Class MatrixScaleHelper

Extraction and application of the per-axis scale stored in a Unity.Transforms.PostTransformMatrix or in a Unity.Transforms.LocalToWorld's float4x4 TransformHelpers.Scale can't be used for this: it returns unsigned lengths, losing mirrored axes.

Inheritance

object

MatrixScaleHelper

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

Namespace: Unity.Netcode

Assembly: Unity.NetCode.dll

Syntax

public static class MatrixScaleHelper

Remarks

A matrix does not uniquely encode which axes are mirrored, so SignedScaleFromScaleOnlyMatrix(in float4x4) takes the per-axis signs from the diagonal. That is faithful for scale-only matrices, and pairs with a rotation coming from elsewhere (e.g. the replicated Unity.Transforms.LocalTransform.Rotation) rather than one orthonormalized out of the same matrix - a quaternion cannot carry a mirror, so that would invent a rotation instead. If the matrix does carry its own rotation, diagonal signs it turns negative (rotations past 90°) are read - and on SetScale(in float4x4, float3), overwritten - as scale signs. Adapt to the convention: read/write scale through this helper and author mirroring as negative scale, not as 180° rotations.

Methods

SetScale(in float4x4, float3)

Replaces the matrix's per-axis signed scale (per SignedScaleFromScaleOnlyMatrix(in float4x4)'s convention), preserving its rotation and translation.

Declaration

public static float4x4 SetScale(in float4x4 matrix, float3 newScale)

Parameters

Type	Name	Description
float4x4	matrix	The matrix to re-scale.
float3	newScale	The new per-axis scale. Negative values mirror the axis.

Returns

Type	Description
float4x4	A matrix with the requested scale and the original rotation/translation.

SignedScaleFromScaleOnlyMatrix(in float4x4)

The signed per-axis scale: column lengths, signs from the matrix diagonal. Only faithful for scale-only matrices (see class remarks).

Declaration

public static float3 SignedScaleFromScaleOnlyMatrix(in float4x4 matrix)

Parameters

Type	Name	Description
float4x4	matrix	The matrix to extract the scale from.

Returns

Type	Description
float3	The signed per-axis scale.