a.Streaming.SpoofFailedChunkLoad

a.Streaming.SpoofFailedChunkLoad

#Overview

name: a.Streaming.SpoofFailedChunkLoad

This variable is created as a Console Variable (cvar).

• type: Var
• help: Forces failing to load streamed animation chunks.\n0: Not Enabled, 1: Enabled

It is referenced in 3 C++ source files.

#Summary

#Usage in the C++ source code

The purpose of a.Streaming.SpoofFailedChunkLoad is to simulate failed loading of streamed animation chunks in Unreal Engine 5. This setting variable is primarily used for testing and debugging purposes within the animation streaming system.

• The Unreal Engine Animation Streaming subsystem relies on this setting variable, as evidenced by its usage in the AnimationStreaming.cpp file.

• The value of this variable is set through a console variable (CVar) using the FAutoConsoleVariableRef mechanism. It can be modified at runtime through the console or configuration files.

• This variable interacts directly with the associated variable SpoofFailedAnimationChunkLoad. They share the same value and purpose.

• Developers must be aware that enabling this variable (setting it to 1) will force all attempts to load streamed animation chunks to fail. This can significantly impact the performance and functionality of animations in the game or application.

• Best practices when using this variable include:

  1. Only enable it for testing and debugging purposes.
  2. Ensure it’s disabled (set to 0) in production builds.
  3. Use it in conjunction with other debugging tools to isolate and identify issues related to animation streaming.
  4. Document its usage clearly in the project to prevent unintended consequences.

Regarding the associated variable SpoofFailedAnimationChunkLoad:

The purpose of SpoofFailedAnimationChunkLoad is to serve as the actual storage for the a.Streaming.SpoofFailedChunkLoad console variable. It’s an integer variable that directly controls the behavior of the animation streaming system.

• This variable is used within the GetLoadedChunk function of the FAnimationStreamingManager class to determine whether to simulate a failed chunk load.

• Its value is set through the console variable mechanism and can be modified at runtime.

• When SpoofFailedAnimationChunkLoad is greater than 0, the GetLoadedChunk function will return nullptr, simulating a failed chunk load.

• Developers should be cautious when modifying this variable directly in code, as it’s primarily intended to be controlled through the console variable system.

• Best practices for using SpoofFailedAnimationChunkLoad include:

  1. Avoid modifying it directly in code unless absolutely necessary.
  2. Use the console variable a.Streaming.SpoofFailedChunkLoad for controlling its value.
  3. Reset it to 0 after testing to ensure normal animation streaming behavior.
  4. Consider adding debug logging when this variable is non-zero to track its usage during development.

#References in C++ code

#Callsites

This variable is referenced in the following C++ source code:

#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/Animation/AnimationStreaming.cpp:12

Scope: file

Source code excerpt:

static int32 SpoofFailedAnimationChunkLoad = 0;
FAutoConsoleVariableRef CVarSpoofFailedAnimationChunkLoad(
	TEXT("a.Streaming.SpoofFailedChunkLoad"),
	SpoofFailedAnimationChunkLoad,
	TEXT("Forces failing to load streamed animation chunks.\n")
	TEXT("0: Not Enabled, 1: Enabled"),
	ECVF_Default);

#Associated Variable and Callsites

This variable is associated with another variable named SpoofFailedAnimationChunkLoad. They share the same value. See the following C++ source code.

#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/Animation/AnimationStreaming.cpp:10

Scope: file

Source code excerpt:

#include "HAL/PlatformFile.h"

static int32 SpoofFailedAnimationChunkLoad = 0;
FAutoConsoleVariableRef CVarSpoofFailedAnimationChunkLoad(
	TEXT("a.Streaming.SpoofFailedChunkLoad"),
	SpoofFailedAnimationChunkLoad,
	TEXT("Forces failing to load streamed animation chunks.\n")
	TEXT("0: Not Enabled, 1: Enabled"),
	ECVF_Default);

#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/Animation/AnimationStreaming.cpp:498

Scope (from outer to inner):

file
function     const FCompressedAnimSequence* FAnimationStreamingManager::GetLoadedChunk

Source code excerpt:

{
	// Check for the spoof of failing to load a stream chunk
	if (SpoofFailedAnimationChunkLoad > 0)
	{
		return nullptr;
	}

	// If we fail at getting the critical section here, early out.
	FScopeLock MapLock(&CriticalSection);