UBlendSpace

class Engine Blueprint Since 4.0

Inherits: UObjectBase › UObjectBaseUtility › UObject › UAnimationAsset › UBlendSpace

#include "Animation/BlendSpace.h"

Description

An animation asset that blends between multiple animation sequences based on one or two float parameters (e.g. Speed and Direction for locomotion).

Caveats & Gotchas

• BlendSpaces are evaluated inside the Anim Blueprint graph, not called directly in C++. Reference them as UPROPERTY assets and assign them to BlendSpace graph nodes.
• For 1D blending (single axis), use UBlendSpace1D. UBlendSpace supports up to 2 axes.
• Sample points must be distributed across the parameter range — avoid clustering samples or the interpolation will be inaccurate.

Example

Reference a BlendSpace in C++ C++

UPROPERTY(EditDefaultsOnly, Category="Animation")
UBlendSpace* LocomotionBlendSpace;

// Assign to an anim graph node in the AnimBP, or use
// USkeletalMeshComponent::SetBlendSpaceInput() variants.

Functions (22)

Utility 1 Filtering 3 Interpolation 2 Playback 3 Samples 8 Sampling 5

Utility

1 ▼

Access	Type	Name	Description
public	function	UBlendSpace::GetResourceSizeEx	Reports the blend space's estimated memory footprint by accumulating into CumulativeResourceSize, overriding UObject::GetResourceSizeEx.

Filtering

3 ▼

Access	Type	Name	Description
public	function	UBlendSpace::FilterInput	Smooths a raw blend input over time using the given filter's InterpolationParam settings, returning the filtered position to sample with.
public	function	UBlendSpace::InitializeFilter	Sets up runtime filtering state for smoothing blend input, using this blend space's InterpolationParam settings.
public	function	UBlendSpace::UpdateFilterParams	Refreshes an existing filter's smoothing parameters from the current InterpolationParam settings without a full re-initialization.

Interpolation

2 ▼

Access	Type	Name	Description
public	function	UBlendSpace::GetPerBoneInterpolationData	Sorts the blend space's per-bone blend settings into a lookup structure for Skeleton, so GetPerBoneInterpolationIndex can be queried repeatedly and cheaply for that skeleton.
public	function	UBlendSpace::GetPerBoneInterpolationIndex	Looks up the per-bone interpolation index for a bone within the pose being evaluated, returning INDEX_NONE if the bone has no per-bone smoothing override.

Playback

3 ▼

Access	Type	Name	Description
public	function	UBlendSpace::GetAnimationPose	Extracts a blended pose into OutAnimationPoseData by evaluating each sample in BlendSampleDataCache and combining them according to their weights.
public	function	UBlendSpace::GetPlayLength	Always returns 1.
public	function	UBlendSpace::TickAssetPlayer	Advances the blend space's sample weights and internal playback position for one tick, overriding UAnimationAsset's asset-player tick.

Samples

8 ▼

Access	Type	Name	Description
public	function	UBlendSpace::ForEachImmutableSample	Iterates through every data sample in the blend space, invoking the given function for each one without exposing the underlying array.
public	function	UBlendSpace::GetAnimationLengthFromSampleData	Computes the effective animation length for a weighted set of blend samples, accounting for each sample's rate scale.
public	function	UBlendSpace::GetBlendSample	Returns the blend sample at the given index.
public	function	UBlendSpace::GetBlendSamples	Returns the full array of blend samples (animation + sample position + rate scale) configured on this blend space asset.
public	function	UBlendSpace::GetClampedAndWrappedBlendInput	Clamps each axis of a blend input to its configured range, wrapping instead of clamping for any axis marked as wrapping (e.
public	function	UBlendSpace::GetSamplesFromBlendInput	Resolves which grid samples and weights apply for a given blend input position, driving the actual pose blend.
public	function	UBlendSpace::ResetBlendSamples	Resets a cached set of blend samples to a given normalized time, advancing each sample using sync markers where possible instead of just resetting a raw time value.
public	function	UBlendSpace::UpdateBlendSamples	Advances a cached set of blend samples for one tick, given a new blend space position and delta time.

Sampling

5 ▼

Access	Type	Name	Description
public	function	UBlendSpace::GetBlendParameter	Returns the axis configuration — name, range, and grid divisions — for blend parameter Index.
public	function	UBlendSpace::IsValidAdditive	Returns whether the blend space is set up as an additive animation, based on its samples' additive settings.
public	function	UBlendSpace::IsValidAdditiveType	Returns whether AdditiveType is compatible with this blend space's configured additive setup.
public	function	UBlendSpace::ComputeAxisScaleFactor	Computes the scale factor applied to sample playback rate on axes configured to scale animation, based on the ratio between the raw and filtered blend space position.
public	function	UBlendSpace::GetUniqueMarkerNames	Returns the set of unique sync marker names referenced across all animation samples in the blend space, used for marker-based animation syncing.

Properties

Access	Type	Name	Description
public	property	UBlendSpace::AnimLength	The maximum length, in seconds, of any single sample contained in this blend space.
public	property	UBlendSpace::NotifyTriggerMode	Controls which contributing animations are allowed to fire anim notifies while blended: all of them, only the highest-weighted one, or none.
public	property	UBlendSpace::PreferredTriangulationDirection	Preferred edge direction the triangulator uses when it has to make an arbitrary choice while splitting rectangular grid cells.
public	property	UBlendSpace::TargetWeightInterpolationSpeedPerSec	Speed at which individual sample weights are allowed to change per second, letting the blend space jump directly between extremes instead of smoothly passing through intermediate positions.
public	property	UBlendSpace::bAllowMarkerBasedSync	Whether samples within this blend space are allowed to sync against each other using animation sync markers.
public	property	UBlendSpace::bAllowMeshSpaceBlending	Enables mesh-space blending when per-bone sample smoothing overrides are in use, so different parts of the skeleton can reach their target pose at different speeds — for example, letting the head turn toward an aim target faster than the body.
public	property	UBlendSpace::bContainsRotationOffsetMeshSpaceSamples	Cached flag indicating whether any sample in the blend space has rotation offsets that must be applied in mesh space rather than local space.
public	property	UBlendSpace::bInterpolateUsingGrid	If true, runtime interpolation is done via the precomputed grid instead of the raw triangulation/segmentation.
public	property	UBlendSpace::bLoop	The default looping behaviour of this blend space when played as an animation asset.
public	property	UBlendSpace::bShouldMatchSyncPhases	If true, follower samples pass the same number of sync markers as the leader sample to match its sync phase exactly; otherwise they only match their nearest valid sync position.
public	property	UBlendSpace::bTargetWeightInterpolationEaseInOut	If set, eases sample weight adjustments in and out rather than moving at a constant rate, using TargetWeightInterpolationSpeedPerSec to determine the amount of smoothing.

Version History

Introduced in: 4.0

Version	Status	Notes
5.6	stable	—

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