p.ChaosSolverEnableJointConstraints

p.ChaosSolverEnableJointConstraints

#Overview

name: p.ChaosSolverEnableJointConstraints

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

It is referenced in 5 C++ source files.

#Summary

#Usage in the C++ source code

The purpose of p.ChaosSolverEnableJointConstraints is to control the enablement of joint constraints defined within the Physics Asset Editor in the Chaos physics system of Unreal Engine 5.

This setting variable is primarily used in the Chaos physics system, which is part of Unreal Engine’s physics module. It specifically affects the functionality related to joint constraints in physics simulations.

The value of this variable is set using an FAutoConsoleVariableRef, which means it can be modified at runtime through console commands or configuration files. Its default value is set to true.

The associated variable bEnableChaosJointConstraints directly interacts with p.ChaosSolverEnableJointConstraints. They share the same value, and bEnableChaosJointConstraints is used in the actual code logic to determine whether joint constraints should be enabled.

Developers must be aware that this variable affects the creation and behavior of physics constraints in the Chaos system. When disabled, it may prevent the creation of joint constraints, potentially altering the physics simulation results.

Best practices when using this variable include:

  1. Ensuring it’s enabled when joint constraints are crucial for the game’s physics simulation.
  2. Consider performance implications when enabling or disabling this feature, as it may affect physics calculations.
  3. Use it in conjunction with other Chaos physics settings for fine-tuning the physics behavior.

Regarding the associated variable bEnableChaosJointConstraints:

The purpose of bEnableChaosJointConstraints is to serve as a runtime flag that controls the enablement of joint constraints in the Chaos physics system.

This variable is used directly in the PhysicsCore module of Unreal Engine, specifically in the ChaosEngineInterface.

The value of bEnableChaosJointConstraints is set through the p.ChaosSolverEnableJointConstraints console variable.

It interacts directly with the physics constraint creation and release functions in the Chaos system. When false, these functions may skip the creation or manipulation of joint constraints.

Developers should be aware that this flag directly affects the behavior of physics simulations. Disabling it may lead to unexpected physics behavior if the game relies on joint constraints.

Best practices for using bEnableChaosJointConstraints include:

  1. Use it as a quick way to toggle joint constraint functionality for debugging or performance testing.
  2. Ensure that disabling this flag doesn’t break critical game mechanics that rely on joint constraints.
  3. Consider exposing this setting to end-users only if there’s a specific need for them to control physics fidelity.

#References in C++ code

#Callsites

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

#Loc: <Workspace>/Engine/Source/Runtime/PhysicsCore/Private/ChaosEngineInterface.cpp:39

Scope: file

Source code excerpt:


bool bEnableChaosJointConstraints = true;
FAutoConsoleVariableRef CVarEnableChaosJointConstraints(TEXT("p.ChaosSolverEnableJointConstraints"), bEnableChaosJointConstraints, TEXT("Enable Joint Constraints defined within the Physics Asset Editor"));

bool bEnableChaosCollisionManager = true;
FAutoConsoleVariableRef CVarEnableChaosCollisionManager(TEXT("p.Chaos.Collision.EnableCollisionManager"), bEnableChaosCollisionManager, TEXT("Enable Chaos's Collision Manager for ignoring collisions between rigid bodies. [def:1]"));

bool FPhysicsConstraintReference_Chaos::IsValid() const
{

#Associated Variable and Callsites

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

#Loc: <Workspace>/Engine/Source/Runtime/PhysicsCore/Private/ChaosEngineInterface.cpp:38

Scope: file

Source code excerpt:

}

bool bEnableChaosJointConstraints = true;
FAutoConsoleVariableRef CVarEnableChaosJointConstraints(TEXT("p.ChaosSolverEnableJointConstraints"), bEnableChaosJointConstraints, TEXT("Enable Joint Constraints defined within the Physics Asset Editor"));

bool bEnableChaosCollisionManager = true;
FAutoConsoleVariableRef CVarEnableChaosCollisionManager(TEXT("p.Chaos.Collision.EnableCollisionManager"), bEnableChaosCollisionManager, TEXT("Enable Chaos's Collision Manager for ignoring collisions between rigid bodies. [def:1]"));

bool FPhysicsConstraintReference_Chaos::IsValid() const
{

#Loc: <Workspace>/Engine/Source/Runtime/PhysicsCore/Private/ChaosEngineInterface.cpp:1293

Scope (from outer to inner):

file
function     FPhysicsConstraintHandle FChaosEngineInterface::CreateConstraint

Source code excerpt:

	FPhysicsConstraintHandle ConstraintRef;

	if (bEnableChaosJointConstraints)
	{
		Chaos::FPhysicsSolver* Solver1 = Chaos::FPhysicsObjectInterface::GetSolver({ &Body1, 1 });
		Chaos::FPhysicsSolver* Solver2 = Chaos::FPhysicsObjectInterface::GetSolver({ &Body2, 1 });

		if (Body1 && Body2 && Solver1 && Solver2)
		{

#Loc: <Workspace>/Engine/Source/Runtime/PhysicsCore/Private/ChaosEngineInterface.cpp:1392

Scope (from outer to inner):

file
function     FPhysicsConstraintHandle FChaosEngineInterface::CreateSuspension

Source code excerpt:

	FPhysicsConstraintHandle ConstraintRef;

	if (bEnableChaosJointConstraints)
	{
		if (Body)
		{
			Chaos::FPhysicsSolver* Solver = Chaos::FPhysicsObjectInterface::GetSolver({ &Body, 1 });

			if (Solver)

#Loc: <Workspace>/Engine/Source/Runtime/PhysicsCore/Private/ChaosEngineInterface.cpp:1430

Scope (from outer to inner):

file
function     void FChaosEngineInterface::ReleaseConstraint

Source code excerpt:

{
	using namespace Chaos;
	if (bEnableChaosJointConstraints)
	{
		if (InConstraintRef.IsValid() && InConstraintRef.Constraint->IsType(Chaos::EConstraintType::JointConstraintType))
		{
			if (FJointConstraint* Constraint = static_cast<FJointConstraint*>(InConstraintRef.Constraint))
			{
				if (FJointConstraintPhysicsProxy* Proxy = Constraint->GetProxy<FJointConstraintPhysicsProxy>())