Struct ViewportRuntime 

pub struct ViewportRuntime { /* private fields */ }

Per-frame scene orchestration layer.

Owns plugins, an optional fixed timestep accumulator, and a transform snapshot table. Does not own the scene, selection, GPU resources, or window.

Priority execution order

Each call to step executes plugins in ascending priority order:

1. [i32::MIN, SELECT) – Prepare (100), Pick (200): once, at wall dt
2. [SELECT, MANIPULATE) – Select (300): once (built-in SelectionSystem runs first)
3. [MANIPULATE, SIMULATE) – Manipulate (400), Animate (500): once
4. [SIMULATE, POST_SIM) – Simulate (600): once per fixed step or once at wall dt
5. [POST_SIM, i32::MAX] – PostSim (700), Writeback (800): once at wall dt

Implementations

impl ViewportRuntime

pub fn new() -> Self

Create a runtime with default settings and no plugins.

pub fn with_selection_system(self) -> Self

Enable the built-in click-to-select system.

The SelectionSystem runs before the Select phase each frame. It reads RuntimeFrameContext::clicked, pick_hit, and shift_held to produce SelectionOp entries in RuntimeOutput.

pub fn with_manipulation_system(self) -> Self

Enable the built-in manipulation system.

The ManipulationSystem runs before the Manipulate phase each frame. It drives G/R/S sessions and gizmo drag from RuntimeFrameContext inputs, writing transform changes via TransformWriteback.

pub fn is_manipulating(&self) -> bool

True while the built-in manipulation system has an active G/R/S session or gizmo drag.

Use this to suppress orbit camera movement while manipulating objects.

pub fn manipulation_system(&self) -> Option<&ManipulationSystem>

Access the built-in manipulation system, if enabled.

pub fn with_mode(self, mode: SceneRuntimeMode) -> Self

Set the runtime mode.

pub fn with_plugin(self, plugin: impl RuntimePlugin) -> Self

Register a plugin. Plugins run in ascending priority order each frame. Plugins with equal priority run in registration order (stable sort).

pub fn with_fixed_timestep(self, ts: FixedTimestep) -> Self

Enable fixed-timestep accumulation for physics plugins.

When set, plugins in the [SIMULATE, POST_SIM) range run once per accumulated fixed step rather than once per frame at wall dt. All other priority ranges always run once per frame.

pub fn set_fixed_timestep(&mut self, ts: FixedTimestep)

Replace the fixed timestep at runtime. Resets the accumulator.

Use this to change the simulation rate after construction without rebuilding the runtime or its plugins.

pub fn clear_fixed_timestep(&mut self)

Remove the fixed timestep, reverting to one simulate call per frame at wall dt.

pub fn mode(&self) -> SceneRuntimeMode

The current runtime mode.

pub fn snapshots(&self) -> &TransformSnapshotTable

The transform snapshot table for interpolated rendering.

Updated each frame during writeback. Pass alpha as the blend factor to TransformSnapshotTable::interpolated.

pub fn resources(&self) -> &RuntimeResources

Read access to the shared resource registry.

Use this after step to inspect resources without running the frame loop. During the frame loop, access resources through RuntimeStepContext::resources.

pub fn resources_mut(&mut self) -> &mut RuntimeResources

Write access to the shared resource registry.

Use this to pre-populate resources before the first step, or to inject resources from outside the plugin system (e.g. from the application).

pub fn alpha(&self) -> f32

Blend factor for rendering interpolation between fixed steps.

Returns 1.0 if no fixed timestep is configured (render directly from current scene transforms without interpolation).

pub fn step_index(&self) -> u64

Monotonically increasing simulation step counter.

Incremented once per simulate execution. With a fixed timestep this means it may increment multiple times per rendered frame. Wraps on overflow.

pub fn with_camera_follow(self, follow: CameraFollow) -> Self

Set a camera follow binding (builder style).

Each call to step will compute a suggested camera center from the followed node and return it in RuntimeOutput::camera_follow_target.

pub fn set_camera_follow(&mut self, follow: CameraFollow)

Update the camera follow binding at runtime.

pub fn clear_camera_follow(&mut self)

Remove the camera follow binding. RuntimeOutput::camera_follow_target will be None after this call.

pub fn camera_follow(&self) -> Option<&CameraFollow>

The current camera follow binding.

pub fn step( &mut self, scene: &mut Scene, selection: &mut Selection, frame: &RuntimeFrameContext, ) -> RuntimeOutput

Run one frame of the runtime.

Plugins run in ascending priority order. The simulate range [SIMULATE, POST_SIM) runs once per accumulated fixed step (or once at frame.dt when no fixed timestep is configured). All other ranges run once per frame. Transform ops are flushed to scene and the snapshot table is updated after the writeback range.

Selection ops produced by plugins are applied to selection before returning. Contact events and the applied transform ops are returned in RuntimeOutput.

Trait Implementations

impl Default for ViewportRuntime

fn default() -> Self

Returns the “default value” for a type.