godot-module-template/engine/thirdparty/jolt_physics/Jolt/Physics/Constraints/SixDOFConstraint.cpp

901 lines
33 KiB
C++

// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
// SPDX-FileCopyrightText: 2021 Jorrit Rouwe
// SPDX-License-Identifier: MIT
#include <Jolt/Jolt.h>
#include <Jolt/Physics/Constraints/SixDOFConstraint.h>
#include <Jolt/Physics/Body/Body.h>
#include <Jolt/Geometry/Ellipse.h>
#include <Jolt/ObjectStream/TypeDeclarations.h>
#include <Jolt/Core/StreamIn.h>
#include <Jolt/Core/StreamOut.h>
#ifdef JPH_DEBUG_RENDERER
#include <Jolt/Renderer/DebugRenderer.h>
#endif // JPH_DEBUG_RENDERER
JPH_NAMESPACE_BEGIN
JPH_IMPLEMENT_SERIALIZABLE_VIRTUAL(SixDOFConstraintSettings)
{
JPH_ADD_BASE_CLASS(SixDOFConstraintSettings, TwoBodyConstraintSettings)
JPH_ADD_ENUM_ATTRIBUTE(SixDOFConstraintSettings, mSpace)
JPH_ADD_ATTRIBUTE(SixDOFConstraintSettings, mPosition1)
JPH_ADD_ATTRIBUTE(SixDOFConstraintSettings, mAxisX1)
JPH_ADD_ATTRIBUTE(SixDOFConstraintSettings, mAxisY1)
JPH_ADD_ATTRIBUTE(SixDOFConstraintSettings, mPosition2)
JPH_ADD_ATTRIBUTE(SixDOFConstraintSettings, mAxisX2)
JPH_ADD_ATTRIBUTE(SixDOFConstraintSettings, mAxisY2)
JPH_ADD_ATTRIBUTE(SixDOFConstraintSettings, mMaxFriction)
JPH_ADD_ENUM_ATTRIBUTE(SixDOFConstraintSettings, mSwingType)
JPH_ADD_ATTRIBUTE(SixDOFConstraintSettings, mLimitMin)
JPH_ADD_ATTRIBUTE(SixDOFConstraintSettings, mLimitMax)
JPH_ADD_ATTRIBUTE(SixDOFConstraintSettings, mLimitsSpringSettings)
JPH_ADD_ATTRIBUTE(SixDOFConstraintSettings, mMotorSettings)
}
void SixDOFConstraintSettings::SaveBinaryState(StreamOut &inStream) const
{
ConstraintSettings::SaveBinaryState(inStream);
inStream.Write(mSpace);
inStream.Write(mPosition1);
inStream.Write(mAxisX1);
inStream.Write(mAxisY1);
inStream.Write(mPosition2);
inStream.Write(mAxisX2);
inStream.Write(mAxisY2);
inStream.Write(mMaxFriction);
inStream.Write(mSwingType);
inStream.Write(mLimitMin);
inStream.Write(mLimitMax);
for (const SpringSettings &s : mLimitsSpringSettings)
s.SaveBinaryState(inStream);
for (const MotorSettings &m : mMotorSettings)
m.SaveBinaryState(inStream);
}
void SixDOFConstraintSettings::RestoreBinaryState(StreamIn &inStream)
{
ConstraintSettings::RestoreBinaryState(inStream);
inStream.Read(mSpace);
inStream.Read(mPosition1);
inStream.Read(mAxisX1);
inStream.Read(mAxisY1);
inStream.Read(mPosition2);
inStream.Read(mAxisX2);
inStream.Read(mAxisY2);
inStream.Read(mMaxFriction);
inStream.Read(mSwingType);
inStream.Read(mLimitMin);
inStream.Read(mLimitMax);
for (SpringSettings &s : mLimitsSpringSettings)
s.RestoreBinaryState(inStream);
for (MotorSettings &m : mMotorSettings)
m.RestoreBinaryState(inStream);
}
TwoBodyConstraint *SixDOFConstraintSettings::Create(Body &inBody1, Body &inBody2) const
{
return new SixDOFConstraint(inBody1, inBody2, *this);
}
void SixDOFConstraint::UpdateTranslationLimits()
{
// Set to zero if the limits are inversed
for (int i = EAxis::TranslationX; i <= EAxis::TranslationZ; ++i)
if (mLimitMin[i] > mLimitMax[i])
mLimitMin[i] = mLimitMax[i] = 0.0f;
}
void SixDOFConstraint::UpdateRotationLimits()
{
if (mSwingTwistConstraintPart.GetSwingType() == ESwingType::Cone)
{
// Cone swing upper limit needs to be positive
mLimitMax[EAxis::RotationY] = max(0.0f, mLimitMax[EAxis::RotationY]);
mLimitMax[EAxis::RotationZ] = max(0.0f, mLimitMax[EAxis::RotationZ]);
// Cone swing limits only support symmetric ranges
mLimitMin[EAxis::RotationY] = -mLimitMax[EAxis::RotationY];
mLimitMin[EAxis::RotationZ] = -mLimitMax[EAxis::RotationZ];
}
for (int i = EAxis::RotationX; i <= EAxis::RotationZ; ++i)
{
// Clamp to [-PI, PI] range
mLimitMin[i] = Clamp(mLimitMin[i], -JPH_PI, JPH_PI);
mLimitMax[i] = Clamp(mLimitMax[i], -JPH_PI, JPH_PI);
// Set to zero if the limits are inversed
if (mLimitMin[i] > mLimitMax[i])
mLimitMin[i] = mLimitMax[i] = 0.0f;
}
// Pass limits on to constraint part
mSwingTwistConstraintPart.SetLimits(mLimitMin[EAxis::RotationX], mLimitMax[EAxis::RotationX], mLimitMin[EAxis::RotationY], mLimitMax[EAxis::RotationY], mLimitMin[EAxis::RotationZ], mLimitMax[EAxis::RotationZ]);
}
void SixDOFConstraint::UpdateFixedFreeAxis()
{
uint8 old_free_axis = mFreeAxis;
uint8 old_fixed_axis = mFixedAxis;
// Cache which axis are fixed and which ones are free
mFreeAxis = 0;
mFixedAxis = 0;
for (int a = 0; a < EAxis::Num; ++a)
{
float limit = a >= EAxis::RotationX? JPH_PI : FLT_MAX;
if (mLimitMin[a] >= mLimitMax[a])
mFixedAxis |= 1 << a;
else if (mLimitMin[a] <= -limit && mLimitMax[a] >= limit)
mFreeAxis |= 1 << a;
}
// On change we deactivate all constraints to reset warm starting
if (old_free_axis != mFreeAxis || old_fixed_axis != mFixedAxis)
{
for (AxisConstraintPart &c : mTranslationConstraintPart)
c.Deactivate();
mPointConstraintPart.Deactivate();
mSwingTwistConstraintPart.Deactivate();
mRotationConstraintPart.Deactivate();
for (AxisConstraintPart &c : mMotorTranslationConstraintPart)
c.Deactivate();
for (AngleConstraintPart &c : mMotorRotationConstraintPart)
c.Deactivate();
}
}
SixDOFConstraint::SixDOFConstraint(Body &inBody1, Body &inBody2, const SixDOFConstraintSettings &inSettings) :
TwoBodyConstraint(inBody1, inBody2, inSettings)
{
// Override swing type
mSwingTwistConstraintPart.SetSwingType(inSettings.mSwingType);
// Calculate rotation needed to go from constraint space to body1 local space
Vec3 axis_z1 = inSettings.mAxisX1.Cross(inSettings.mAxisY1);
Mat44 c_to_b1(Vec4(inSettings.mAxisX1, 0), Vec4(inSettings.mAxisY1, 0), Vec4(axis_z1, 0), Vec4(0, 0, 0, 1));
mConstraintToBody1 = c_to_b1.GetQuaternion();
// Calculate rotation needed to go from constraint space to body2 local space
Vec3 axis_z2 = inSettings.mAxisX2.Cross(inSettings.mAxisY2);
Mat44 c_to_b2(Vec4(inSettings.mAxisX2, 0), Vec4(inSettings.mAxisY2, 0), Vec4(axis_z2, 0), Vec4(0, 0, 0, 1));
mConstraintToBody2 = c_to_b2.GetQuaternion();
if (inSettings.mSpace == EConstraintSpace::WorldSpace)
{
// If all properties were specified in world space, take them to local space now
mLocalSpacePosition1 = Vec3(inBody1.GetInverseCenterOfMassTransform() * inSettings.mPosition1);
mConstraintToBody1 = inBody1.GetRotation().Conjugated() * mConstraintToBody1;
mLocalSpacePosition2 = Vec3(inBody2.GetInverseCenterOfMassTransform() * inSettings.mPosition2);
mConstraintToBody2 = inBody2.GetRotation().Conjugated() * mConstraintToBody2;
}
else
{
mLocalSpacePosition1 = Vec3(inSettings.mPosition1);
mLocalSpacePosition2 = Vec3(inSettings.mPosition2);
}
// Copy translation and rotation limits
memcpy(mLimitMin, inSettings.mLimitMin, sizeof(mLimitMin));
memcpy(mLimitMax, inSettings.mLimitMax, sizeof(mLimitMax));
memcpy(mLimitsSpringSettings, inSettings.mLimitsSpringSettings, sizeof(mLimitsSpringSettings));
UpdateTranslationLimits();
UpdateRotationLimits();
UpdateFixedFreeAxis();
CacheHasSpringLimits();
// Store friction settings
memcpy(mMaxFriction, inSettings.mMaxFriction, sizeof(mMaxFriction));
// Store motor settings
for (int i = 0; i < EAxis::Num; ++i)
mMotorSettings[i] = inSettings.mMotorSettings[i];
// Cache if motors are active (motors are off initially, but we may have friction)
CacheTranslationMotorActive();
CacheRotationMotorActive();
}
void SixDOFConstraint::NotifyShapeChanged(const BodyID &inBodyID, Vec3Arg inDeltaCOM)
{
if (mBody1->GetID() == inBodyID)
mLocalSpacePosition1 -= inDeltaCOM;
else if (mBody2->GetID() == inBodyID)
mLocalSpacePosition2 -= inDeltaCOM;
}
void SixDOFConstraint::SetTranslationLimits(Vec3Arg inLimitMin, Vec3Arg inLimitMax)
{
mLimitMin[EAxis::TranslationX] = inLimitMin.GetX();
mLimitMin[EAxis::TranslationY] = inLimitMin.GetY();
mLimitMin[EAxis::TranslationZ] = inLimitMin.GetZ();
mLimitMax[EAxis::TranslationX] = inLimitMax.GetX();
mLimitMax[EAxis::TranslationY] = inLimitMax.GetY();
mLimitMax[EAxis::TranslationZ] = inLimitMax.GetZ();
UpdateTranslationLimits();
UpdateFixedFreeAxis();
}
void SixDOFConstraint::SetRotationLimits(Vec3Arg inLimitMin, Vec3Arg inLimitMax)
{
mLimitMin[EAxis::RotationX] = inLimitMin.GetX();
mLimitMin[EAxis::RotationY] = inLimitMin.GetY();
mLimitMin[EAxis::RotationZ] = inLimitMin.GetZ();
mLimitMax[EAxis::RotationX] = inLimitMax.GetX();
mLimitMax[EAxis::RotationY] = inLimitMax.GetY();
mLimitMax[EAxis::RotationZ] = inLimitMax.GetZ();
UpdateRotationLimits();
UpdateFixedFreeAxis();
}
void SixDOFConstraint::SetMaxFriction(EAxis inAxis, float inFriction)
{
mMaxFriction[inAxis] = inFriction;
if (inAxis >= EAxis::TranslationX && inAxis <= EAxis::TranslationZ)
CacheTranslationMotorActive();
else
CacheRotationMotorActive();
}
void SixDOFConstraint::GetPositionConstraintProperties(Vec3 &outR1PlusU, Vec3 &outR2, Vec3 &outU) const
{
RVec3 p1 = mBody1->GetCenterOfMassTransform() * mLocalSpacePosition1;
RVec3 p2 = mBody2->GetCenterOfMassTransform() * mLocalSpacePosition2;
outR1PlusU = Vec3(p2 - mBody1->GetCenterOfMassPosition()); // r1 + u = (p1 - x1) + (p2 - p1) = p2 - x1
outR2 = Vec3(p2 - mBody2->GetCenterOfMassPosition());
outU = Vec3(p2 - p1);
}
Quat SixDOFConstraint::GetRotationInConstraintSpace() const
{
// Let b1, b2 be the center of mass transform of body1 and body2 (For body1 this is mBody1->GetCenterOfMassTransform())
// Let c1, c2 be the transform that takes a vector from constraint space to local space of body1 and body2 (For body1 this is Mat44::sRotationTranslation(mConstraintToBody1, mLocalSpacePosition1))
// Let q be the rotation of the constraint in constraint space
// b2 takes a vector from the local space of body2 to world space
// To express this in terms of b1: b2 = b1 * c1 * q * c2^-1
// c2^-1 goes from local body 2 space to constraint space
// q rotates the constraint
// c1 goes from constraint space to body 1 local space
// b1 goes from body 1 local space to world space
// So when the body rotations are given, q = (b1 * c1)^-1 * b2 c2
// Or: q = (q1 * c1)^-1 * (q2 * c2) if we're only interested in rotations
return (mBody1->GetRotation() * mConstraintToBody1).Conjugated() * mBody2->GetRotation() * mConstraintToBody2;
}
void SixDOFConstraint::CacheTranslationMotorActive()
{
mTranslationMotorActive = mMotorState[EAxis::TranslationX] != EMotorState::Off
|| mMotorState[EAxis::TranslationY] != EMotorState::Off
|| mMotorState[EAxis::TranslationZ] != EMotorState::Off
|| HasFriction(EAxis::TranslationX)
|| HasFriction(EAxis::TranslationY)
|| HasFriction(EAxis::TranslationZ);
}
void SixDOFConstraint::CacheRotationMotorActive()
{
mRotationMotorActive = mMotorState[EAxis::RotationX] != EMotorState::Off
|| mMotorState[EAxis::RotationY] != EMotorState::Off
|| mMotorState[EAxis::RotationZ] != EMotorState::Off
|| HasFriction(EAxis::RotationX)
|| HasFriction(EAxis::RotationY)
|| HasFriction(EAxis::RotationZ);
}
void SixDOFConstraint::CacheRotationPositionMotorActive()
{
mRotationPositionMotorActive = 0;
for (int i = 0; i < 3; ++i)
if (mMotorState[EAxis::RotationX + i] == EMotorState::Position)
mRotationPositionMotorActive |= 1 << i;
}
void SixDOFConstraint::CacheHasSpringLimits()
{
mHasSpringLimits = mLimitsSpringSettings[EAxis::TranslationX].mFrequency > 0.0f
|| mLimitsSpringSettings[EAxis::TranslationY].mFrequency > 0.0f
|| mLimitsSpringSettings[EAxis::TranslationZ].mFrequency > 0.0f;
}
void SixDOFConstraint::SetMotorState(EAxis inAxis, EMotorState inState)
{
JPH_ASSERT(inState == EMotorState::Off || mMotorSettings[inAxis].IsValid());
if (mMotorState[inAxis] != inState)
{
mMotorState[inAxis] = inState;
// Ensure that warm starting next frame doesn't apply any impulses (motor parts are repurposed for different modes)
if (inAxis >= EAxis::TranslationX && inAxis <= EAxis::TranslationZ)
{
mMotorTranslationConstraintPart[inAxis - EAxis::TranslationX].Deactivate();
CacheTranslationMotorActive();
}
else
{
JPH_ASSERT(inAxis >= EAxis::RotationX && inAxis <= EAxis::RotationZ);
mMotorRotationConstraintPart[inAxis - EAxis::RotationX].Deactivate();
CacheRotationMotorActive();
CacheRotationPositionMotorActive();
}
}
}
void SixDOFConstraint::SetTargetOrientationCS(QuatArg inOrientation)
{
Quat q_swing, q_twist;
inOrientation.GetSwingTwist(q_swing, q_twist);
uint clamped_axis;
mSwingTwistConstraintPart.ClampSwingTwist(q_swing, q_twist, clamped_axis);
if (clamped_axis != 0)
mTargetOrientation = q_swing * q_twist;
else
mTargetOrientation = inOrientation;
}
void SixDOFConstraint::SetupVelocityConstraint(float inDeltaTime)
{
// Get body rotations
Quat rotation1 = mBody1->GetRotation();
Quat rotation2 = mBody2->GetRotation();
// Quaternion that rotates from body1's constraint space to world space
Quat constraint_body1_to_world = rotation1 * mConstraintToBody1;
// Store world space axis of constraint space
Mat44 translation_axis_mat = Mat44::sRotation(constraint_body1_to_world);
for (int i = 0; i < 3; ++i)
mTranslationAxis[i] = translation_axis_mat.GetColumn3(i);
if (IsTranslationFullyConstrained())
{
// All translation locked: Setup point constraint
mPointConstraintPart.CalculateConstraintProperties(*mBody1, Mat44::sRotation(rotation1), mLocalSpacePosition1, *mBody2, Mat44::sRotation(rotation2), mLocalSpacePosition2);
}
else if (IsTranslationConstrained() || mTranslationMotorActive)
{
// Update world space positions (the bodies may have moved)
Vec3 r1_plus_u, r2, u;
GetPositionConstraintProperties(r1_plus_u, r2, u);
// Setup axis constraint parts
for (int i = 0; i < 3; ++i)
{
EAxis axis = EAxis(EAxis::TranslationX + i);
Vec3 translation_axis = mTranslationAxis[i];
// Calculate displacement along this axis
float d = translation_axis.Dot(u);
mDisplacement[i] = d; // Store for SolveVelocityConstraint
// Setup limit constraint
bool constraint_active = false;
float constraint_value = 0.0f;
if (IsFixedAxis(axis))
{
// When constraint is fixed it is always active
constraint_value = d - mLimitMin[i];
constraint_active = true;
}
else if (!IsFreeAxis(axis))
{
// When constraint is limited, it is only active when outside of the allowed range
if (d <= mLimitMin[i])
{
constraint_value = d - mLimitMin[i];
constraint_active = true;
}
else if (d >= mLimitMax[i])
{
constraint_value = d - mLimitMax[i];
constraint_active = true;
}
}
if (constraint_active)
mTranslationConstraintPart[i].CalculateConstraintPropertiesWithSettings(inDeltaTime, *mBody1, r1_plus_u, *mBody2, r2, translation_axis, 0.0f, constraint_value, mLimitsSpringSettings[i]);
else
mTranslationConstraintPart[i].Deactivate();
// Setup motor constraint
switch (mMotorState[i])
{
case EMotorState::Off:
if (HasFriction(axis))
mMotorTranslationConstraintPart[i].CalculateConstraintProperties(*mBody1, r1_plus_u, *mBody2, r2, translation_axis);
else
mMotorTranslationConstraintPart[i].Deactivate();
break;
case EMotorState::Velocity:
mMotorTranslationConstraintPart[i].CalculateConstraintProperties(*mBody1, r1_plus_u, *mBody2, r2, translation_axis, -mTargetVelocity[i]);
break;
case EMotorState::Position:
{
const SpringSettings &spring_settings = mMotorSettings[i].mSpringSettings;
if (spring_settings.HasStiffness())
mMotorTranslationConstraintPart[i].CalculateConstraintPropertiesWithSettings(inDeltaTime, *mBody1, r1_plus_u, *mBody2, r2, translation_axis, 0.0f, translation_axis.Dot(u) - mTargetPosition[i], spring_settings);
else
mMotorTranslationConstraintPart[i].Deactivate();
break;
}
}
}
}
// Setup rotation constraints
if (IsRotationFullyConstrained())
{
// All rotation locked: Setup rotation constraint
mRotationConstraintPart.CalculateConstraintProperties(*mBody1, Mat44::sRotation(mBody1->GetRotation()), *mBody2, Mat44::sRotation(mBody2->GetRotation()));
}
else if (IsRotationConstrained() || mRotationMotorActive)
{
// GetRotationInConstraintSpace without redoing the calculation of constraint_body1_to_world
Quat constraint_body2_to_world = mBody2->GetRotation() * mConstraintToBody2;
Quat q = constraint_body1_to_world.Conjugated() * constraint_body2_to_world;
// Use swing twist constraint part
if (IsRotationConstrained())
mSwingTwistConstraintPart.CalculateConstraintProperties(*mBody1, *mBody2, q, constraint_body1_to_world);
else
mSwingTwistConstraintPart.Deactivate();
if (mRotationMotorActive)
{
// Calculate rotation motor axis
Mat44 ws_axis = Mat44::sRotation(constraint_body2_to_world);
for (int i = 0; i < 3; ++i)
mRotationAxis[i] = ws_axis.GetColumn3(i);
// Get target orientation along the shortest path from q
Quat target_orientation = q.Dot(mTargetOrientation) > 0.0f? mTargetOrientation : -mTargetOrientation;
// The definition of the constraint rotation q:
// R2 * ConstraintToBody2 = R1 * ConstraintToBody1 * q (1)
//
// R2' is the rotation of body 2 when reaching the target_orientation:
// R2' * ConstraintToBody2 = R1 * ConstraintToBody1 * target_orientation (2)
//
// The difference in body 2 space:
// R2' = R2 * diff_body2 (3)
//
// We want to specify the difference in the constraint space of body 2:
// diff_body2 = ConstraintToBody2 * diff * ConstraintToBody2^* (4)
//
// Extracting R2' from 2: R2' = R1 * ConstraintToBody1 * target_orientation * ConstraintToBody2^* (5)
// Combining 3 & 4: R2' = R2 * ConstraintToBody2 * diff * ConstraintToBody2^* (6)
// Combining 1 & 6: R2' = R1 * ConstraintToBody1 * q * diff * ConstraintToBody2^* (7)
// Combining 5 & 7: R1 * ConstraintToBody1 * target_orientation * ConstraintToBody2^* = R1 * ConstraintToBody1 * q * diff * ConstraintToBody2^*
// <=> target_orientation = q * diff
// <=> diff = q^* * target_orientation
Quat diff = q.Conjugated() * target_orientation;
// Project diff so that only rotation around axis that have a position motor are remaining
Quat projected_diff;
switch (mRotationPositionMotorActive)
{
case 0b001:
// Keep only rotation around X
projected_diff = diff.GetTwist(Vec3::sAxisX());
break;
case 0b010:
// Keep only rotation around Y
projected_diff = diff.GetTwist(Vec3::sAxisY());
break;
case 0b100:
// Keep only rotation around Z
projected_diff = diff.GetTwist(Vec3::sAxisZ());
break;
case 0b011:
// Remove rotation around Z
// q = swing_xy * twist_z <=> swing_xy = q * twist_z^*
projected_diff = diff * diff.GetTwist(Vec3::sAxisZ()).Conjugated();
break;
case 0b101:
// Remove rotation around Y
// q = swing_xz * twist_y <=> swing_xz = q * twist_y^*
projected_diff = diff * diff.GetTwist(Vec3::sAxisY()).Conjugated();
break;
case 0b110:
// Remove rotation around X
// q = swing_yz * twist_x <=> swing_yz = q * twist_x^*
projected_diff = diff * diff.GetTwist(Vec3::sAxisX()).Conjugated();
break;
case 0b111:
default: // All motors off is handled here but the results are unused
// Keep entire rotation
projected_diff = diff;
break;
}
// Approximate error angles
// The imaginary part of a quaternion is rotation_axis * sin(angle / 2)
// If angle is small, sin(x) = x so angle[i] ~ 2.0f * rotation_axis[i]
// We'll be making small time steps, so if the angle is not small at least the sign will be correct and we'll move in the right direction
Vec3 rotation_error = -2.0f * projected_diff.GetXYZ();
// Setup motors
for (int i = 0; i < 3; ++i)
{
EAxis axis = EAxis(EAxis::RotationX + i);
Vec3 rotation_axis = mRotationAxis[i];
switch (mMotorState[axis])
{
case EMotorState::Off:
if (HasFriction(axis))
mMotorRotationConstraintPart[i].CalculateConstraintProperties(*mBody1, *mBody2, rotation_axis);
else
mMotorRotationConstraintPart[i].Deactivate();
break;
case EMotorState::Velocity:
mMotorRotationConstraintPart[i].CalculateConstraintProperties(*mBody1, *mBody2, rotation_axis, -mTargetAngularVelocity[i]);
break;
case EMotorState::Position:
{
const SpringSettings &spring_settings = mMotorSettings[axis].mSpringSettings;
if (spring_settings.HasStiffness())
mMotorRotationConstraintPart[i].CalculateConstraintPropertiesWithSettings(inDeltaTime, *mBody1, *mBody2, rotation_axis, 0.0f, rotation_error[i], spring_settings);
else
mMotorRotationConstraintPart[i].Deactivate();
break;
}
}
}
}
}
}
void SixDOFConstraint::ResetWarmStart()
{
for (AxisConstraintPart &c : mMotorTranslationConstraintPart)
c.Deactivate();
for (AngleConstraintPart &c : mMotorRotationConstraintPart)
c.Deactivate();
mRotationConstraintPart.Deactivate();
mSwingTwistConstraintPart.Deactivate();
mPointConstraintPart.Deactivate();
for (AxisConstraintPart &c : mTranslationConstraintPart)
c.Deactivate();
}
void SixDOFConstraint::WarmStartVelocityConstraint(float inWarmStartImpulseRatio)
{
// Warm start translation motors
if (mTranslationMotorActive)
for (int i = 0; i < 3; ++i)
if (mMotorTranslationConstraintPart[i].IsActive())
mMotorTranslationConstraintPart[i].WarmStart(*mBody1, *mBody2, mTranslationAxis[i], inWarmStartImpulseRatio);
// Warm start rotation motors
if (mRotationMotorActive)
for (AngleConstraintPart &c : mMotorRotationConstraintPart)
if (c.IsActive())
c.WarmStart(*mBody1, *mBody2, inWarmStartImpulseRatio);
// Warm start rotation constraints
if (IsRotationFullyConstrained())
mRotationConstraintPart.WarmStart(*mBody1, *mBody2, inWarmStartImpulseRatio);
else if (IsRotationConstrained())
mSwingTwistConstraintPart.WarmStart(*mBody1, *mBody2, inWarmStartImpulseRatio);
// Warm start translation constraints
if (IsTranslationFullyConstrained())
mPointConstraintPart.WarmStart(*mBody1, *mBody2, inWarmStartImpulseRatio);
else if (IsTranslationConstrained())
for (int i = 0; i < 3; ++i)
if (mTranslationConstraintPart[i].IsActive())
mTranslationConstraintPart[i].WarmStart(*mBody1, *mBody2, mTranslationAxis[i], inWarmStartImpulseRatio);
}
bool SixDOFConstraint::SolveVelocityConstraint(float inDeltaTime)
{
bool impulse = false;
// Solve translation motor
if (mTranslationMotorActive)
for (int i = 0; i < 3; ++i)
if (mMotorTranslationConstraintPart[i].IsActive())
switch (mMotorState[i])
{
case EMotorState::Off:
{
// Apply friction only
float max_lambda = mMaxFriction[i] * inDeltaTime;
impulse |= mMotorTranslationConstraintPart[i].SolveVelocityConstraint(*mBody1, *mBody2, mTranslationAxis[i], -max_lambda, max_lambda);
break;
}
case EMotorState::Velocity:
case EMotorState::Position:
// Drive motor
impulse |= mMotorTranslationConstraintPart[i].SolveVelocityConstraint(*mBody1, *mBody2, mTranslationAxis[i], inDeltaTime * mMotorSettings[i].mMinForceLimit, inDeltaTime * mMotorSettings[i].mMaxForceLimit);
break;
}
// Solve rotation motor
if (mRotationMotorActive)
for (int i = 0; i < 3; ++i)
{
EAxis axis = EAxis(EAxis::RotationX + i);
if (mMotorRotationConstraintPart[i].IsActive())
switch (mMotorState[axis])
{
case EMotorState::Off:
{
// Apply friction only
float max_lambda = mMaxFriction[axis] * inDeltaTime;
impulse |= mMotorRotationConstraintPart[i].SolveVelocityConstraint(*mBody1, *mBody2, mRotationAxis[i], -max_lambda, max_lambda);
break;
}
case EMotorState::Velocity:
case EMotorState::Position:
// Drive motor
impulse |= mMotorRotationConstraintPart[i].SolveVelocityConstraint(*mBody1, *mBody2, mRotationAxis[i], inDeltaTime * mMotorSettings[axis].mMinTorqueLimit, inDeltaTime * mMotorSettings[axis].mMaxTorqueLimit);
break;
}
}
// Solve rotation constraint
if (IsRotationFullyConstrained())
impulse |= mRotationConstraintPart.SolveVelocityConstraint(*mBody1, *mBody2);
else if (IsRotationConstrained())
impulse |= mSwingTwistConstraintPart.SolveVelocityConstraint(*mBody1, *mBody2);
// Solve position constraint
if (IsTranslationFullyConstrained())
impulse |= mPointConstraintPart.SolveVelocityConstraint(*mBody1, *mBody2);
else if (IsTranslationConstrained())
for (int i = 0; i < 3; ++i)
if (mTranslationConstraintPart[i].IsActive())
{
// If the axis is not fixed it must be limited (or else the constraint would not be active)
// Calculate the min and max constraint force based on on which side we're limited
float limit_min = -FLT_MAX, limit_max = FLT_MAX;
if (!IsFixedAxis(EAxis(EAxis::TranslationX + i)))
{
JPH_ASSERT(!IsFreeAxis(EAxis(EAxis::TranslationX + i)));
if (mDisplacement[i] <= mLimitMin[i])
limit_min = 0;
else if (mDisplacement[i] >= mLimitMax[i])
limit_max = 0;
}
impulse |= mTranslationConstraintPart[i].SolveVelocityConstraint(*mBody1, *mBody2, mTranslationAxis[i], limit_min, limit_max);
}
return impulse;
}
bool SixDOFConstraint::SolvePositionConstraint(float inDeltaTime, float inBaumgarte)
{
bool impulse = false;
if (IsRotationFullyConstrained())
{
// Rotation locked: Solve rotation constraint
// Inverse of initial rotation from body 1 to body 2 in body 1 space
// Definition of initial orientation r0: q2 = q1 r0
// Initial rotation (see: GetRotationInConstraintSpace): q2 = q1 c1 c2^-1
// So: r0^-1 = (c1 c2^-1)^-1 = c2 * c1^-1
Quat constraint_to_body1 = mConstraintToBody1 * Quat::sEulerAngles(GetRotationLimitsMin());
Quat inv_initial_orientation = mConstraintToBody2 * constraint_to_body1.Conjugated();
// Solve rotation violations
mRotationConstraintPart.CalculateConstraintProperties(*mBody1, Mat44::sRotation(mBody1->GetRotation()), *mBody2, Mat44::sRotation(mBody2->GetRotation()));
impulse |= mRotationConstraintPart.SolvePositionConstraint(*mBody1, *mBody2, inv_initial_orientation, inBaumgarte);
}
else if (IsRotationConstrained())
{
// Rotation partially constraint
// Solve rotation violations
Quat q = GetRotationInConstraintSpace();
impulse |= mSwingTwistConstraintPart.SolvePositionConstraint(*mBody1, *mBody2, q, mConstraintToBody1, mConstraintToBody2, inBaumgarte);
}
// Solve position violations
if (IsTranslationFullyConstrained())
{
// Translation locked: Solve point constraint
Vec3 local_space_position1 = mLocalSpacePosition1 + mConstraintToBody1 * GetTranslationLimitsMin();
mPointConstraintPart.CalculateConstraintProperties(*mBody1, Mat44::sRotation(mBody1->GetRotation()), local_space_position1, *mBody2, Mat44::sRotation(mBody2->GetRotation()), mLocalSpacePosition2);
impulse |= mPointConstraintPart.SolvePositionConstraint(*mBody1, *mBody2, inBaumgarte);
}
else if (IsTranslationConstrained())
{
// Translation partially locked: Solve per axis
for (int i = 0; i < 3; ++i)
if (mLimitsSpringSettings[i].mFrequency <= 0.0f) // If not soft limit
{
// Update world space positions (the bodies may have moved)
Vec3 r1_plus_u, r2, u;
GetPositionConstraintProperties(r1_plus_u, r2, u);
// Quaternion that rotates from body1's constraint space to world space
Quat constraint_body1_to_world = mBody1->GetRotation() * mConstraintToBody1;
// Calculate axis
Vec3 translation_axis;
switch (i)
{
case 0: translation_axis = constraint_body1_to_world.RotateAxisX(); break;
case 1: translation_axis = constraint_body1_to_world.RotateAxisY(); break;
default: JPH_ASSERT(i == 2); translation_axis = constraint_body1_to_world.RotateAxisZ(); break;
}
// Determine position error
float error = 0.0f;
EAxis axis(EAxis(EAxis::TranslationX + i));
if (IsFixedAxis(axis))
error = u.Dot(translation_axis) - mLimitMin[axis];
else if (!IsFreeAxis(axis))
{
float displacement = u.Dot(translation_axis);
if (displacement <= mLimitMin[axis])
error = displacement - mLimitMin[axis];
else if (displacement >= mLimitMax[axis])
error = displacement - mLimitMax[axis];
}
if (error != 0.0f)
{
// Setup axis constraint part and solve it
mTranslationConstraintPart[i].CalculateConstraintProperties(*mBody1, r1_plus_u, *mBody2, r2, translation_axis);
impulse |= mTranslationConstraintPart[i].SolvePositionConstraint(*mBody1, *mBody2, translation_axis, error, inBaumgarte);
}
}
}
return impulse;
}
#ifdef JPH_DEBUG_RENDERER
void SixDOFConstraint::DrawConstraint(DebugRenderer *inRenderer) const
{
// Get constraint properties in world space
RVec3 position1 = mBody1->GetCenterOfMassTransform() * mLocalSpacePosition1;
Quat rotation1 = mBody1->GetRotation() * mConstraintToBody1;
Quat rotation2 = mBody2->GetRotation() * mConstraintToBody2;
// Draw constraint orientation
inRenderer->DrawCoordinateSystem(RMat44::sRotationTranslation(rotation1, position1), mDrawConstraintSize);
if ((IsRotationConstrained() || mRotationPositionMotorActive != 0) && !IsRotationFullyConstrained())
{
// Draw current swing and twist
Quat q = GetRotationInConstraintSpace();
Quat q_swing, q_twist;
q.GetSwingTwist(q_swing, q_twist);
inRenderer->DrawLine(position1, position1 + mDrawConstraintSize * (rotation1 * q_twist).RotateAxisY(), Color::sWhite);
inRenderer->DrawLine(position1, position1 + mDrawConstraintSize * (rotation1 * q_swing).RotateAxisX(), Color::sWhite);
}
// Draw target rotation
Quat m_swing, m_twist;
mTargetOrientation.GetSwingTwist(m_swing, m_twist);
if (mMotorState[EAxis::RotationX] == EMotorState::Position)
inRenderer->DrawLine(position1, position1 + mDrawConstraintSize * (rotation1 * m_twist).RotateAxisY(), Color::sYellow);
if (mMotorState[EAxis::RotationY] == EMotorState::Position || mMotorState[EAxis::RotationZ] == EMotorState::Position)
inRenderer->DrawLine(position1, position1 + mDrawConstraintSize * (rotation1 * m_swing).RotateAxisX(), Color::sYellow);
// Draw target angular velocity
Vec3 target_angular_velocity = Vec3::sZero();
for (int i = 0; i < 3; ++i)
if (mMotorState[EAxis::RotationX + i] == EMotorState::Velocity)
target_angular_velocity.SetComponent(i, mTargetAngularVelocity[i]);
if (target_angular_velocity != Vec3::sZero())
inRenderer->DrawArrow(position1, position1 + rotation2 * target_angular_velocity, Color::sRed, 0.1f);
}
void SixDOFConstraint::DrawConstraintLimits(DebugRenderer *inRenderer) const
{
// Get matrix that transforms from constraint space to world space
RMat44 constraint_body1_to_world = RMat44::sRotationTranslation(mBody1->GetRotation() * mConstraintToBody1, mBody1->GetCenterOfMassTransform() * mLocalSpacePosition1);
// Draw limits
if (mSwingTwistConstraintPart.GetSwingType() == ESwingType::Pyramid)
inRenderer->DrawSwingPyramidLimits(constraint_body1_to_world, mLimitMin[EAxis::RotationY], mLimitMax[EAxis::RotationY], mLimitMin[EAxis::RotationZ], mLimitMax[EAxis::RotationZ], mDrawConstraintSize, Color::sGreen, DebugRenderer::ECastShadow::Off);
else
inRenderer->DrawSwingConeLimits(constraint_body1_to_world, mLimitMax[EAxis::RotationY], mLimitMax[EAxis::RotationZ], mDrawConstraintSize, Color::sGreen, DebugRenderer::ECastShadow::Off);
inRenderer->DrawPie(constraint_body1_to_world.GetTranslation(), mDrawConstraintSize, constraint_body1_to_world.GetAxisX(), constraint_body1_to_world.GetAxisY(), mLimitMin[EAxis::RotationX], mLimitMax[EAxis::RotationX], Color::sPurple, DebugRenderer::ECastShadow::Off);
}
#endif // JPH_DEBUG_RENDERER
void SixDOFConstraint::SaveState(StateRecorder &inStream) const
{
TwoBodyConstraint::SaveState(inStream);
for (const AxisConstraintPart &c : mTranslationConstraintPart)
c.SaveState(inStream);
mPointConstraintPart.SaveState(inStream);
mSwingTwistConstraintPart.SaveState(inStream);
mRotationConstraintPart.SaveState(inStream);
for (const AxisConstraintPart &c : mMotorTranslationConstraintPart)
c.SaveState(inStream);
for (const AngleConstraintPart &c : mMotorRotationConstraintPart)
c.SaveState(inStream);
inStream.Write(mMotorState);
inStream.Write(mTargetVelocity);
inStream.Write(mTargetAngularVelocity);
inStream.Write(mTargetPosition);
inStream.Write(mTargetOrientation);
}
void SixDOFConstraint::RestoreState(StateRecorder &inStream)
{
TwoBodyConstraint::RestoreState(inStream);
for (AxisConstraintPart &c : mTranslationConstraintPart)
c.RestoreState(inStream);
mPointConstraintPart.RestoreState(inStream);
mSwingTwistConstraintPart.RestoreState(inStream);
mRotationConstraintPart.RestoreState(inStream);
for (AxisConstraintPart &c : mMotorTranslationConstraintPart)
c.RestoreState(inStream);
for (AngleConstraintPart &c : mMotorRotationConstraintPart)
c.RestoreState(inStream);
inStream.Read(mMotorState);
inStream.Read(mTargetVelocity);
inStream.Read(mTargetAngularVelocity);
inStream.Read(mTargetPosition);
inStream.Read(mTargetOrientation);
CacheTranslationMotorActive();
CacheRotationMotorActive();
CacheRotationPositionMotorActive();
}
Ref<ConstraintSettings> SixDOFConstraint::GetConstraintSettings() const
{
SixDOFConstraintSettings *settings = new SixDOFConstraintSettings;
ToConstraintSettings(*settings);
settings->mSpace = EConstraintSpace::LocalToBodyCOM;
settings->mPosition1 = RVec3(mLocalSpacePosition1);
settings->mAxisX1 = mConstraintToBody1.RotateAxisX();
settings->mAxisY1 = mConstraintToBody1.RotateAxisY();
settings->mPosition2 = RVec3(mLocalSpacePosition2);
settings->mAxisX2 = mConstraintToBody2.RotateAxisX();
settings->mAxisY2 = mConstraintToBody2.RotateAxisY();
settings->mSwingType = mSwingTwistConstraintPart.GetSwingType();
memcpy(settings->mLimitMin, mLimitMin, sizeof(mLimitMin));
memcpy(settings->mLimitMax, mLimitMax, sizeof(mLimitMax));
memcpy(settings->mMaxFriction, mMaxFriction, sizeof(mMaxFriction));
for (int i = 0; i < EAxis::Num; ++i)
settings->mMotorSettings[i] = mMotorSettings[i];
return settings;
}
JPH_NAMESPACE_END