pygfx.utils.transform.AffineTransform

class pygfx.utils.transform.AffineTransform(position=(0, 0, 0), rotation=(0, 0, 0, 1), scale=(1, 1, 1), *, reference_up=(0, 1, 0), is_camera_space=False, state_basis='components', matrix: ndarray = None)

Bases: AffineBase

A single affine transform.

Parameters:

• position (ndarray, [3]) – The position of this transform expressed in the target frame. This argument is only consumed if state_basis is set to “components”.

• rotation (ndarray, [4]) – The rotation quaternion of this transform expressed in the target frame. This argument is only consumed if state_basis is set to “components”.

• scale (ndarray, [3]) – The per-axis scale of this transform expressed in the target frame. This argument is only consumed if state_basis is set to “components”.

• reference_up (ndarray, [3]) – The direction of the reference_up vector expressed in the target frame. It indicates neutral tilt and is used by the axis properties (right, up, forward) to maintain a common level of rotation around an axis when it is updated by it’s setter. By default, it points along the Y-axis.

• is_camera_space (bool) – If True, the transform represents a camera space which means that it’s forward and right directions are inverted.

• state_basis (str) – One of “components” or “matrix”. The default is “components”. If “components”, the transform will store its state in the form of position, rotation, and scale, while the matrix will be computed. If “matrix”, the transform will store its state in the form of a matrix, while the position, rotation and scale will be computed. This option is provided to allow for performance optimizations when the transform is used in a context where the state is updated in one form but queried in another. Depending on your usage patterns, you may avoid significant overhead by choosing the appropriate basis.

• matrix (ndarray, [4, 4]) – The affine matrix describing this transform. This argument is only consumed if state_basis is set to “matrix”.

Notes

When updating the underlying numpy arrays in-place these updates will not propagate via the transform’s callback system nor will they invalidate existing caches. To inform the transform of these updates call transform.flag_update(), which will trigger both callbacks and cache invalidation.

See also

AffineBase

Base class defining various useful properties for this transform.

flag_update()

Signal that this transform has updated.

property reference_up: ndarray

The zero-tilt reference vector used for the direction setters.

property state_basis: str

The basis of the transform, either “components” (default) or “matrix”.

property position: ndarray

The origin of source.

property rotation: ndarray

The orientation of source as a quaternion.

property scale: ndarray

The scale of source.

property scaling_signs: ndarray

Property used to track and preserve the scale factor signs over matrix decomposition operations.

property rotation_matrix: ndarray

The orientation of source as a rotation matrix.

property euler: ndarray

The orientation of source as XYZ euler angles.

property matrix: ndarray

Affine matrix describing this transform.

vec_target = matrix @ vec_source.

Examples

Culling

Culling