bSimulateAnimPhysicsAfterReset
bSimulateAnimPhysicsAfterReset
#Overview
name: bSimulateAnimPhysicsAfterReset
The value of this variable can be defined or overridden in .ini config files. 1 .ini config file referencing this setting variable.
It is referenced in 10 C++ source files.
#Summary
#Usage in the C++ source code
The purpose of bSimulateAnimPhysicsAfterReset is to control whether animation physics nodes should be simulated in the tick where they are reset. This setting is primarily used in the physics simulation system of Unreal Engine, specifically for animation-driven physics.
This variable is mainly used in the Unreal Engine’s animation and physics systems, particularly in the RigidBody animation nodes. It’s referenced in both the experimental PhysicsControl plugin and the core AnimGraphRuntime module.
The value of this variable is set in the UPhysicsSettings class, which is part of the Engine’s physics configuration. It can be modified through the project settings in the Unreal Editor.
bSimulateAnimPhysicsAfterReset interacts closely with other physics-related variables such as AnimPhysicsMinDeltaTime and ResetSimulatedTeleportType. It’s used in conjunction with these variables to determine whether a physics simulation tick is needed after a reset.
Developers should be aware that enabling this option may lead to an additional physics simulation step immediately after a reset, which could impact performance or cause unexpected behavior in certain scenarios. It’s important to consider the trade-offs between accuracy and performance when using this setting.
Best practices for using this variable include:
- Only enable it if you need precise physics behavior immediately after resets.
- Monitor performance impact, especially in scenes with many physics-driven animations.
- Test thoroughly to ensure it doesn’t introduce unwanted jitter or instability in your animations.
- Consider the interaction with other physics settings, particularly AnimPhysicsMinDeltaTime and ResetSimulatedTeleportType.
- Use it in conjunction with proper physics asset setup and tuning for optimal results.
#Setting Variables
#References In INI files
Location: <Workspace>/Projects/Lyra/Config/DefaultEngine.ini:335, section: [/Script/Engine.PhysicsSettings]
- INI Section:
/Script/Engine.PhysicsSettings - Raw value:
False - Is Array:
False
#References in C++ code
#Callsites
This variable is referenced in the following C++ source code:
#Loc: <Workspace>/Engine/Plugins/Experimental/PhysicsControl/Source/PhysicsControl/Private/AnimNode_RigidBodyWithControl.cpp:157
Scope (from outer to inner):
file
function FAnimNode_RigidBodyWithControl::FAnimNode_RigidBodyWithControl
Source code excerpt:
, AccumulatedDeltaTime(0.0f)
, AnimPhysicsMinDeltaTime(0.0f)
, bSimulateAnimPhysicsAfterReset(false)
, SkelMeshCompWeakPtr()
, PhysicsSimulation(nullptr)
, SolverSettings()
, SolverIterations()
, SimulationTask()
, OutputBoneData()
#Loc: <Workspace>/Engine/Plugins/Experimental/PhysicsControl/Source/PhysicsControl/Private/AnimNode_RigidBodyWithControl.cpp:682
Scope (from outer to inner):
file
function void FAnimNode_RigidBodyWithControl::EvaluateSkeletalControl_AnyThread
Source code excerpt:
// Only need to tick physics if we didn't reset and we have some time to simulate
const bool bNeedsSimulationTick =
((bSimulateAnimPhysicsAfterReset || (ResetSimulatedTeleportType != ETeleportType::ResetPhysics)) &&
DeltaSeconds > AnimPhysicsMinDeltaTime);
if (bNeedsSimulationTick)
{
// Update the pose data
{
SCOPE_CYCLE_COUNTER(STAT_RigidBodyNodeWithControl_PoseUpdate);
#Loc: <Workspace>/Engine/Plugins/Experimental/PhysicsControl/Source/PhysicsControl/Private/AnimNode_RigidBodyWithControl.cpp:985
Scope (from outer to inner):
file
function void FAnimNode_RigidBodyWithControl::InitPhysics
Source code excerpt:
{
AnimPhysicsMinDeltaTime = Settings->AnimPhysicsMinDeltaTime;
bSimulateAnimPhysicsAfterReset = Settings->bSimulateAnimPhysicsAfterReset;
}
else
{
AnimPhysicsMinDeltaTime = 0.f;
bSimulateAnimPhysicsAfterReset = false;
}
bEnabled = PhysicsAssetToUse && SkeletalMeshComp->GetAllowRigidBodyAnimNode() && CVarEnableRigidBodyNodeWithControl.GetValueOnAnyThread() != 0;
if(bEnabled)
{
PhysicsSimulation = new ImmediatePhysics::FSimulation();
#Loc: <Workspace>/Engine/Plugins/Experimental/PhysicsControl/Source/PhysicsControl/Public/AnimNode_RigidBodyWithControl.h:513
Scope: file
Source code excerpt:
float AccumulatedDeltaTime;
float AnimPhysicsMinDeltaTime;
bool bSimulateAnimPhysicsAfterReset;
/** This should only be used for removing the delegate during termination. Do NOT use this for any per frame work */
TWeakObjectPtr<USkeletalMeshComponent> SkelMeshCompWeakPtr;
ImmediatePhysics::FSimulation* PhysicsSimulation;
FPhysicsAssetSolverSettings SolverSettings;
FSolverIterations SolverIterations; // to be deprecated
#Loc: <Workspace>/Engine/Source/Runtime/AnimGraphRuntime/Private/BoneControllers/AnimNode_RigidBody.cpp:198
Scope (from outer to inner):
file
function FAnimNode_RigidBody::FAnimNode_RigidBody
Source code excerpt:
, AccumulatedDeltaTime(0.0f)
, AnimPhysicsMinDeltaTime(0.0f)
, bSimulateAnimPhysicsAfterReset(false)
, SkelMeshCompWeakPtr()
, PhysicsSimulation(nullptr)
, SolverSettings()
, SolverIterations()
, SimulationTask()
, OutputBoneData()
#Loc: <Workspace>/Engine/Source/Runtime/AnimGraphRuntime/Private/BoneControllers/AnimNode_RigidBody.cpp:704
Scope (from outer to inner):
file
function void FAnimNode_RigidBody::EvaluateSkeletalControl_AnyThread
Source code excerpt:
// Only need to tick physics if we didn't reset and we have some time to simulate
const bool bNeedsSimulationTick = ((bSimulateAnimPhysicsAfterReset || (ResetSimulatedTeleportType != ETeleportType::ResetPhysics)) && DeltaSeconds > AnimPhysicsMinDeltaTime);
if (bNeedsSimulationTick)
{
// Transfer bone velocities previously captured.
if (bTransferBoneVelocities && (CapturedBoneVelocityPose.GetPose().GetNumBones() > 0))
{
for (const FOutputBoneData& OutputData : OutputBoneData)
#Loc: <Workspace>/Engine/Source/Runtime/AnimGraphRuntime/Private/BoneControllers/AnimNode_RigidBody.cpp:1051
Scope (from outer to inner):
file
function void FAnimNode_RigidBody::InitPhysics
Source code excerpt:
{
AnimPhysicsMinDeltaTime = Settings->AnimPhysicsMinDeltaTime;
bSimulateAnimPhysicsAfterReset = Settings->bSimulateAnimPhysicsAfterReset;
}
else
{
AnimPhysicsMinDeltaTime = 0.f;
bSimulateAnimPhysicsAfterReset = false;
}
bEnabled = (UsePhysicsAsset && bEnableRigidBodyNode && SkeletalMeshComp->GetAllowRigidBodyAnimNode());
if(bEnabled)
{
SCOPE_CYCLE_COUNTER(STAT_RigidBodyNodeInitTime_SetupSimulation);
#Loc: <Workspace>/Engine/Source/Runtime/AnimGraphRuntime/Public/BoneControllers/AnimNode_RigidBody.h:403
Scope: file
Source code excerpt:
float AccumulatedDeltaTime;
float AnimPhysicsMinDeltaTime;
bool bSimulateAnimPhysicsAfterReset;
/** This should only be used for removing the delegate during termination. Do NOT use this for any per frame work */
TWeakObjectPtr<USkeletalMeshComponent> SkelMeshCompWeakPtr;
ImmediatePhysics::FSimulation* PhysicsSimulation;
FPhysicsAssetSolverSettings SolverSettings;
FSolverIterations SolverIterations; // to be deprecated
#Loc: <Workspace>/Engine/Source/Runtime/Engine/Classes/PhysicsEngine/PhysicsSettings.h:193
Scope (from outer to inner):
file
class class UPhysicsSettings : public UPhysicsSettingsCore
Source code excerpt:
/** Whether to simulate anim physics nodes in the tick where they're reset. */
UPROPERTY(config, EditAnywhere, Category = Simulation)
bool bSimulateAnimPhysicsAfterReset;
/** Min Physics Delta Time; the simulation will not step if the delta time is below this value */
UPROPERTY(config, EditAnywhere, meta = (ClampMin = "0.0", UIMin = "0.0", ClampMax = "0.0001", UIMax = "0.0001"), Category = Framerate)
float MinPhysicsDeltaTime;
/** Max Physics Delta Time to be clamped. */
#Loc: <Workspace>/Engine/Source/Runtime/Engine/Private/PhysicsEngine/PhysicsSettings.cpp:17
Scope (from outer to inner):
file
function UPhysicsSettings::UPhysicsSettings
Source code excerpt:
, bDisableActiveActors(false)
, AnimPhysicsMinDeltaTime(0.f)
, bSimulateAnimPhysicsAfterReset(false)
, MinPhysicsDeltaTime(UE_SMALL_NUMBER)
, MaxPhysicsDeltaTime(1.f / 30.f)
, bSubstepping(false)
, bTickPhysicsAsync(false)
, AsyncFixedTimeStepSize(1.f / 30.f)
, MaxSubstepDeltaTime(1.f / 60.f)