Method ComputeWorldTransformMatrix
ComputeWorldTransformMatrix(in Entity, out float4x4, ref ComponentLookup<LocalTransform>, ref ComponentLookup<Parent>, ref ComponentLookup<PostTransformMatrix>)
Synchronously compute a local-to-world transformation matrix for an entity, using the current values of LocalTransform and PostTransformMatrix for the target entity and its hierarchy ancestors.
Declaration
[BurstCompile]
public static void ComputeWorldTransformMatrix(in Entity entity, out float4x4 outputMatrix, ref ComponentLookup<LocalTransform> localTransformLookup, ref ComponentLookup<Parent> parentLookup, ref ComponentLookup<PostTransformMatrix> scaleLookup)Parameters
| Type | Name | Description |
|---|---|---|
| Entity | entity | The entity whose world-space transform should be computed. |
| float4x4 | outputMatrix | If successful, the output world-space transformation matrix will be stored here. |
| ComponentLookup<LocalTransform> | localTransformLookup | Required to access the current transform values for |
| ComponentLookup<Parent> | parentLookup | Required to access the current parent for |
| ComponentLookup<PostTransformMatrix> | scaleLookup | Required to access the current non-uniform scale values for |
Remarks
This method is intended for the relatively uncommon cases where an entity's accurate world-space transformation matrix is needed immediately. For example:
- When performing a raycast from an entity which may be part of an entity hierarchy, such as the wheel of a car object. The ray origin must be in world-space, but the entity's LocalTransform may be relative to its parent.
- When one entity's transform needs to "track" another in world-space, and the targeting entity and/or the targeted entity are in a transform hierarchy.
- When an entity's transform is modified in the LateSimulationSystemGroup (after the TransformSystemGroup has updated, but before the PresentationSystemGroup runs), this method can be used to compute a new LocalToWorld value for the affected entity.
For an entity that is not part of an entity hierarchy, the LocalTransform component already stores the world-space transform (since the two spaces are identical). In his case, reading LocalTransform directly is more efficient than calling this method.
The LocalToWorld component also contains a world-space transformation matrix. However, this value may be out of date or invalid; it is only updated when the TransformSystemGroup runs). It may also contain additional offsets applied for graphical smoothing purposes. Therefore, while the LocalToWorld component may be useful as a fast approximation when its latency is acceptable, it should not be relied one when an accurate, up-to-date world transform is needed for simulation purposes.
This method's running time scales with the depth of the target entity is in its hierarchy.
Exceptions
| Type | Condition |
|---|---|
| InvalidOperationException | Thrown if |