: create assets, build a scene, prepare renderer resources,
and render frames.
The authoritative API reference is generated on docs.rs:
<https://docs.rs/scena/latest/scena/>
Use this page as the conceptual map.
Additive public API changes in 1.7.0:
- `Transform`, `Aabb`, `Color`, `GeometryTopology`, capability enums, and
capability report structs now serialize through stable serde shapes.
- `CAPABILITY_REPORT_SCHEMA_V1`
- `CapabilityReportV1`
- `CapabilityReport::to_schema_report`
- `CapabilityReport::to_schema_json`
- `SCENE_INSPECTION_SCHEMA_V1` (gated behind `inspection`)
- `SceneInspectionReportV1`, `SceneNodeInspectionV1`,
`SceneDrawInspectionV1`, `SceneCameraFrustumInspectionV1`,
`SceneNormalInspectionV1`, `SceneInspectionCountsV1`, and
`SceneInspectionRevisionsV1` (gated behind `inspection`)
- `SceneInspectionReport::to_schema_report`
- `SceneInspectionReport::to_schema_report_with_node_handles`
- `SceneInspectionReport::to_schema_json`
- `SceneInspectionReportV1::node_by_handle`
- `SceneInspectionReportV1::children_of`
- `SceneInspectionReportV1::roots`
- `SceneInspectionReportV1::find_by_tag`
- `Transform::compose`
- `impl Mul<Transform> for Transform`
- `Assets::load_scene_from_bytes`
- `Scene::instantiate_under`
- `Scene::set_transforms`
- `Scene::set_node_tint`
- `Scene::node_tint`
- `Scene::set_annotation_anchor`
- `Scene::clear_annotation_anchor`
- `Scene::annotation_projection_report`
- `Scene::world_distance`
- `Scene::node_world_bounds`
- `Node::tint`
- `Scene::remove_node`
- `Scene::remove_import`
- `Scene::remove_tag`
- `SceneAsset::primitive_count`
- `SceneAsset::bounds`
- `SceneAsset::geometry_summary`
- `ASSET_LOAD_REPORT_SCHEMA_V1`
- `AssetLoadReportV1`, `AssetLoadWarningV1`, and `AssetLoadProgressV1`
- `AssetLoadReport<SceneAsset>::to_schema_report`
- `AssetLoadReport<SceneAsset>::to_schema_json`
- `AssetLoadOptions::with_strict_external_resources`
- `AssetProvenance` and `AssetDerivative`
- `SceneAsset::provenance`
- `TextureDesc::provenance`
- `EnvironmentDesc::provenance`
- `AnnotationAnchor`, `AnnotationAnchorTarget`,
`AnnotationProjectionReportV1`, `AnnotationProjectionV1`,
`SCENE_ANNOTATION_PROJECTION_SCHEMA_V1`,
`SceneAssetGeometrySummary`, and
`ASSET_GEOMETRY_SUMMARY_SCHEMA_V1`
- `SceneHostCore` (gated behind `scene-host`)
- `SceneHostError` and `SceneHostErrorCode` (gated behind `scene-host`)
- `SceneHostCameraState` (gated behind `scene-host`)
- `SCENE_HOST_ASSET_IMPORT_SCHEMA_V1` and
`SceneHostAssetImportReportV1` (gated behind `scene-host`)
- `SCENE_HOST_SUBTREE_SCHEMA_V1`, `SceneHostSubtreeReportV1`, and
`SceneHostSubtreeNodeV1` (gated behind `scene-host`)
- `SCENE_HOST_ANIMATION_INVENTORY_SCHEMA_V1`,
`SceneHostAnimationInventoryV1`, `SceneHostAnimationClipV1`,
`SceneHostAnimationPlayOptions`, `SceneHostAnimationLoopMode`, and
`SceneHostEasing` (gated behind `scene-host`)
- `RendererStats::gpu_draw_submissions` and `RendererStats::instances`
- `AntiAliasing`, `PostBloomConfig`,
`ScreenSpaceAmbientOcclusionConfig`, `Renderer::set_anti_aliasing`,
`Renderer::set_bloom`, and `Renderer::set_screen_space_ambient_occlusion`
- `CAPTURE_SCHEMA_V1`
- `capture_rgba8`
- `Renderer::capture_rgba8`
- `FirstRender::capture`
- `HeadlessGltfViewer::capture`
- `InteractiveGltfViewer::capture`
- `CaptureDescriptor`, `CaptureRgba8`, `CaptureOptions`,
`CaptureRevisions`, `CaptureCamera`, `CaptureProjection`,
`CaptureViewport`, `CapturePayload`, `CapturePayloadKind`,
`CaptureAutoFrame`, `CaptureAutoFrameViewport`, `CapturePoint2`,
`CaptureScreenRect`, `CapturePixelSummary`, `CapturePixelBounds`, and
`CaptureError`
- `fnv1a64_hex`, `sample_rgba8`, `summarize_rgba8`,
`summarize_pixel_readback`, and `auto_frame_metadata`
The `scene-host` feature also exports a WASM `SceneHost` wrapper on
`wasm32`. Its node handles are opaque `u64` values owned by the host. The same
handle values are used for construction, transform updates, picking, and
`inspectJson()` output. Phase 3 also exports real `capture()` /
`captureJson()` methods that return `scena.capture.v1` metadata for the latest
rendered RGBA8 frame; these are not placeholders. Capture descriptors are
bound to the renderer's last rendered scene/camera state and fail with
`CaptureError::StaleRender` if the scene is mutated before capture.
Phase 4 adds real `removeNode` and `removeImport` host methods. Removed node
handles are invalidated in the host table, so later use returns
`SceneHostErrorCode::StaleNodeHandle` rather than aliasing a recycled node.
Phase 4 also adds per-node tint/highlight render state. Native callers use
`Scene::set_node_tint(node, Some(color))` or `None` to clear it; browser hosts
use `setNodeTint` and `clearNodeTint`. Tint is node-owned render state, not a
material clone, and `scena.scene_inspection.v1` reports it as
`nodes[].tint`.
Phase 4 also adds engine-owned annotation projection and geometry helpers.
Native callers can store `AnnotationAnchor::node` / `AnnotationAnchor::world`
anchors and call `Scene::annotation_projection_report` for schema
`scena.annotation_projection.v1`. Browser hosts use `setNodeAnnotation`,
`setWorldAnnotation`, `clearAnnotation`, and `annotationProjectionsJson()`,
which returns CSS-pixel projection coordinates and the same host `node_handle`
for node anchors that `setTransforms`, `inspectJson`, and `pick` use. World
anchors report `node_handle: null`. `SceneAsset::geometry_summary` returns
schema `scena.asset_geometry_summary.v1` with node/mesh/primitive counts,
asset-local bounds, and source metadata where the asset stores it.
Phase 5 adds stable asset-load reports. Native callers use
`AssetLoadReport<SceneAsset>::to_schema_json()` for
`scena.asset_load_report.v1`; browser hosts can call
`instantiateUrlWithReportJson` or `instantiateUrlUnderWithReportJson` to get
the created import handle plus the same asset-load report. Cache-hit reports
preserve typed warnings and external resource counts from the original load.
Release 1.7 adds explicit host-owned instanced imports. Native callers use
`SceneHostCore::instantiate_url_instanced` or
`SceneHostCore::instantiate_url_instanced_under`; browser hosts use
`instantiateUrlInstanced` or `instantiateUrlInstancedUnder`. Each returned
handle is an instance-root handle, not a scene node. The standard transform,
visibility, tint, remove, and pick APIs accept these handles. Other node-tree
APIs continue to reject them with structured host errors. Per-instance tint is
opaque-only in this release.
Release 1.7 also adds post-processing controls, world-space stroke rendering,
SceneHost animation playback, and presentation transitions. Browser and native
hosts explicitly call `advance(delta_seconds)` once per frame to step active
animation mixers and transition fades; `SceneHost` does not own the host
application's render loop. Eased transforms and tints are renderer presentation
smoothing for low-rate visual updates, not simulation, physics, robotics, or
process-control behavior.
Release 1.7 subtree reports use schema `scena.subtree.v1`; node `name` is
reserved for future stable naming policy and is always `null` in 1.7. Use
stable host handles and sorted `tags` for identification.
The stable contract surface also includes generic `AssetProvenance` metadata.
Loaded `SceneAsset`,
`TextureDesc`, and `EnvironmentDesc` values expose `provenance()` with a
serde-stable source path, optional source SHA-256, optional license/generator,
and generated derivatives. `scena.asset_load_report.v1` and
`scena.asset_geometry_summary.v1` include the same provenance value. Existing
environment source accessors continue to delegate to the same provenance
record.
SceneHost includes interactive camera state without giving the host a render
loop. Native code can call `SceneHostCore::set_camera`,
`SceneHostCore::get_camera`, `SceneHostCore::camera_json`,
`camera_pointer_down`, `camera_pointer_move`, `camera_pointer_up`, and
`camera_wheel`. The WASM facade exposes the corresponding `setCamera`,
`setCameraJson`, `getCameraJson`, `cameraPointerDown`, `cameraPointerMove`,
`cameraPointerUp`, and `cameraWheel` methods.
Runnable SceneHost examples:
```bash
cargo run --example scene_host_contracts --features scene-host
cargo run --example scene_host_release_1_7 --features scene-host
```
`examples/scene_host_release_1_7.rs` is the compact native 1.7 surface sample:
post-processing setters, instanced import, visibility/tint, camera preset
framing, animation inventory/play/pause/advance, and eased transform/tint
updates. `examples/scene_host_browser_contracts.js` shows the matching WASM
method names: `setAntiAliasing`, `setBloom`, `setAmbientOcclusion`,
`instantiateUrlInstancedUnder`, `setVisible`, `setNodeTint`,
`animationInventoryJson`, `playAnimation`, `pauseAnimation`, `advance`,
`setTransformEased`, `setTransformsEasedTyped`, and `setNodeTintEased`.
Golden JSON fixtures for the shipped v1 reports live under
`tests/assets/stable-contracts/`.
Additive public API changes in 1.2.0:
- `AssetLoadOptions`
- `Assets::load_scene_with_options`
- `Assets::load_scene_with_report_options`
- `DiagnosticCode::MaterialTextureMissingDecodedPixels`
- `RendererStats::material_textures_missing_decoded_pixels`
Additive public API changes in 1.3.0:
- `Scene::frame_bounds`
- `FramingOptions`
- `FramingOptions::azimuth_elevation`
- `FramingOptions::front`
- `FramingOptions::back`
- `FramingOptions::left`
- `FramingOptions::right`
- `FramingOptions::top`
- `FramingOptions::bottom`
- `FramingOptions::three_quarter_front_left`
- `FramingOptions::three_quarter_front_right`
- `FramingOptions::three_quarter_back_left`
- `FramingOptions::three_quarter_back_right`
- `FramingOutcome`
- `ScreenRect`
- `ProjectedPoint`
- `Scene::project_world_point`
- `Scene::bounds_for_transforms`
- `Scene::add_grid_floor`
- `GridFloorOptions`
- `GridFloorHandles`
- `Aabb::union`
- `OrbitControls::focus_on_framing`
- `OrbitControls::from_framing`
- `Scene::add_studio_lighting`
- `Renderer::set_auto_exposure`
- `AutoExposureConfig`
- `AutoExposureResult`
Additive public API changes in 1.4.0:
Named primitives — "write a name, not a number":
- `Color::TRANSPARENT`, `Color::BLACK`, `Color::WHITE`, `Color::GRAY`,
`Color::LIGHT_GRAY`, `Color::DARK_GRAY`, `Color::CHARCOAL`,
`Color::STUDIO_BACKDROP`, `Color::WARM_WHITE`, `Color::COOL_WHITE`,
`Color::RED`, `Color::GREEN`, `Color::BLUE`, `Color::ORANGE`,
`Color::YELLOW`, `Color::CYAN`, `Color::MAGENTA`
- `Color::from_hex`
- `Color::from_kelvin`
- `PerspectiveCamera::wide_angle`
- `PerspectiveCamera::standard`
- `PerspectiveCamera::portrait`
- `PerspectiveCamera::telephoto`
- `PerspectiveCamera::with_fov_degrees`
- `Transform::looking_at`
- `DirectionalLight::sun`
- `DirectionalLight::key_light`
- `DirectionalLight::fill_light`
- `DirectionalLight::rim_light`
- `PointLight::softbox`
- `PointLight::bulb_warm`
- `PointLight::bulb_cool`
- `MaterialDesc::matte`
- `MaterialDesc::plastic`
- `MaterialDesc::metal`
- `MaterialDesc::rubber`
- `Background` (enum: `Studio`, `DarkStudio`, `NeutralGray`, `White`,
`Black`, `Sky`, `Transparent`, `Custom(Color)`)
- `Renderer::set_background`
- `OrbitControls::cinematic`
- `OrbitControls::snappy`
- `OrbitControls::presentation`
- `OrbitControls::turntable`
- `OrbitControls::zoom_limits_bounds_relative`
- `OrbitControls::with_distance_limits`
- `AutoExposureConfig::product_studio`
- `AutoExposureConfig::indoor`
- `AutoExposureConfig::outdoor`
- `AutoExposureConfig::mixed`
Bundled content + one-call helpers:
- `EnvironmentPreset`, `EnvironmentPresetMetadata`,
`Assets::load_environment_preset`
- `KhronosSample`, `KhronosSamples`, `KhronosSampleMetadata`,
`Assets::khronos`
- `Scene::play_animation_by_name`
- `HeadlessGltfViewer::play_clip`,
`InteractiveGltfViewer::play_clip`
- `Scene::add_perspective_camera_default_for`
- `ConnectOptions::with_axial_gap`
- `Scene::preview_connector_magnet`, `ConnectionMagnetPreview`,
`ConnectionMagnetVisualCue`
Viewer ergonomics — pointer callbacks, screenshots, hot reload, URL state:
- `InteractiveGltfViewer::on_click`,
`InteractiveGltfViewer::on_hover`,
`InteractiveGltfViewer::clear_click_callback`,
`InteractiveGltfViewer::clear_hover_callback`,
`InteractiveGltfViewer::click_at`,
`InteractiveGltfViewer::hover_at`,
`InteractiveGltfViewer::pick_at`,
`InteractiveGltfViewer::pick_and_select_at`,
`InteractiveGltfViewer::pick_and_hover_at`
- `HeadlessGltfViewer::capture_png_bytes`,
`HeadlessGltfViewer::capture_png`,
`InteractiveGltfViewer::capture_png_bytes`,
`InteractiveGltfViewer::capture_png`,
`FirstRender::capture_png_bytes`,
`FirstRender::capture_png`,
`HeadlessGltfViewerBuilder::render_png_bytes`,
`HeadlessGltfViewerBuilder::render_png`,
`ViewerCaptureError`, `ViewerPngError`
- `Assets::watch_scene_for_hot_reload`,
`Assets::reload_scene`,
`AssetHotReloadWatcher`, `AssetHotReloadError`
(gated behind the `hot-reload` feature)
- `CameraOrbitUrlState`
- `FollowControls`, `FlyControls`
- `ReferenceImage::from_rgba8`, `ReferenceImage::regress`,
`ReferenceImage::regress_with_tolerance`
`<scena-viewer>` custom element (browser):
- `defineScenaViewer()`
- `ScenaViewerDropDecision`, `ScenaViewerVariantSelection`,
`ScenaViewerInspectorSnapshot`, `ScenaViewerProgress`,
`ScenaViewerProgressPhase`, `ScenaViewerAccessibilityDefaults`,
`ScenaViewerKeyboardAction`, `ScenaViewerGestureAction`,
`ScenaViewerAnnotationAnchor`
Renderer features:
- `Renderer::set_bloom`
- `Renderer::clear_bloom`
- `PostBloomConfig`
- `Renderer::set_anti_aliasing`
- `AntiAliasing`
- `Renderer::set_screen_space_ambient_occlusion`
- `Renderer::clear_screen_space_ambient_occlusion`
- `ScreenSpaceAmbientOcclusionConfig`
- `Renderer::set_order_independent_transparency`
- `Renderer::clear_order_independent_transparency`
- `OrderIndependentTransparencyConfig`
- `MaterialDesc::with_clearcoat_factor`,
`MaterialDesc::with_clearcoat_roughness_factor`,
`MaterialDesc::with_clearcoat_texture`,
`MaterialDesc::with_clearcoat_roughness_texture`,
`MaterialDesc::with_clearcoat_normal_texture`,
`MaterialDesc::clearcoat_factor`,
`MaterialDesc::clearcoat_roughness_factor`,
`MaterialDesc::clearcoat_texture`,
`MaterialDesc::clearcoat_roughness_texture`,
`MaterialDesc::clearcoat_normal_texture`,
`MaterialDesc::clearcoat_normal_scale`
- `MaterialDesc` sheen / anisotropy / iridescence / dispersion /
transmission / IOR / volume builders and accessors
- `OutputColorSpace`,
`RendererOptions::with_output_color_space`,
`Capabilities::wide_gamut_output`,
`DiagnosticCode::WideGamutOutputUnavailable`
- `GltfExtensionDiagnostic::suggested_fix`
- `RendererStats::ambient_occlusion_passes`
- `RendererStats::order_independent_transparency_passes`
- `RendererStats::bloom_passes`
Additive public API changes in 1.5.0:
- `MaterialDesc::rough_metal`
- `MaterialDesc::chrome`
- `MaterialDesc::brushed_steel`
- `MaterialDesc::clearcoat_plastic`
- `MaterialDesc::satin`
- `MaterialDesc::leather`
- `MaterialDesc::clear_glass`
- `MaterialDesc::frosted_glass`
## Core types
| `Scene` | Owns graph state: nodes, transforms, cameras, lights, renderables, labels, imports, animations, picking targets, and dirty state. |
| `Assets` | Owns logical resources: geometry, materials, textures, environments, parsed glTF/GLB assets, cache identity, reload, and retain policy. |
| `Renderer` | Owns rendering state: backend resources, prepared scene data, surfaces, targets, stats, diagnostics, capability reports, and frame output. |
| `SceneImport` | Represents an instantiated imported asset with roots, names, paths, anchors, connectors, bounds, clips, and stale-import checks. |
The common pattern is:
```rust
let mut assets = scena::Assets::new();
let asset = assets.load_scene("model.glb")?;
let mut scene = scena::Scene::new();
let import = scene.instantiate(&asset)?;
let bounds = import.bounds_world(&scene).ok_or("model has no bounds")?;
scene.add_studio_lighting()?;
scene.add_grid_floor(&assets, scena::GridFloorOptions::new().under_bounds(bounds))?;
let camera = scene.add_perspective_camera(
scene.root(),
scena::PerspectiveCamera::standard(),
scena::Transform::default(),
)?;
let framing = scene.frame_bounds(
camera,
bounds,
scena::FramingOptions::new()
.three_quarter_front_right()
.fill(0.72)
.viewport(1280, 720),
)?;
let controls = scena::OrbitControls::from_framing(framing);
let mut renderer = scena::Renderer::headless(1280, 720)?;
renderer.set_auto_exposure(scena::AutoExposureConfig::default());
renderer.prepare_with_assets(&mut scene, &assets)?;
renderer.render(&scene, camera)?;
```
See the exact signatures on docs.rs and the runnable examples in `examples/`.
## Typed handles
`scena` uses typed handles instead of raw integers or string identifiers for
renderer-owned objects.
Examples include:
- `NodeKey`
- `CameraKey`
- `GeometryHandle`
- `MaterialHandle`
- `TextureHandle`
- `EnvironmentHandle`
- `AnimationMixerKey`
- `InstanceSetKey`
- `HitTarget`
Typed handles make wrong-kind usage visible at compile time. Missing or stale
handles return structured errors.
## Scene construction
`Scene` is the place for graph state:
- node hierarchy,
- transforms,
- cameras,
- lights,
- renderable instances,
- labels and helper geometry,
- imported asset instances,
- animation mixers,
- picking state,
- visibility and layers.
Scene builders return typed keys or handles. Hosts keep application-specific
state in their own model and map the visible portion into `Scene`.
Common animation calls:
- `Scene::play_animation_by_name`
- `Scene::update_animation`
- `Scene::set_animation_loop_mode`
- `Scene::set_animation_speed`
Viewer helpers also expose `play_clip(name)` for the loaded import. The
returned mixer key is still scene-owned, so hosts explicitly drive update,
loop, speed, prepare, and render.
## Asset ownership
`Assets` owns resource creation and loading:
- primitive geometry,
- materials,
- textures,
- environments,
- glTF/GLB scene assets,
- cache and reload state,
- external asset fetching.
The renderer does not fetch or parse assets during `render()`. Load and decode
assets before preparation.
## Renderer lifecycle
`Renderer` has an explicit lifecycle:
1. Build or mutate `Scene` and `Assets`.
2. Call `prepare()` or `prepare_with_assets()`.
3. Call `render()` or `render_active()`.
4. If scene, assets, surface, target, environment, or renderer settings change,
call `prepare()` again.
This keeps fallible work visible to the host and makes frame rendering
predictable.
Common renderer calls:
- `Renderer::headless`
- `Renderer::headless_gpu`
- `Renderer::from_surface`
- `Renderer::prepare`
- `Renderer::prepare_with_assets`
- `Renderer::render`
- `Renderer::render_active`
- `Renderer::set_debug`
- `Renderer::set_debug_overlay`
- `Renderer::capability_report`
- `Renderer::gpu_adapter_report`
Common scene interaction calls:
- `Scene::pick_with_assets`
- `Scene::pick_and_select_with_assets`
- `Scene::connect_import_connectors`
- `Scene::frame_bounds`
- `Scene::project_world_point`
- `Scene::bounds_for_transforms`
- `Scene::add_grid_floor`
- `Scene::add_studio_lighting`
- `Scene::with_default_camera()`
Common public event and output types:
- `SurfaceEvent`
- `DebugOverlay`
- `PostBloomConfig`
- `RendererStats`
- `CapabilityReport`
- `GpuAdapterReport`
- `AdapterLimitsReport`
- `AssetEvictionStats`
- `AssetStoreId`
- `ReferenceImage`
- `ReferenceImageReport`
- `ReferenceImageTolerance`
Common asset-store calls:
- `Assets::store_id()`
- `Assets::load_scene_with_options()`
- `Assets::load_scene_with_report_options()`
- `Assets::contains_geometry`
- `Assets::contains_material`
- `Assets::contains_texture`
- `Assets::contains_environment`
- `Assets::release_unreferenced`
Common import and connector contracts:
- `SceneImport`
- `AnchorKey`
- `ConnectorKey`
- `AnchorFrame`
- `ConnectorFrame`
- `ConnectorMetadata`
- `ConnectionAlignment`
- `ConnectionRoll`
- `ConnectionLineOverlay`
- `ConnectionMagnetPreview`
- `ConnectionMagnetVisualCue`
- `ConnectorRollPolicy`
- `ConnectorPolarity`
Common viewer helpers:
- `FramingOptions`
- `FramingOutcome`
- `GridFloorOptions`
- `GridFloorHandles`
- `InteractiveGltfViewer`
- `InteractiveGltfViewerBuilder`
- `interactive_gltf_viewer(path, surface)`
- `InteractiveGltfViewer::handle_surface_event`
- `HeadlessGltfViewerBuilder::build_with_progress`
- `HeadlessGltfViewerBuilder::render_png_bytes`
- `InteractiveGltfViewerBuilder::build_with_progress`
- `AssetLoadProgress`
- `HeadlessGltfViewer::set_active_material_variant`
- `InteractiveGltfViewer::set_active_material_variant`
- `Renderer::headless_default()`
- `Renderer::set_auto_exposure`
Common visual-regression helpers:
- `ReferenceImage::from_rgba8`
- `regress`
- `regress_with_tolerance`
## Errors and diagnostics
Public failures use structured errors such as:
- `BuildError`
- `AssetError`
- `ImportError`
- `InstantiateError`
- `LookupError`
- `PrepareError`
- `RenderError`
- `AnimationError`
- `ConnectionError`
- `ColorParseError`
- `ReferenceImageError`
- `ViewerCaptureError`
- `ViewerPngError`
Most errors include a stable category plus contextual data. Use pattern matching
for application behavior and `.help()` or diagnostics output for user-facing
messages.
glTF extension diagnostics from `SceneAsset::extension_diagnostics()` also
include `suggested_fix()` and `decoder_policy()` so importer and asset-review
UIs can show the same actionable remediation used by the asset doctor.
## Stats and capabilities
`Renderer` exposes runtime information for:
- backend capability reports,
- GPU adapter reports,
- renderer statistics,
- debug overlays,
- resource and frame counters.
Use capability reports when selecting optional effects or platform-specific
paths. Use stats for testing, diagnostics, and performance visibility.
`RendererStats::draw_calls` and `RendererStats::primitives` are deprecated
aliases of `RendererStats::triangles` and retain their historical triangle-count
meaning until the next schema version. Use `RendererStats::gpu_draw_submissions`
for the actual number of GPU draw/draw-indexed/draw-instanced calls submitted
last frame, and `RendererStats::instances` for the number of visible per-instance
records drawn last frame.
`Capabilities::wide_gamut_output` is intentionally capability-gated: headless
and unattached reports stay disabled, attached browser reports stay degraded
until the browser smoke probe records Display P3 canvas support for the active
backend.
## Where to go next
- [Getting started](getting-started.md)
- [Rendering](rendering.md)
- [Assets](assets.md)
- [Lifecycle](lifecycle.md)
- [Errors](errors.md)
- [Capabilities](capabilities.md)