Struct Transform

pub struct Transform {
    pub translation: Vec3,
    pub rotation: Quat,
    pub scale: Vec3,
}

Describe the position of an entity. If the entity has a parent, the position is relative to its parent position.

• To place or move an entity, you should set its Transform.
• To get the global transform of an entity, you should get its GlobalTransform.
• To be displayed, an entity must have both a Transform and a GlobalTransform.
  • You may use the TransformBundle to guarantee this.

Transform and GlobalTransform

Transform is the position of an entity relative to its parent position, or the reference frame if it doesn’t have a Parent.

GlobalTransform is the position of an entity relative to the reference frame.

GlobalTransform is updated from Transform by systems in the system set TransformPropagate.

This system runs during PostUpdate. If you update the Transform of an entity during this set or after, you will notice a 1 frame lag before the GlobalTransform is updated.

Examples

• transform

Fields

translation: Vec3

Position of the entity. In 2d, the last value of the Vec3 is used for z-ordering.

See the translations example for usage.

rotation: Quat

Rotation of the entity.

See the 3d_rotation example for usage.

scale: Vec3

Scale of the entity.

See the scale example for usage.

Implementations

impl Transform

pub const IDENTITY: Self = _

An identity Transform with no translation, rotation, and a scale of 1 on all axes.

pub const fn from_xyz(x: f32, y: f32, z: f32) -> Self

Creates a new Transform at the position (x, y, z). In 2d, the z component is used for z-ordering elements: higher z-value will be in front of lower z-value.

pub fn from_matrix(world_from_local: Mat4) -> Self

Extracts the translation, rotation, and scale from matrix. It must be a 3d affine transformation matrix.

pub const fn from_translation(translation: Vec3) -> Self

Creates a new Transform, with translation. Rotation will be 0 and scale 1 on all axes.

pub const fn from_rotation(rotation: Quat) -> Self

Creates a new Transform, with rotation. Translation will be 0 and scale 1 on all axes.

pub const fn from_scale(scale: Vec3) -> Self

Creates a new Transform, with scale. Translation will be 0 and rotation 0 on all axes.

pub fn looking_at(self, target: Vec3, up: impl TryInto<Dir3>) -> Self

Returns this Transform with a new rotation so that Transform::forward points towards the target position and Transform::up points towards up.

In some cases it’s not possible to construct a rotation. Another axis will be picked in those cases:

• if target is the same as the transform translation, Vec3::Z is used instead
• if up fails converting to Dir3 (e.g if it is Vec3::ZERO), Dir3::Y is used instead
• if the resulting forward direction is parallel with up, an orthogonal vector is used as the “right” direction

pub fn looking_to( self, direction: impl TryInto<Dir3>, up: impl TryInto<Dir3>, ) -> Self

Returns this Transform with a new rotation so that Transform::forward points in the given direction and Transform::up points towards up.

In some cases it’s not possible to construct a rotation. Another axis will be picked in those cases:

• if direction fails converting to Dir3 (e.g if it is Vec3::ZERO), Dir3::Z is used instead
• if up fails converting to Dir3, Dir3::Y is used instead
• if direction is parallel with up, an orthogonal vector is used as the “right” direction

pub fn aligned_by( self, main_axis: impl TryInto<Dir3>, main_direction: impl TryInto<Dir3>, secondary_axis: impl TryInto<Dir3>, secondary_direction: impl TryInto<Dir3>, ) -> Self

Rotates this Transform so that the main_axis vector, reinterpreted in local coordinates, points in the given main_direction, while secondary_axis points towards secondary_direction. For example, if a spaceship model has its nose pointing in the X-direction in its own local coordinates and its dorsal fin pointing in the Y-direction, then align(Dir3::X, v, Dir3::Y, w) will make the spaceship’s nose point in the direction of v, while the dorsal fin does its best to point in the direction w.

In some cases a rotation cannot be constructed. Another axis will be picked in those cases:

• if main_axis or main_direction fail converting to Dir3 (e.g are zero), Dir3::X takes their place
• if secondary_axis or secondary_direction fail converting, Dir3::Y takes their place
• if main_axis is parallel with secondary_axis or main_direction is parallel with secondary_direction, a rotation is constructed which takes main_axis to main_direction along a great circle, ignoring the secondary counterparts

See Transform::align for additional details.

pub const fn with_translation(self, translation: Vec3) -> Self

Returns this Transform with a new translation.

pub const fn with_rotation(self, rotation: Quat) -> Self

Returns this Transform with a new rotation.

pub const fn with_scale(self, scale: Vec3) -> Self

Returns this Transform with a new scale.

pub fn compute_matrix(&self) -> Mat4

Returns the 3d affine transformation matrix from this transforms translation, rotation, and scale.

pub fn compute_affine(&self) -> Affine3A

Returns the 3d affine transformation matrix from this transforms translation, rotation, and scale.

pub fn local_x(&self) -> Dir3

Get the unit vector in the local X direction.

pub fn left(&self) -> Dir3

Equivalent to -local_x()

pub fn right(&self) -> Dir3

Equivalent to local_x()

pub fn local_y(&self) -> Dir3

Get the unit vector in the local Y direction.

pub fn up(&self) -> Dir3

Equivalent to local_y()

pub fn down(&self) -> Dir3

Equivalent to -local_y()

pub fn local_z(&self) -> Dir3

Get the unit vector in the local Z direction.

pub fn forward(&self) -> Dir3

Equivalent to -local_z()

pub fn back(&self) -> Dir3

Equivalent to local_z()

pub fn rotate(&mut self, rotation: Quat)

Rotates this Transform by the given rotation.

If this Transform has a parent, the rotation is relative to the rotation of the parent.

Examples

• 3d_rotation

pub fn rotate_axis(&mut self, axis: Dir3, angle: f32)

Rotates this Transform around the given axis by angle (in radians).

If this Transform has a parent, the axis is relative to the rotation of the parent.

pub fn rotate_x(&mut self, angle: f32)

Rotates this Transform around the X axis by angle (in radians).

If this Transform has a parent, the axis is relative to the rotation of the parent.

pub fn rotate_y(&mut self, angle: f32)

Rotates this Transform around the Y axis by angle (in radians).

If this Transform has a parent, the axis is relative to the rotation of the parent.

pub fn rotate_z(&mut self, angle: f32)

Rotates this Transform around the Z axis by angle (in radians).

If this Transform has a parent, the axis is relative to the rotation of the parent.

pub fn rotate_local(&mut self, rotation: Quat)

Rotates this Transform by the given rotation.

The rotation is relative to this Transform’s current rotation.

pub fn rotate_local_axis(&mut self, axis: Dir3, angle: f32)

Rotates this Transform around its local axis by angle (in radians).

pub fn rotate_local_x(&mut self, angle: f32)

Rotates this Transform around its local X axis by angle (in radians).

pub fn rotate_local_y(&mut self, angle: f32)

Rotates this Transform around its local Y axis by angle (in radians).

pub fn rotate_local_z(&mut self, angle: f32)

Rotates this Transform around its local Z axis by angle (in radians).

pub fn translate_around(&mut self, point: Vec3, rotation: Quat)

Translates this Transform around a point in space.

If this Transform has a parent, the point is relative to the Transform of the parent.

pub fn rotate_around(&mut self, point: Vec3, rotation: Quat)

Rotates this Transform around a point in space.

If this Transform has a parent, the point is relative to the Transform of the parent.

pub fn look_at(&mut self, target: Vec3, up: impl TryInto<Dir3>)

Rotates this Transform so that Transform::forward points towards the target position, and Transform::up points towards up.

In some cases it’s not possible to construct a rotation. Another axis will be picked in those cases:

• if target is the same as the transform translation, Vec3::Z is used instead
• if up fails converting to Dir3 (e.g if it is Vec3::ZERO), Dir3::Y is used instead
• if the resulting forward direction is parallel with up, an orthogonal vector is used as the “right” direction

pub fn look_to(&mut self, direction: impl TryInto<Dir3>, up: impl TryInto<Dir3>)

Rotates this Transform so that Transform::forward points in the given direction and Transform::up points towards up.

In some cases it’s not possible to construct a rotation. Another axis will be picked in those cases:

• if direction fails converting to Dir3 (e.g if it is Vec3::ZERO), Dir3::NEG_Z is used instead
• if up fails converting to Dir3, Dir3::Y is used instead
• if direction is parallel with up, an orthogonal vector is used as the “right” direction

pub fn align( &mut self, main_axis: impl TryInto<Dir3>, main_direction: impl TryInto<Dir3>, secondary_axis: impl TryInto<Dir3>, secondary_direction: impl TryInto<Dir3>, )

Rotates this Transform so that the main_axis vector, reinterpreted in local coordinates, points in the given main_direction, while secondary_axis points towards secondary_direction.

For example, if a spaceship model has its nose pointing in the X-direction in its own local coordinates and its dorsal fin pointing in the Y-direction, then align(Dir3::X, v, Dir3::Y, w) will make the spaceship’s nose point in the direction of v, while the dorsal fin does its best to point in the direction w.

More precisely, the Transform::rotation produced will be such that:

• applying it to main_axis results in main_direction
• applying it to secondary_axis produces a vector that lies in the half-plane generated by main_direction and secondary_direction (with positive contribution by secondary_direction)

Transform::look_to is recovered, for instance, when main_axis is Dir3::NEG_Z (the Transform::forward direction in the default orientation) and secondary_axis is Dir3::Y (the Transform::up direction in the default orientation). (Failure cases may differ somewhat.)

In some cases a rotation cannot be constructed. Another axis will be picked in those cases:

• if main_axis or main_direction fail converting to Dir3 (e.g are zero), Dir3::X takes their place
• if secondary_axis or secondary_direction fail converting, Dir3::Y takes their place
• if main_axis is parallel with secondary_axis or main_direction is parallel with secondary_direction, a rotation is constructed which takes main_axis to main_direction along a great circle, ignoring the secondary counterparts

Example

t1.align(Dir3::X, Dir3::Y, Vec3::new(1., 1., 0.), Dir3::Z);
let main_axis_image = t1.rotation * Dir3::X;
let secondary_axis_image = t1.rotation * Vec3::new(1., 1., 0.);
assert!(main_axis_image.abs_diff_eq(Vec3::Y, 1e-5));
assert!(secondary_axis_image.abs_diff_eq(Vec3::new(0., 1., 1.), 1e-5));

t1.align(Vec3::ZERO, Dir3::Z, Vec3::ZERO, Dir3::X);
t2.align(Dir3::X, Dir3::Z, Dir3::Y, Dir3::X);
assert_eq!(t1.rotation, t2.rotation);

t1.align(Dir3::X, Dir3::Z, Dir3::X, Dir3::Y);
assert_eq!(t1.rotation, Quat::from_rotation_arc(Vec3::X, Vec3::Z));

pub fn mul_transform(&self, transform: Transform) -> Self

Multiplies self with transform component by component, returning the resulting Transform

pub fn transform_point(&self, point: Vec3) -> Vec3

Transforms the given point, applying scale, rotation and translation.

If this Transform has a parent, this will transform a point that is relative to the parent’s Transform into one relative to this Transform.

If this Transform does not have a parent, this will transform a point that is in global space into one relative to this Transform.

If you want to transform a point in global space to the local space of this Transform, consider using GlobalTransform::transform_point() instead.

pub fn is_finite(&self) -> bool

Returns true if, and only if, translation, rotation and scale all are finite. If any of them contains a NaN, positive or negative infinity, this will return false.

Trait Implementations

impl Clone for Transform

fn clone(&self) -> Transform

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Component for Transform

where Self: Send + Sync + 'static,

const STORAGE_TYPE: StorageType = bevy_ecs::component::StorageType::Table

A constant indicating the storage type used for this component.

fn register_component_hooks(_hooks: &mut ComponentHooks)

Called when registering this component, allowing mutable access to its ComponentHooks.

impl Debug for Transform

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

Formats the value using the given formatter.

impl Default for Transform

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Transform

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl From<GlobalTransform> for Transform

The transform is expected to be non-degenerate and without shearing, or the output will be invalid.

fn from(transform: GlobalTransform) -> Self

Converts to this type from the input type.

impl From<Transform> for GlobalTransform

fn from(transform: Transform) -> Self

Converts to this type from the input type.

impl From<Transform> for TransformBundle

Available on crate feature bevy-support only.

fn from(transform: Transform) -> Self

Converts to this type from the input type.

impl FromReflect for Transform

where Self: Any + Send + Sync, Vec3: FromReflect + TypePath + RegisterForReflection, Quat: FromReflect + TypePath + RegisterForReflection,

fn from_reflect(reflect: &dyn Reflect) -> Option<Self>

Constructs a concrete instance of Self from a reflected value.

fn take_from_reflect( reflect: Box<dyn Reflect>, ) -> Result<Self, Box<dyn Reflect>>

Attempts to downcast the given value to Self using, constructing the value using from_reflect if that fails.

impl GetTypeRegistration for Transform

where Self: Any + Send + Sync, Vec3: FromReflect + TypePath + RegisterForReflection, Quat: FromReflect + TypePath + RegisterForReflection,

fn get_type_registration() -> TypeRegistration

Returns the default TypeRegistration for this type.

fn register_type_dependencies(registry: &mut TypeRegistry)

Registers other types needed by this type.

impl Mul<GlobalTransform> for Transform

type Output = GlobalTransform

The resulting type after applying the * operator.

fn mul(self, global_transform: GlobalTransform) -> Self::Output

Performs the * operation.

impl Mul<Transform> for GlobalTransform

type Output = GlobalTransform

The resulting type after applying the * operator.

fn mul(self, transform: Transform) -> Self::Output

Performs the * operation.

impl Mul<Vec3> for Transform

type Output = Vec3

The resulting type after applying the * operator.

fn mul(self, value: Vec3) -> Self::Output

Performs the * operation.

impl Mul for Transform

type Output = Transform

The resulting type after applying the * operator.

fn mul(self, transform: Transform) -> Self::Output

Performs the * operation.

impl PartialEq for Transform

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

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Reflect for Transform

where Self: Any + Send + Sync, Vec3: FromReflect + TypePath + RegisterForReflection, Quat: FromReflect + TypePath + RegisterForReflection,

fn get_represented_type_info(&self) -> Option<&'static TypeInfo>

Returns the TypeInfo of the type represented by this value.

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

Returns the value as a Box<dyn Any>.

fn as_any(&self) -> &dyn Any

Returns the value as a &dyn Any.

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

Returns the value as a &mut dyn Any.

fn into_reflect(self: Box<Self>) -> Box<dyn Reflect>

Casts this type to a boxed reflected value.

fn as_reflect(&self) -> &dyn Reflect

Casts this type to a reflected value.

fn as_reflect_mut(&mut self) -> &mut dyn Reflect

Casts this type to a mutable reflected value.

fn clone_value(&self) -> Box<dyn Reflect>

Clones the value as a Reflect trait object.

fn set(&mut self, value: Box<dyn Reflect>) -> Result<(), Box<dyn Reflect>>

Performs a type-checked assignment of a reflected value to this value.

fn try_apply(&mut self, value: &dyn Reflect) -> Result<(), ApplyError>

Tries to apply a reflected value to this value.

fn reflect_kind(&self) -> ReflectKind

Returns a zero-sized enumeration of “kinds” of type.

fn reflect_ref(&self) -> ReflectRef<'_>

Returns an immutable enumeration of “kinds” of type.

fn reflect_mut(&mut self) -> ReflectMut<'_>

Returns a mutable enumeration of “kinds” of type.

fn reflect_owned(self: Box<Self>) -> ReflectOwned

Returns an owned enumeration of “kinds” of type.

fn reflect_partial_eq(&self, value: &dyn Reflect) -> Option<bool>

Returns a “partial equality” comparison result.

fn apply(&mut self, value: &(dyn Reflect + 'static))

Applies a reflected value to this value.

fn reflect_hash(&self) -> Option<u64>

Returns a hash of the value (which includes the type).

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

Debug formatter for the value.

fn serializable(&self) -> Option<Serializable<'_>>

Returns a serializable version of the value.

fn is_dynamic(&self) -> bool

Indicates whether or not this type is a dynamic type.

impl Serialize for Transform

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Struct for Transform

where Self: Any + Send + Sync, Vec3: FromReflect + TypePath + RegisterForReflection, Quat: FromReflect + TypePath + RegisterForReflection,

fn field(&self, name: &str) -> Option<&dyn Reflect>

Returns a reference to the value of the field named name as a &dyn Reflect.

fn field_mut(&mut self, name: &str) -> Option<&mut dyn Reflect>

Returns a mutable reference to the value of the field named name as a &mut dyn Reflect.

fn field_at(&self, index: usize) -> Option<&dyn Reflect>

Returns a reference to the value of the field with index index as a &dyn Reflect.

fn field_at_mut(&mut self, index: usize) -> Option<&mut dyn Reflect>

Returns a mutable reference to the value of the field with index index as a &mut dyn Reflect.

fn name_at(&self, index: usize) -> Option<&str>

Returns the name of the field with index index.

fn field_len(&self) -> usize

Returns the number of fields in the struct.

fn iter_fields(&self) -> FieldIter<'_>

Returns an iterator over the values of the reflectable fields for this struct.

fn clone_dynamic(&self) -> DynamicStruct

Clones the struct into a DynamicStruct.

impl TransformPoint for Transform

fn transform_point(&self, point: impl Into<Vec3>) -> Vec3

Transform a point.

impl TypePath for Transform

where Self: Any + Send + Sync,

fn type_path() -> &'static str

Returns the fully qualified path of the underlying type.

fn short_type_path() -> &'static str

Returns a short, pretty-print enabled path to the type.

fn type_ident() -> Option<&'static str>

Returns the name of the type, or None if it is anonymous.

fn crate_name() -> Option<&'static str>

Returns the name of the crate the type is in, or None if it is anonymous.

fn module_path() -> Option<&'static str>

Returns the path to the module the type is in, or None if it is anonymous.

impl Typed for Transform

where Self: Any + Send + Sync, Vec3: FromReflect + TypePath + RegisterForReflection, Quat: FromReflect + TypePath + RegisterForReflection,

fn type_info() -> &'static TypeInfo

Returns the compile-time info for the underlying type.

impl Copy for Transform

impl StructuralPartialEq for Transform