Struct Posture

pub struct Posture<T: Scalar> { /* private fields */ }

Collection of bones transformations that represent a skelly posture.

It’s primary usecase is to be used instead of transformations contained in the Skelly. Multiple postures to be processed for the same Skelly. Allowing running animations, IK algorithms etc, and then blend them to get final posture.

Implementations

impl<T> Posture<T>

where T: Scalar,

pub fn new<D>(skelly: &Skelly<T, D>) -> Self

where T: RealField,

Returns new Posture instance for skelly. Copies current skelly transformations.

Example

let mut skelly = Skelly::<f32>::new();
let root = skelly.add_root(Point3::origin());
let bone = skelly.attach(Vector3::x(), root);

let mut posture = Posture::new(&skelly);

pub fn is_compatible<D>(&self, skelly: &Skelly<T, D>) -> bool

pub fn append_rotation(&mut self, bone: usize, rotation: UnitQuaternion<T>)

where T: RealField,

Rotates bone with specified id.

Does not affect relative position to the parent and global position for root bones. Affects global position of all descendant bones.

Example

let mut skelly = Skelly::<f32>::new();
let root = skelly.add_root(Point3::origin());
let bone = skelly.attach(Vector3::x(), root);

let mut posture = Posture::new(&skelly);

let mut globals = [Isometry3::identity(); 2];
posture.write_globals(&skelly, &Isometry3::identity(), &mut globals);
let bone_global_old = globals[bone];

// Ensure that bone is placed correctly in global space at (1, 0, 0).
assert!((bone_global_old.translation.vector - Vector3::x()).magnitude() < EPSILON);

// Rotate root bone. It is still at origin.
// Yet global position of the `bone` attached to `root` has changed accordingly.
posture.append_rotation(root, UnitQuaternion::from_euler_angles(0.0, 0.0, PI / 2.0));

posture.write_globals(&skelly, &Isometry3::identity(), &mut globals);
let bone_global_new = globals[bone];

// Ensure that bone is placed correctly in global space after root rotation at (0, 1, 0).
assert!((bone_global_new.translation.vector - Vector3::y()).magnitude() < EPSILON);

Panics

This method panics if bone index is out of bounds.

pub fn prepend_rotation(&mut self, bone: usize, rotation: UnitQuaternion<T>)

where T: RealField,

Rotates bone with specified id.

Does not affect relative position to the parent and global position for root bones. Affects global position of all descendant bones.

Example

let mut skelly = Skelly::<f32>::new();
let root = skelly.add_root(Point3::origin());
let bone = skelly.attach(Vector3::x(), root);

let mut posture = Posture::new(&skelly);

let mut globals = [Isometry3::identity(); 2];
posture.write_globals(&skelly, &Isometry3::identity(), &mut globals);
let bone_global_old = globals[bone];

// Ensure that bone is placed correctly in global space at (1, 0, 0).
assert!((bone_global_old.translation.vector - Vector3::x()).magnitude() < EPSILON);

// Rotate the bone. It is still at origin.
// Yet global position of the `bone` attached to `root` has changed accordingly.
posture.prepend_rotation(bone, UnitQuaternion::from_euler_angles(0.0, 0.0, PI / 2.0));

posture.write_globals(&skelly, &Isometry3::identity(), &mut globals);
let bone_global_new = globals[bone];

// Ensure that bone is placed correctly in global space after root rotation at (0, 1, 0).
assert!((bone_global_new.translation.vector - Vector3::y()).magnitude() < EPSILON);

Panics

This method panics if bone index is out of bounds.

pub fn append_translation(&mut self, bone: usize, translation: Translation3<T>)

where T: RealField,

Translates bone with specified id.

Affects relative position to the parent and global position for root bones. Affects global position of all descendant bones.

Example

let mut skelly = Skelly::<f32>::new();
let root = skelly.add_root(Point3::origin());
let bone = skelly.attach(Vector3::x(), root);

let mut posture = Posture::new(&skelly);

let mut globals = [Isometry3::identity(); 2];
posture.write_globals(&skelly, &Isometry3::identity(), &mut globals);
let bone_global_old = globals[bone];

// Ensure that bone is placed correctly in global space at (1, 0, 0).
assert!((bone_global_old.translation.vector - Vector3::x()).magnitude() < EPSILON);

// Translate root bone.
// Global position of the `bone` attached to `root` has changed accordingly.
posture.append_translation(root, Vector3::z().into());

posture.write_globals(&skelly, &Isometry3::identity(), &mut globals);
let bone_global_new = globals[bone];

// Ensure that bone is placed correctly in global space after root translation at (1, 0, 1).
assert!((bone_global_new.translation.vector - (Vector3::x() + Vector3::z())).magnitude() < EPSILON);

Panics

This method panics if bone index is out of bounds.

pub fn set_position(&mut self, bone: usize, position: Vector3<T>)

Sets relative position for bone with specified id. Affects global position of all descendant bones.

This method ignores current relative position of the bone. To apply translation to current relative poistion see Skelly::append_translation.

Example

let mut skelly = Skelly::<f32>::new();
let root = skelly.add_root(Point3::origin());
let bone = skelly.attach(Vector3::x(), root);

let mut posture = Posture::new(&skelly);

let mut globals = [Isometry3::identity(); 2];
posture.write_globals(&skelly, &Isometry3::identity(), &mut globals);
let bone_global_old = globals[bone];

// Ensure that bone is placed correctly in global space at (1, 0, 0).
assert!((bone_global_old.translation.vector - Vector3::x()).magnitude() < EPSILON);

// Set new relative position for the `bone`.
posture.set_position(bone, Vector3::z());

posture.write_globals(&skelly, &Isometry3::identity(), &mut globals);
let bone_global_new = globals[bone];

// Ensure that bone is placed correctly in global space at new position (0, 0, 1).
assert!((bone_global_new.translation.vector - Vector3::z()).magnitude() < EPSILON);

Panics

This method panics if bone index is out of bounds.

pub fn get_position(&mut self, bone: usize) -> Vector3<T>

where T: RealField,

Returns current bone position relative to parent.

pub fn set_orientation(&mut self, bone: usize, orientation: UnitQuaternion<T>)

Sets relative orientation for bone with specified id. Affects global position of all descendant bones.

This method ignores current relative position of the bone. To apply translation to current relative poistion see Skelly::append_translation.

Example

let mut skelly = Skelly::<f32>::new();
let root = skelly.add_root(Point3::origin());
let bone = skelly.attach(Vector3::x(), root);

let mut posture = Posture::new(&skelly);

let mut globals = [Isometry3::identity(); 2];
posture.write_globals(&skelly, &Isometry3::identity(), &mut globals);
let bone_global_old = globals[bone];

// Ensure that bone is placed correctly in global space at (1, 0, 0).
assert!((bone_global_old.translation.vector - Vector3::x()).magnitude() < EPSILON);

// Set new relative orientation for the `bone`.
posture.set_orientation(root, UnitQuaternion::from_euler_angles(0.0, 0.0, PI / 2.0));

posture.write_globals(&skelly, &Isometry3::identity(), &mut globals);
let bone_global_new = globals[bone];

// Ensure that bone is placed correctly in global space at new position (0, 0, 1).
assert!((bone_global_new.translation.vector - Vector3::y()).magnitude() < EPSILON);

Panics

This method panics if bone index is out of bounds.

pub fn get_orientation(&mut self, bone: usize) -> UnitQuaternion<T>

where T: RealField,

Returns current bone orientation relative to parent.

pub fn get_isometry(&mut self, bone: usize) -> Isometry3<T>

where T: RealField,

Returns current bone isometry relative to parent.

pub fn write_globals<D>( &self, skelly: &Skelly<T, D>, skelly_global: &Isometry3<T>, globals: &mut [Isometry3<T>], )

where T: RealField,

Fills slice of Isometry3 with global isometries for each bone of the skelly in this posture.

Example

let mut skelly = Skelly::<f32>::new();
let root = skelly.add_root(Point3::origin());
let bone = skelly.attach(Vector3::x(), root);

let mut posture = Posture::new(&skelly);

// Animate the skelly by modifying posture iteratively.

let mut globals = [Isometry3::identity(); 2];
posture.write_globals(&skelly, &Isometry3::identity(), &mut globals);

Panics

Panics if this posture is not compatible with the skelly.
To check for compatibility use Posture::is_compatible.
One may use Posture with Skelly used to create that Posture (see Posture::new) as it is guaranteed to be compatible until new bone is added.