p.Chaos.ImmPhys.Joint.EnableTwistLimits
p.Chaos.ImmPhys.Joint.EnableTwistLimits
#Overview
name: p.Chaos.ImmPhys.Joint.EnableTwistLimits
This variable is created as a Console Variable (cvar).
- type:
Var - help:
EnableTwistLimits.
It is referenced in 4 C++ source files.
#Summary
#Usage in the C++ source code
The purpose of p.Chaos.ImmPhys.Joint.EnableTwistLimits is to enable or disable twist limits for joints in the Chaos Immediate Physics simulation system of Unreal Engine 5.
This setting variable is primarily used in the physics engine subsystem, specifically in the Chaos Immediate Physics module. It’s part of the joint constraint system that controls the movement and limitations of connected rigid bodies.
The value of this variable is set through the Unreal Engine console variable system. It’s defined as an FAutoConsoleVariableRef, which allows it to be modified at runtime through console commands or configuration files.
The associated variable ChaosImmediate_Joint_EnableTwistLimits interacts directly with p.Chaos.ImmPhys.Joint.EnableTwistLimits. They share the same value, with ChaosImmediate_Joint_EnableTwistLimits being the actual variable used in the simulation code.
Developers should be aware that this variable is a boolean flag (represented as an int32 where 0 is false and non-zero is true). When enabled, it allows the physics simulation to apply twist limits to joints, which can be crucial for realistic movement in certain scenarios.
Best practices when using this variable include:
- Only disable twist limits if you have a specific reason to do so, as they often contribute to more realistic joint behavior.
- Consider the performance implications of enabling or disabling twist limits, especially in scenarios with many joints.
- Use in conjunction with other joint-related settings for fine-tuned control over joint behavior.
Regarding the associated variable ChaosImmediate_Joint_EnableTwistLimits:
- Its purpose is to store the runtime value of the twist limits enable flag.
- It’s used directly in the simulation code to determine whether twist limits should be applied.
- Its value is set by the console variable system and can be changed at runtime.
- It interacts with the JointsSettings structure in the Simulate function, directly affecting the physics simulation behavior.
- Developers should be aware that changing this variable will immediately affect all joints in the simulation.
- Best practice is to modify this variable through the console variable system rather than directly, to ensure consistency with the engine’s configuration system.
#References in C++ code
#Callsites
This variable is referenced in the following C++ source code:
#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/PhysicsEngine/ImmediatePhysics/ImmediatePhysicsChaos/ImmediatePhysicsSimulation_Chaos.cpp:118
Scope: file
Source code excerpt:
FAutoConsoleVariableRef CVarChaosImmPhysJointSolvePositionLast(TEXT("p.Chaos.ImmPhys.Joint.SolvePositionLast"), ChaosImmediate_Joint_SolvePositionLast, TEXT("Should we solve joints in position-then-rotation order (false) rotation-then-position order (true, default)"));
FAutoConsoleVariableRef CVarChaosImmPhysJointUsePBDVelocityDrives(TEXT("p.Chaos.ImmPhys.Joint.UsePBDDrives"), ChaosImmediate_Joint_UsePositionBasedDrives, TEXT("Whether to solve drives in the position or velocity phase of the solver (default true)"));
FAutoConsoleVariableRef CVarChaosImmPhysJointEnableTwistLimits(TEXT("p.Chaos.ImmPhys.Joint.EnableTwistLimits"), ChaosImmediate_Joint_EnableTwistLimits, TEXT("EnableTwistLimits."));
FAutoConsoleVariableRef CVarChaosImmPhysJointEnableSwingLimits(TEXT("p.Chaos.ImmPhys.Joint.EnableSwingLimits"), ChaosImmediate_Joint_EnableSwingLimits, TEXT("EnableSwingLimits."));
FAutoConsoleVariableRef CVarChaosImmPhysJointEnableDrives(TEXT("p.Chaos.ImmPhys.Joint.EnableDrives"), ChaosImmediate_Joint_EnableDrives, TEXT("EnableDrives."));
FAutoConsoleVariableRef CVarChaosImmPhysJointLinearProjection(TEXT("p.Chaos.ImmPhys.Joint.LinearProjection"), ChaosImmediate_Joint_LinearProjection, TEXT("6Dof joint projection amount override (if >= 0)."));
FAutoConsoleVariableRef CVarChaosImmPhysJointAngularProjection(TEXT("p.Chaos.ImmPhys.Joint.AngularProjection"), ChaosImmediate_Joint_AngularProjection, TEXT("6Dof joint projection amount override (if >= 0)."));
FAutoConsoleVariableRef CVarChaosImmPhysJointShockPropagation(TEXT("p.Chaos.ImmPhys.Joint.ShockPropagation"), ChaosImmediate_Joint_ShockPropagation, TEXT("6Dof joint shock propagation override (if >= 0)."));
FAutoConsoleVariableRef CVarChaosImmPhysJointStiffness(TEXT("p.Chaos.ImmPhys.Joint.Stiffness"), ChaosImmediate_Joint_Stiffness, TEXT("6Dof joint stiffness override (if > 0)."));
#Associated Variable and Callsites
This variable is associated with another variable named ChaosImmediate_Joint_EnableTwistLimits. They share the same value. See the following C++ source code.
#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/PhysicsEngine/ImmediatePhysics/ImmediatePhysicsChaos/ImmediatePhysicsSimulation_Chaos.cpp:94
Scope: file
Source code excerpt:
int32 ChaosImmediate_Joint_SolvePositionLast = 1;
int32 ChaosImmediate_Joint_UsePositionBasedDrives = 1;
int32 ChaosImmediate_Joint_EnableTwistLimits = 1;
int32 ChaosImmediate_Joint_EnableSwingLimits = 1;
int32 ChaosImmediate_Joint_EnableDrives = 1;
Chaos::FRealSingle ChaosImmediate_Joint_LinearProjection = -1.0f;
Chaos::FRealSingle ChaosImmediate_Joint_AngularProjection = -1.0f;
Chaos::FRealSingle ChaosImmediate_Joint_ShockPropagation = -1.0f;
Chaos::FRealSingle ChaosImmediate_Joint_Stiffness = -1.0f;
#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/PhysicsEngine/ImmediatePhysics/ImmediatePhysicsChaos/ImmediatePhysicsSimulation_Chaos.cpp:118
Scope: file
Source code excerpt:
FAutoConsoleVariableRef CVarChaosImmPhysJointSolvePositionLast(TEXT("p.Chaos.ImmPhys.Joint.SolvePositionLast"), ChaosImmediate_Joint_SolvePositionLast, TEXT("Should we solve joints in position-then-rotation order (false) rotation-then-position order (true, default)"));
FAutoConsoleVariableRef CVarChaosImmPhysJointUsePBDVelocityDrives(TEXT("p.Chaos.ImmPhys.Joint.UsePBDDrives"), ChaosImmediate_Joint_UsePositionBasedDrives, TEXT("Whether to solve drives in the position or velocity phase of the solver (default true)"));
FAutoConsoleVariableRef CVarChaosImmPhysJointEnableTwistLimits(TEXT("p.Chaos.ImmPhys.Joint.EnableTwistLimits"), ChaosImmediate_Joint_EnableTwistLimits, TEXT("EnableTwistLimits."));
FAutoConsoleVariableRef CVarChaosImmPhysJointEnableSwingLimits(TEXT("p.Chaos.ImmPhys.Joint.EnableSwingLimits"), ChaosImmediate_Joint_EnableSwingLimits, TEXT("EnableSwingLimits."));
FAutoConsoleVariableRef CVarChaosImmPhysJointEnableDrives(TEXT("p.Chaos.ImmPhys.Joint.EnableDrives"), ChaosImmediate_Joint_EnableDrives, TEXT("EnableDrives."));
FAutoConsoleVariableRef CVarChaosImmPhysJointLinearProjection(TEXT("p.Chaos.ImmPhys.Joint.LinearProjection"), ChaosImmediate_Joint_LinearProjection, TEXT("6Dof joint projection amount override (if >= 0)."));
FAutoConsoleVariableRef CVarChaosImmPhysJointAngularProjection(TEXT("p.Chaos.ImmPhys.Joint.AngularProjection"), ChaosImmediate_Joint_AngularProjection, TEXT("6Dof joint projection amount override (if >= 0)."));
FAutoConsoleVariableRef CVarChaosImmPhysJointShockPropagation(TEXT("p.Chaos.ImmPhys.Joint.ShockPropagation"), ChaosImmediate_Joint_ShockPropagation, TEXT("6Dof joint shock propagation override (if >= 0)."));
FAutoConsoleVariableRef CVarChaosImmPhysJointStiffness(TEXT("p.Chaos.ImmPhys.Joint.Stiffness"), ChaosImmediate_Joint_Stiffness, TEXT("6Dof joint stiffness override (if > 0)."));
#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/PhysicsEngine/ImmediatePhysics/ImmediatePhysicsChaos/ImmediatePhysicsSimulation_Chaos.cpp:877
Scope (from outer to inner):
file
namespace ImmediatePhysics_Chaos
function void FSimulation::Simulate
Source code excerpt:
JointsSettings.bSolvePositionLast = ChaosImmediate_Joint_SolvePositionLast != 0;
JointsSettings.bUsePositionBasedDrives = ChaosImmediate_Joint_UsePositionBasedDrives != 0;
JointsSettings.bEnableTwistLimits = ChaosImmediate_Joint_EnableTwistLimits != 0;
JointsSettings.bEnableSwingLimits = ChaosImmediate_Joint_EnableSwingLimits != 0;
JointsSettings.bEnableDrives = ChaosImmediate_Joint_EnableDrives != 0;
JointsSettings.LinearStiffnessOverride = ChaosImmediate_Joint_Stiffness;
JointsSettings.TwistStiffnessOverride = ChaosImmediate_Joint_Stiffness;
JointsSettings.SwingStiffnessOverride = ChaosImmediate_Joint_Stiffness;
JointsSettings.LinearProjectionOverride = ChaosImmediate_Joint_LinearProjection;