StartRecording

Overview

BloodStain recording and playback subsystem.

A GameInstanceSubsystem responsible for:

• Real-time recording of actor and component transforms
• Transform quantization and compression based on user settings
• Saving and loading replay data to local files with header/body caching
• Exposing Blueprint-callable APIs for recording and replay control

References

Plugin	BloodStainSystem
Module	BloodStainSystem
Header	#include "BloodStainSubSystem.h"
Source	/Plugins/BloodStainSystem/Source/BloodStainSystem/Private/BloodStainSubSystem.cpp
Super Class	UGameInstanceSubsystem

Properties

Type	Name	Description
FileSaveOptions	FBloodStainFileOptions	File’s save options.
OnCompleteBuildRecordingHeader	FOnBuildRecordingHeader	Just before saving the file, a broadcast is triggered. This can be used to modify or assign the header data.
TArray<TObjectPtr<ABloodStainActor>>	BloodStainActors	Spawned Blood Stains

Functions

Start Recording

Description

If the group is already recording, join the group
Record Component is Attached to the Target Actor

Notes – This does not handle the case where the Actor is already being recorded in another Group. If called in such a scenario, it will return false.

Inputs

Type	Name	Description
AActor*	Target Actor	The actor to record
FRecordOptions (Optional)	Options	Optional recording options

Outputs

Type	Name	Description
bool	Return Value	Whether the recording start is successful. If Actor is Already Recording for Target Group, return false.

Start Recording With Actors

Description

If the group is already recording, join the group
Record Component is Attached to the Target Actor

Notes – This does not handle the case where the Actor is already being recorded in another Group. If called in such a scenario, it will return false.

Inputs

Type	Name	Description
TArray<AActor*>	Target Actors	The actors to record
FRecordOptions (Optional)	Record Options	Optional recording options

Outputs

Type	Name	Description
bool	Return Value	whether the recording start is successful

Stop Recording

Description

Stop Recording Group. All RecordComponents in the Group will be deleted.

Inputs

Type	Name	Description
FName (Optional)	Group Name	Optional group name for organizing recordings
bool	Save Recording Data	if false, do not save

Stop Recording RecordComponent

Description

Stop recording actor.
Group don’t stop recording. if you want to stop recording group, use UBloodStainSubsystem::StopRecord

Inputs

Type	Name	Description
URecordComponent	Record Component	Target Record Component
bool	Save Recording Data	if false, do not save

Start Replay From File

Description

Starts a replay directly from a file.
Loads the replay data from disk (if not cached) and spawns replay actors.

Inputs

Type	Name	Description
FString	File Name	File Name
FString	Level Name	Level Name
FBloodStainPlaybackOptions (Optional)	In Playback Options	Optional playback options

Outputs

Type	Name	Description
FGuid	Out Guid	Replaying Group Key
bool	return value	whether the start replay is successful

Start Replay by BloodStain

Description

Starts a replay using a BloodStainActor instance in the world.
A user-friendly wrapper that calls StartReplayFromFile() with info from the actor.

Inputs

Type	Name	Description
ABloodStainActor*	Blood Stain Actor	BloodStain Actor

Outputs

Type	Name	Description
FGuid	Out Guid	Replaying Group Key
bool	return value	whether the start replay is successful

Stop Replay

Description

Forcefully stops an entire replay session identified by its key.
Immediately destroys all actors within the group and removes the session from management from the subsystem’s management.

Inputs

Type	Name	Description
FGuid	Playback Key	Target Playback Key

Stop Replay PlayComponent

Description

This don’t stop All Actors Playback. if you want to stop All of them, use UBloodStainSubsystem::StopReplay

Inputs

Type	Name	Description
AReplayActor*	Ghost Actor	Target Playback ReplayActor

GetPlaybackGroup

Description

Get Playback Group by Guid (Created by StartReplay)

Inputs

Type	Name	Description
FGuid	In Guid	Playback Key

Outputs

Type	Name	Description
FBloodStainPlaybackGroup&	OutBloodStainPlaybackGroup	Replaying Playback Group
bool	return value	Whether the Playback Group is Exist

Is Playing

Description

Whether playback group is Playing

Inputs

Type	Name	Description
FGuid	InPlaybackKey	Playback Key

Outputs

Type	Name	Description
bool	return value	Whether the Playback Group is Replaying

SetRecordingGroupMainActor

Description

Set Main Actor for specify the SpawnPointTransform position
If null, it is set to the middle position of the Actors.

Inputs

Type	Name	Description
AActor*	Target Actor	Group’s Main Actor for Spawn Transform
FName (Optional)	GroupName	Target Group Name

GetDefaultMaterial

Description

Get Current Default Material

Outputs

Type	Name	Description
MaterialInterface*	Return Value	Current Default Material

SetDefaultMaterial

Description

Sets the Default Material for all Meshes within the Actor during playback. If bUseGhostMaterial is true, the Material is applied based on the following priority:

1. Material parameter from PlaybackOption
2. DefaultMaterial

Inputs

Type	Name	Description
MaterialInterface*	In Material	Target Material

SpawnBloodStain

Description

Spawn BloodStain.

Inputs

Type	Name	Description
FString	File Name	Target File Name without extension
FString	Level Name	Target Level Name
FBloodStainPlaybackOptions (Optional)	Playback Options	PlaybackOption

SpawnAllBloodStainInLevel

Description

Spawn All BloodStain In Level.
Internally, it resets the cached Headers and reloads the Headers within the Level to update the Cache.

Inputs

Type	Name	Description
FBloodStainPlaybackOptions (Optional)	Playback Options	PlaybackOption

AddToPendingGroup

Description

Add Actor to Record Pending Group

Inputs

Type	Name	Description
AActor*	Actor	Target Actor
FName (Optional)	GroupName	Pending Group Name

AddToPendingGroupWithActors

Description

Add Actors to Record Pending Group

Inputs

Type	Name	Description
TArray<AActor*>	Actors	Target Actors
FName (Optional)	GroupName	Pending Group Name

RemoveFromPendingGroup

Description

Remove Actor from Record Pending Group

Inputs

Type	Name	Description
AActor*	Actor	Target Actor
FName (Optional)	GroupName	Pending Group Name

RemoveFromPendingGroupWithActors

Description

Remove Actors from Record Pending Group

Inputs

Type	Name	Description
TArray<AActor*>	Actors	Target Actors
FName (Optional)	GroupName	Pending Group Name

StartRecordingWithPendingGroup

Description

Start Record With Record Pending Group
Call internally UBloodStainSubSystem::StartRecording()

Inputs

Type	Name	Description
FBloodStainRecordOptions (Optional)	Record Options	Record Option

SetPendingGroupMainActor

Description

Set Pending Group’s Main Actor for specify the SpawnPointTransform position
If null, it is set to the middle position of the Actors.
If Group is already Recording and mainActor is already exist, override main actor.

Inputs

Type	Name	Description
AActor*	Target Actor	Group’s Main Actor for Spawn Transform
FName (Optional)	GroupName	Target Group Name

SetPendingActorUserData

Description

Set the pending actor’s user data. The set data will be saved in the file’s header data.
If Actor is not Added to Pending Group, dose not work.

Inputs

Type	Name	Description
FName (Optional)	GroupName	Target Group Name
AActor*	Target Actor	Target Actor
FInstanced	InInstancedStruct	Information to be included in the file header as the actor’s user data.

Outputs

Type	Name	Description