Module `root_motion`

Root-motion extraction and composition utilities.

Quick Reference

Item	Kind	Description
`RootMotionDelta`	struct	The `RootMotionDelta` struct carries one frame's local translation and rotation change to gameplay.
`RootMotionError`	enum	Errors returned when root motion cannot be extracted from a pose pair.
`extract_root_motion`	fn	Extracts one root node's motion and resets its translation and rotation to a reference pose.
`forward_loop_root_motion`	fn	Calculates a forward loop-wrap delta by joining the end and start segments.

Structs

`RootMotionDelta`

struct RootMotionDelta {
    pub translation: [f32; 3],
    pub rotation: [f32; 4],
}

Defined in crates/byte-engine/src/animation/root_motion.rs:9-14

The RootMotionDelta struct carries one frame's local translation and rotation change to gameplay.

Fields

translation: [f32; 3]

Translation to apply in the skeleton root's parent space.
rotation: [f32; 4]

Rotation to apply after the previous root rotation.

Implementations

```
const IDENTITY: Self
```
```
fn between(previous: LocalTransform, current: LocalTransform) -> Self
```
Calculates the shortest local transform delta between two sampled root poses.
```
fn then(self, next: Self) -> Self
```
Composes this delta followed by next.

Translation remains in the skeleton root's parent space, so segment

translations add directly. Use this to join root-motion segments across

a looping clip boundary.

fn blend(self, other: Self, factor: f32) -> Self

Blends two root-motion deltas for pose blending.

Trait Implementations

`impl ArchivePointee for RootMotionDelta`

```
type ArchivedMetadata = ()
```

fn pointer_metadata(_: &<T as ArchivePointee>::ArchivedMetadata) -> <T as Pointee>::Metadata

`impl<ST> CastableFrom for RootMotionDelta`

`impl Clone for RootMotionDelta`

```
fn clone(&self) -> RootMotionDelta
```
Related: RootMotionDelta

`impl Copy for RootMotionDelta`

`impl Debug for RootMotionDelta`

fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result

`impl Default for RootMotionDelta`

```
fn default() -> Self
```

`impl Downcast for RootMotionDelta`

fn into_any(self: Box<T>) -> Box<dyn Any>

fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>

```
fn as_any(&self) -> &dyn Any
```

fn as_any_mut(&mut self) -> &mut dyn Any

`impl DowncastSend for RootMotionDelta`

fn into_any_send(self: Box<T>) -> Box<dyn Any + Send>

`impl DowncastSync for RootMotionDelta`

fn into_any_arc(self: Arc<T>) -> Arc<dyn Any + Sync + Send>

`impl Instrument for RootMotionDelta`

`impl LayoutRaw for RootMotionDelta`

fn layout_raw(_: <T as Pointee>::Metadata) -> Result<Layout, LayoutError>

`impl<T, N1> Niching for RootMotionDelta`

unsafe fn is_niched(niched: *const NichedOption<T, N1>) -> bool

fn resolve_niched(out: Place<NichedOption<T, N1>>)

`impl PartialEq for RootMotionDelta`

fn eq(&self, other: &RootMotionDelta) -> bool

Related: RootMotionDelta

`impl Pointable for RootMotionDelta`

```
const ALIGN: usize
```
```
type Init = T
```

unsafe fn init(init: <T as Pointable>::Init) -> usize

unsafe fn deref<'a>(ptr: usize) -> &'a T

unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

```
unsafe fn drop(ptr: usize)
```

`impl Pointee for RootMotionDelta`

```
type Metadata = ()
```

`impl Read for RootMotionDelta`

`impl<R> ReadPrimitive for RootMotionDelta`

`impl StructuralPartialEq for RootMotionDelta`

`impl WithSubscriber for RootMotionDelta`

Enums

`RootMotionError`

enum RootMotionError {
    PoseLength {
        previous: usize,
        current: usize,
    },
    RootNodeOutOfRange {
        root_node: usize,
        pose_len: usize,
    },
}

Defined in crates/byte-engine/src/animation/root_motion.rs:107-122

Errors returned when root motion cannot be extracted from a pose pair.

Variants

PoseLength

The previous and current poses have different node counts.
RootNodeOutOfRange

The selected root node is outside the pose.

Trait Implementations

`impl ArchivePointee for RootMotionError`

```
type ArchivedMetadata = ()
```

fn pointer_metadata(_: &<T as ArchivePointee>::ArchivedMetadata) -> <T as Pointee>::Metadata

`impl<ST> CastableFrom for RootMotionError`

`impl Clone for RootMotionError`

```
fn clone(&self) -> RootMotionError
```
Related: RootMotionError

`impl Copy for RootMotionError`

`impl Debug for RootMotionError`

fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result

`impl Display for RootMotionError`

fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result

`impl Downcast for RootMotionError`

fn into_any(self: Box<T>) -> Box<dyn Any>

fn into_any_rc(self: Rc<T>) -> Rc<dyn Any>

```
fn as_any(&self) -> &dyn Any
```

fn as_any_mut(&mut self) -> &mut dyn Any

`impl DowncastSend for RootMotionError`

fn into_any_send(self: Box<T>) -> Box<dyn Any + Send>

`impl DowncastSync for RootMotionError`

fn into_any_arc(self: Arc<T>) -> Arc<dyn Any + Sync + Send>

`impl Eq for RootMotionError`

`impl<K> Equivalent for RootMotionError`

```
fn equivalent(&self, key: &K) -> bool
```

`impl Error for RootMotionError`

`impl Instrument for RootMotionError`

`impl LayoutRaw for RootMotionError`

fn layout_raw(_: <T as Pointee>::Metadata) -> Result<Layout, LayoutError>

`impl<T, N1> Niching for RootMotionError`

unsafe fn is_niched(niched: *const NichedOption<T, N1>) -> bool

fn resolve_niched(out: Place<NichedOption<T, N1>>)

`impl PartialEq for RootMotionError`

fn eq(&self, other: &RootMotionError) -> bool

Related: RootMotionError

`impl Pointable for RootMotionError`

```
const ALIGN: usize
```
```
type Init = T
```

unsafe fn init(init: <T as Pointable>::Init) -> usize

unsafe fn deref<'a>(ptr: usize) -> &'a T

unsafe fn deref_mut<'a>(ptr: usize) -> &'a mut T

```
unsafe fn drop(ptr: usize)
```

`impl Pointee for RootMotionError`

```
type Metadata = ()
```

`impl Read for RootMotionError`

`impl StructuralPartialEq for RootMotionError`

`impl ToString for RootMotionError`

```
fn to_string(&self) -> String
```

`impl WithSubscriber for RootMotionError`

Functions

`extract_root_motion`

fn extract_root_motion(previous_pose: &[resource_management::resources::skeleton::LocalTransform], current_pose: &mut [resource_management::resources::skeleton::LocalTransform], root_node: usize, reference: resource_management::resources::skeleton::LocalTransform) -> Result<RootMotionDelta, RootMotionError>

Defined in crates/byte-engine/src/animation/root_motion.rs:65-93

Extracts one root node's motion and resets its translation and rotation to a reference pose.

Keep previous_pose unmodified between frames. The current root keeps its sampled scale because scale is not locomotion.

`forward_loop_root_motion`

fn forward_loop_root_motion(previous: resource_management::resources::skeleton::LocalTransform, loop_end: resource_management::resources::skeleton::LocalTransform, loop_start: resource_management::resources::skeleton::LocalTransform, current: resource_management::resources::skeleton::LocalTransform) -> RootMotionDelta

Defined in crates/byte-engine/src/animation/root_motion.rs:96-103

Calculates a forward loop-wrap delta by joining the end and start segments.

root_motion

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