p.Chaos.ImmPhys.Joint.SwingTwistAngleTolerance
p.Chaos.ImmPhys.Joint.SwingTwistAngleTolerance
#Overview
name: p.Chaos.ImmPhys.Joint.SwingTwistAngleTolerance
This variable is created as a Console Variable (cvar).
- type:
Var - help:
SwingTwistAngleTolerance.
It is referenced in 4 C++ source files.
#Summary
#Usage in the C++ source code
The purpose of p.Chaos.ImmPhys.Joint.SwingTwistAngleTolerance is to set the tolerance for swing and twist angles in joint calculations within the Chaos physics engine’s immediate physics simulation.
This setting variable is primarily used by the Chaos physics engine subsystem, specifically within the immediate physics simulation module. It’s part of the joint solver settings in the physics engine.
The value of this variable is set through an FAutoConsoleVariableRef, which means it can be modified at runtime through console commands. It’s initially set to 1.0e-6f (a very small value) in the source code.
The associated variable ChaosImmediate_Joint_SwingTwistAngleTolerance directly interacts with p.Chaos.ImmPhys.Joint.SwingTwistAngleTolerance. They share the same value and are used interchangeably in the code.
Developers must be aware that this variable affects the precision of joint calculations in the physics simulation. A smaller value will result in more precise calculations but may increase computational cost.
Best practices when using this variable include:
- Only modify it if you understand the implications on physics simulation accuracy and performance.
- Test thoroughly after any changes, as it can affect the behavior of all jointed objects in the simulation.
- Consider the balance between simulation accuracy and performance when adjusting this value.
Regarding the associated variable ChaosImmediate_Joint_SwingTwistAngleTolerance:
- Its purpose is the same as p.Chaos.ImmPhys.Joint.SwingTwistAngleTolerance, serving as the internal representation within the engine code.
- It’s used directly in the FSimulation::Simulate function to set the SwingTwistAngleTolerance in the JointsSettings.
- Its value is set at file scope and can be modified through the console variable.
- It interacts with other joint-related variables in the same context, such as PositionTolerance and AngleTolerance.
- Developers should treat it as they would the console variable, understanding that changes will directly affect the physics simulation.
- Best practices include using the console variable for runtime adjustments and only modifying the source code value if a different default is needed for all instances of the engine.
#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:112
Scope: file
Source code excerpt:
Chaos::FRealSingle ChaosImmediate_Joint_MinParentMassRatio = 0.2f;
Chaos::FRealSingle ChaosImmediate_Joint_MaxInertiaRatio = 5.0f;
FAutoConsoleVariableRef CVarChaosImmPhysJointSwingTwistAngleTolerance(TEXT("p.Chaos.ImmPhys.Joint.SwingTwistAngleTolerance"), ChaosImmediate_Joint_SwingTwistAngleTolerance, TEXT("SwingTwistAngleTolerance."));
FAutoConsoleVariableRef CVarChaosImmPhysJointPositionTolerance(TEXT("p.Chaos.ImmPhys.Joint.PositionTolerance"), ChaosImmediate_Joint_PositionTolerance, TEXT("PositionTolerance."));
FAutoConsoleVariableRef CVarChaosImmPhysJointAngleTolerance(TEXT("p.Chaos.ImmPhys.Joint.AngleTolerance"), ChaosImmediate_Joint_AngleTolerance, TEXT("AngleTolerance."));
FAutoConsoleVariableRef CVarChaosImmPhysJointNumShockPropagationIterations(TEXT("p.Chaos.ImmPhys.Joint.NumShockPropagationIterations"), ChaosImmediate_Joint_NumShockPropagationIterations, TEXT("How many iterations to run shock propagation for"));
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."));
#Associated Variable and Callsites
This variable is associated with another variable named ChaosImmediate_Joint_SwingTwistAngleTolerance. They share the same value. See the following C++ source code.
#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/PhysicsEngine/ImmediatePhysics/ImmediatePhysicsChaos/ImmediatePhysicsSimulation_Chaos.cpp:88
Scope: file
Source code excerpt:
FAutoConsoleVariableRef CVarChaosImmPhysCollisionUseManifolds(TEXT("p.Chaos.ImmPhys.Collision.UseManifolds"), ChaosImmediate_Collision_UseManifolds, TEXT("[Legacy Solver] Enable/Disable use of manifoldes in collision."));
Chaos::FRealSingle ChaosImmediate_Joint_SwingTwistAngleTolerance = 1.0e-6f;
Chaos::FRealSingle ChaosImmediate_Joint_PositionTolerance = 0.025f;
Chaos::FRealSingle ChaosImmediate_Joint_AngleTolerance = 0.001f;
int32 ChaosImmediate_Joint_NumShockPropagationIterations = -1;
int32 ChaosImmediate_Joint_SolvePositionLast = 1;
int32 ChaosImmediate_Joint_UsePositionBasedDrives = 1;
int32 ChaosImmediate_Joint_EnableTwistLimits = 1;
#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/PhysicsEngine/ImmediatePhysics/ImmediatePhysicsChaos/ImmediatePhysicsSimulation_Chaos.cpp:112
Scope: file
Source code excerpt:
Chaos::FRealSingle ChaosImmediate_Joint_MinParentMassRatio = 0.2f;
Chaos::FRealSingle ChaosImmediate_Joint_MaxInertiaRatio = 5.0f;
FAutoConsoleVariableRef CVarChaosImmPhysJointSwingTwistAngleTolerance(TEXT("p.Chaos.ImmPhys.Joint.SwingTwistAngleTolerance"), ChaosImmediate_Joint_SwingTwistAngleTolerance, TEXT("SwingTwistAngleTolerance."));
FAutoConsoleVariableRef CVarChaosImmPhysJointPositionTolerance(TEXT("p.Chaos.ImmPhys.Joint.PositionTolerance"), ChaosImmediate_Joint_PositionTolerance, TEXT("PositionTolerance."));
FAutoConsoleVariableRef CVarChaosImmPhysJointAngleTolerance(TEXT("p.Chaos.ImmPhys.Joint.AngleTolerance"), ChaosImmediate_Joint_AngleTolerance, TEXT("AngleTolerance."));
FAutoConsoleVariableRef CVarChaosImmPhysJointNumShockPropagationIterations(TEXT("p.Chaos.ImmPhys.Joint.NumShockPropagationIterations"), ChaosImmediate_Joint_NumShockPropagationIterations, TEXT("How many iterations to run shock propagation for"));
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."));
#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/PhysicsEngine/ImmediatePhysics/ImmediatePhysicsChaos/ImmediatePhysicsSimulation_Chaos.cpp:870
Scope (from outer to inner):
file
namespace ImmediatePhysics_Chaos
function void FSimulation::Simulate
Source code excerpt:
FPBDJointSolverSettings JointsSettings = Implementation->Joints.GetSettings();
JointsSettings.SwingTwistAngleTolerance = ChaosImmediate_Joint_SwingTwistAngleTolerance;
JointsSettings.PositionTolerance = ChaosImmediate_Joint_PositionTolerance;
JointsSettings.AngleTolerance = ChaosImmediate_Joint_AngleTolerance;
JointsSettings.MinParentMassRatio = ChaosImmediate_Joint_MinParentMassRatio;
JointsSettings.MaxInertiaRatio = ChaosImmediate_Joint_MaxInertiaRatio;
JointsSettings.bSolvePositionLast = ChaosImmediate_Joint_SolvePositionLast != 0;
JointsSettings.bUsePositionBasedDrives = ChaosImmediate_Joint_UsePositionBasedDrives != 0;