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Diffstat (limited to 'servers/physics_3d/joints/hinge_joint_3d_sw.cpp')
| -rw-r--r-- | servers/physics_3d/joints/hinge_joint_3d_sw.cpp | 450 |
1 files changed, 450 insertions, 0 deletions
diff --git a/servers/physics_3d/joints/hinge_joint_3d_sw.cpp b/servers/physics_3d/joints/hinge_joint_3d_sw.cpp new file mode 100644 index 0000000000..57605aac7b --- /dev/null +++ b/servers/physics_3d/joints/hinge_joint_3d_sw.cpp @@ -0,0 +1,450 @@ +/*************************************************************************/ +/* hinge_joint_sw.cpp */ +/*************************************************************************/ +/* This file is part of: */ +/* GODOT ENGINE */ +/* https://godotengine.org */ +/*************************************************************************/ +/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */ +/* Copyright (c) 2014-2020 Godot Engine contributors (cf. AUTHORS.md). */ +/* */ +/* Permission is hereby granted, free of charge, to any person obtaining */ +/* a copy of this software and associated documentation files (the */ +/* "Software"), to deal in the Software without restriction, including */ +/* without limitation the rights to use, copy, modify, merge, publish, */ +/* distribute, sublicense, and/or sell copies of the Software, and to */ +/* permit persons to whom the Software is furnished to do so, subject to */ +/* the following conditions: */ +/* */ +/* The above copyright notice and this permission notice shall be */ +/* included in all copies or substantial portions of the Software. */ +/* */ +/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */ +/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */ +/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/ +/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */ +/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */ +/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */ +/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ +/*************************************************************************/ + +/* +Adapted to Godot from the Bullet library. +*/ + +/* +Bullet Continuous Collision Detection and Physics Library +Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/ + +This software is provided 'as-is', without any express or implied warranty. +In no event will the authors be held liable for any damages arising from the use of this software. +Permission is granted to anyone to use this software for any purpose, +including commercial applications, and to alter it and redistribute it freely, +subject to the following restrictions: + +1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. +2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. +3. This notice may not be removed or altered from any source distribution. +*/ + +#include "hinge_joint_3d_sw.h" + +static void plane_space(const Vector3 &n, Vector3 &p, Vector3 &q) { + + if (Math::abs(n.z) > Math_SQRT12) { + // choose p in y-z plane + real_t a = n[1] * n[1] + n[2] * n[2]; + real_t k = 1.0 / Math::sqrt(a); + p = Vector3(0, -n[2] * k, n[1] * k); + // set q = n x p + q = Vector3(a * k, -n[0] * p[2], n[0] * p[1]); + } else { + // choose p in x-y plane + real_t a = n.x * n.x + n.y * n.y; + real_t k = 1.0 / Math::sqrt(a); + p = Vector3(-n.y * k, n.x * k, 0); + // set q = n x p + q = Vector3(-n.z * p.y, n.z * p.x, a * k); + } +} + +HingeJoint3DSW::HingeJoint3DSW(Body3DSW *rbA, Body3DSW *rbB, const Transform &frameA, const Transform &frameB) : + Joint3DSW(_arr, 2) { + + A = rbA; + B = rbB; + + m_rbAFrame = frameA; + m_rbBFrame = frameB; + // flip axis + m_rbBFrame.basis[0][2] *= real_t(-1.); + m_rbBFrame.basis[1][2] *= real_t(-1.); + m_rbBFrame.basis[2][2] *= real_t(-1.); + + //start with free + m_lowerLimit = Math_PI; + m_upperLimit = -Math_PI; + + m_useLimit = false; + m_biasFactor = 0.3f; + m_relaxationFactor = 1.0f; + m_limitSoftness = 0.9f; + m_solveLimit = false; + + tau = 0.3; + + m_angularOnly = false; + m_enableAngularMotor = false; + + A->add_constraint(this, 0); + B->add_constraint(this, 1); +} + +HingeJoint3DSW::HingeJoint3DSW(Body3DSW *rbA, Body3DSW *rbB, const Vector3 &pivotInA, const Vector3 &pivotInB, + const Vector3 &axisInA, const Vector3 &axisInB) : + Joint3DSW(_arr, 2) { + + A = rbA; + B = rbB; + + m_rbAFrame.origin = pivotInA; + + // since no frame is given, assume this to be zero angle and just pick rb transform axis + Vector3 rbAxisA1 = rbA->get_transform().basis.get_axis(0); + + Vector3 rbAxisA2; + real_t projection = axisInA.dot(rbAxisA1); + if (projection >= 1.0f - CMP_EPSILON) { + rbAxisA1 = -rbA->get_transform().basis.get_axis(2); + rbAxisA2 = rbA->get_transform().basis.get_axis(1); + } else if (projection <= -1.0f + CMP_EPSILON) { + rbAxisA1 = rbA->get_transform().basis.get_axis(2); + rbAxisA2 = rbA->get_transform().basis.get_axis(1); + } else { + rbAxisA2 = axisInA.cross(rbAxisA1); + rbAxisA1 = rbAxisA2.cross(axisInA); + } + + m_rbAFrame.basis = Basis(rbAxisA1.x, rbAxisA2.x, axisInA.x, + rbAxisA1.y, rbAxisA2.y, axisInA.y, + rbAxisA1.z, rbAxisA2.z, axisInA.z); + + Quat rotationArc = Quat(axisInA, axisInB); + Vector3 rbAxisB1 = rotationArc.xform(rbAxisA1); + Vector3 rbAxisB2 = axisInB.cross(rbAxisB1); + + m_rbBFrame.origin = pivotInB; + m_rbBFrame.basis = Basis(rbAxisB1.x, rbAxisB2.x, -axisInB.x, + rbAxisB1.y, rbAxisB2.y, -axisInB.y, + rbAxisB1.z, rbAxisB2.z, -axisInB.z); + + //start with free + m_lowerLimit = Math_PI; + m_upperLimit = -Math_PI; + + m_useLimit = false; + m_biasFactor = 0.3f; + m_relaxationFactor = 1.0f; + m_limitSoftness = 0.9f; + m_solveLimit = false; + + tau = 0.3; + + m_angularOnly = false; + m_enableAngularMotor = false; + + A->add_constraint(this, 0); + B->add_constraint(this, 1); +} + +bool HingeJoint3DSW::setup(real_t p_step) { + + m_appliedImpulse = real_t(0.); + + if (!m_angularOnly) { + Vector3 pivotAInW = A->get_transform().xform(m_rbAFrame.origin); + Vector3 pivotBInW = B->get_transform().xform(m_rbBFrame.origin); + Vector3 relPos = pivotBInW - pivotAInW; + + Vector3 normal[3]; + if (Math::is_zero_approx(relPos.length_squared())) { + normal[0] = Vector3(real_t(1.0), 0, 0); + } else { + normal[0] = relPos.normalized(); + } + + plane_space(normal[0], normal[1], normal[2]); + + for (int i = 0; i < 3; i++) { + memnew_placement(&m_jac[i], JacobianEntry3DSW( + A->get_principal_inertia_axes().transposed(), + B->get_principal_inertia_axes().transposed(), + pivotAInW - A->get_transform().origin - A->get_center_of_mass(), + pivotBInW - B->get_transform().origin - B->get_center_of_mass(), + normal[i], + A->get_inv_inertia(), + A->get_inv_mass(), + B->get_inv_inertia(), + B->get_inv_mass())); + } + } + + //calculate two perpendicular jointAxis, orthogonal to hingeAxis + //these two jointAxis require equal angular velocities for both bodies + + //this is unused for now, it's a todo + Vector3 jointAxis0local; + Vector3 jointAxis1local; + + plane_space(m_rbAFrame.basis.get_axis(2), jointAxis0local, jointAxis1local); + + Vector3 jointAxis0 = A->get_transform().basis.xform(jointAxis0local); + Vector3 jointAxis1 = A->get_transform().basis.xform(jointAxis1local); + Vector3 hingeAxisWorld = A->get_transform().basis.xform(m_rbAFrame.basis.get_axis(2)); + + memnew_placement(&m_jacAng[0], JacobianEntry3DSW(jointAxis0, + A->get_principal_inertia_axes().transposed(), + B->get_principal_inertia_axes().transposed(), + A->get_inv_inertia(), + B->get_inv_inertia())); + + memnew_placement(&m_jacAng[1], JacobianEntry3DSW(jointAxis1, + A->get_principal_inertia_axes().transposed(), + B->get_principal_inertia_axes().transposed(), + A->get_inv_inertia(), + B->get_inv_inertia())); + + memnew_placement(&m_jacAng[2], JacobianEntry3DSW(hingeAxisWorld, + A->get_principal_inertia_axes().transposed(), + B->get_principal_inertia_axes().transposed(), + A->get_inv_inertia(), + B->get_inv_inertia())); + + // Compute limit information + real_t hingeAngle = get_hinge_angle(); + + //set bias, sign, clear accumulator + m_correction = real_t(0.); + m_limitSign = real_t(0.); + m_solveLimit = false; + m_accLimitImpulse = real_t(0.); + + //if (m_lowerLimit < m_upperLimit) + if (m_useLimit && m_lowerLimit <= m_upperLimit) { + //if (hingeAngle <= m_lowerLimit*m_limitSoftness) + if (hingeAngle <= m_lowerLimit) { + m_correction = (m_lowerLimit - hingeAngle); + m_limitSign = 1.0f; + m_solveLimit = true; + } + //else if (hingeAngle >= m_upperLimit*m_limitSoftness) + else if (hingeAngle >= m_upperLimit) { + m_correction = m_upperLimit - hingeAngle; + m_limitSign = -1.0f; + m_solveLimit = true; + } + } + + //Compute K = J*W*J' for hinge axis + Vector3 axisA = A->get_transform().basis.xform(m_rbAFrame.basis.get_axis(2)); + m_kHinge = 1.0f / (A->compute_angular_impulse_denominator(axisA) + + B->compute_angular_impulse_denominator(axisA)); + + return true; +} + +void HingeJoint3DSW::solve(real_t p_step) { + + Vector3 pivotAInW = A->get_transform().xform(m_rbAFrame.origin); + Vector3 pivotBInW = B->get_transform().xform(m_rbBFrame.origin); + + //real_t tau = real_t(0.3); + + //linear part + if (!m_angularOnly) { + Vector3 rel_pos1 = pivotAInW - A->get_transform().origin; + Vector3 rel_pos2 = pivotBInW - B->get_transform().origin; + + Vector3 vel1 = A->get_velocity_in_local_point(rel_pos1); + Vector3 vel2 = B->get_velocity_in_local_point(rel_pos2); + Vector3 vel = vel1 - vel2; + + for (int i = 0; i < 3; i++) { + const Vector3 &normal = m_jac[i].m_linearJointAxis; + real_t jacDiagABInv = real_t(1.) / m_jac[i].getDiagonal(); + + real_t rel_vel; + rel_vel = normal.dot(vel); + //positional error (zeroth order error) + real_t depth = -(pivotAInW - pivotBInW).dot(normal); //this is the error projected on the normal + real_t impulse = depth * tau / p_step * jacDiagABInv - rel_vel * jacDiagABInv; + m_appliedImpulse += impulse; + Vector3 impulse_vector = normal * impulse; + A->apply_impulse(pivotAInW - A->get_transform().origin, impulse_vector); + B->apply_impulse(pivotBInW - B->get_transform().origin, -impulse_vector); + } + } + + { + ///solve angular part + + // get axes in world space + Vector3 axisA = A->get_transform().basis.xform(m_rbAFrame.basis.get_axis(2)); + Vector3 axisB = B->get_transform().basis.xform(m_rbBFrame.basis.get_axis(2)); + + const Vector3 &angVelA = A->get_angular_velocity(); + const Vector3 &angVelB = B->get_angular_velocity(); + + Vector3 angVelAroundHingeAxisA = axisA * axisA.dot(angVelA); + Vector3 angVelAroundHingeAxisB = axisB * axisB.dot(angVelB); + + Vector3 angAorthog = angVelA - angVelAroundHingeAxisA; + Vector3 angBorthog = angVelB - angVelAroundHingeAxisB; + Vector3 velrelOrthog = angAorthog - angBorthog; + { + //solve orthogonal angular velocity correction + real_t relaxation = real_t(1.); + real_t len = velrelOrthog.length(); + if (len > real_t(0.00001)) { + Vector3 normal = velrelOrthog.normalized(); + real_t denom = A->compute_angular_impulse_denominator(normal) + + B->compute_angular_impulse_denominator(normal); + // scale for mass and relaxation + velrelOrthog *= (real_t(1.) / denom) * m_relaxationFactor; + } + + //solve angular positional correction + Vector3 angularError = -axisA.cross(axisB) * (real_t(1.) / p_step); + real_t len2 = angularError.length(); + if (len2 > real_t(0.00001)) { + Vector3 normal2 = angularError.normalized(); + real_t denom2 = A->compute_angular_impulse_denominator(normal2) + + B->compute_angular_impulse_denominator(normal2); + angularError *= (real_t(1.) / denom2) * relaxation; + } + + A->apply_torque_impulse(-velrelOrthog + angularError); + B->apply_torque_impulse(velrelOrthog - angularError); + + // solve limit + if (m_solveLimit) { + real_t amplitude = ((angVelB - angVelA).dot(axisA) * m_relaxationFactor + m_correction * (real_t(1.) / p_step) * m_biasFactor) * m_limitSign; + + real_t impulseMag = amplitude * m_kHinge; + + // Clamp the accumulated impulse + real_t temp = m_accLimitImpulse; + m_accLimitImpulse = MAX(m_accLimitImpulse + impulseMag, real_t(0)); + impulseMag = m_accLimitImpulse - temp; + + Vector3 impulse = axisA * impulseMag * m_limitSign; + A->apply_torque_impulse(impulse); + B->apply_torque_impulse(-impulse); + } + } + + //apply motor + if (m_enableAngularMotor) { + //todo: add limits too + Vector3 angularLimit(0, 0, 0); + + Vector3 velrel = angVelAroundHingeAxisA - angVelAroundHingeAxisB; + real_t projRelVel = velrel.dot(axisA); + + real_t desiredMotorVel = m_motorTargetVelocity; + real_t motor_relvel = desiredMotorVel - projRelVel; + + real_t unclippedMotorImpulse = m_kHinge * motor_relvel; + //todo: should clip against accumulated impulse + real_t clippedMotorImpulse = unclippedMotorImpulse > m_maxMotorImpulse ? m_maxMotorImpulse : unclippedMotorImpulse; + clippedMotorImpulse = clippedMotorImpulse < -m_maxMotorImpulse ? -m_maxMotorImpulse : clippedMotorImpulse; + Vector3 motorImp = clippedMotorImpulse * axisA; + + A->apply_torque_impulse(motorImp + angularLimit); + B->apply_torque_impulse(-motorImp - angularLimit); + } + } +} +/* +void HingeJointSW::updateRHS(real_t timeStep) +{ + (void)timeStep; + +} +*/ + +static _FORCE_INLINE_ real_t atan2fast(real_t y, real_t x) { + real_t coeff_1 = Math_PI / 4.0f; + real_t coeff_2 = 3.0f * coeff_1; + real_t abs_y = Math::abs(y); + real_t angle; + if (x >= 0.0f) { + real_t r = (x - abs_y) / (x + abs_y); + angle = coeff_1 - coeff_1 * r; + } else { + real_t r = (x + abs_y) / (abs_y - x); + angle = coeff_2 - coeff_1 * r; + } + return (y < 0.0f) ? -angle : angle; +} + +real_t HingeJoint3DSW::get_hinge_angle() { + const Vector3 refAxis0 = A->get_transform().basis.xform(m_rbAFrame.basis.get_axis(0)); + const Vector3 refAxis1 = A->get_transform().basis.xform(m_rbAFrame.basis.get_axis(1)); + const Vector3 swingAxis = B->get_transform().basis.xform(m_rbBFrame.basis.get_axis(1)); + + return atan2fast(swingAxis.dot(refAxis0), swingAxis.dot(refAxis1)); +} + +void HingeJoint3DSW::set_param(PhysicsServer3D::HingeJointParam p_param, real_t p_value) { + + switch (p_param) { + + case PhysicsServer3D::HINGE_JOINT_BIAS: tau = p_value; break; + case PhysicsServer3D::HINGE_JOINT_LIMIT_UPPER: m_upperLimit = p_value; break; + case PhysicsServer3D::HINGE_JOINT_LIMIT_LOWER: m_lowerLimit = p_value; break; + case PhysicsServer3D::HINGE_JOINT_LIMIT_BIAS: m_biasFactor = p_value; break; + case PhysicsServer3D::HINGE_JOINT_LIMIT_SOFTNESS: m_limitSoftness = p_value; break; + case PhysicsServer3D::HINGE_JOINT_LIMIT_RELAXATION: m_relaxationFactor = p_value; break; + case PhysicsServer3D::HINGE_JOINT_MOTOR_TARGET_VELOCITY: m_motorTargetVelocity = p_value; break; + case PhysicsServer3D::HINGE_JOINT_MOTOR_MAX_IMPULSE: m_maxMotorImpulse = p_value; break; + case PhysicsServer3D::HINGE_JOINT_MAX: break; // Can't happen, but silences warning + } +} + +real_t HingeJoint3DSW::get_param(PhysicsServer3D::HingeJointParam p_param) const { + + switch (p_param) { + + case PhysicsServer3D::HINGE_JOINT_BIAS: return tau; + case PhysicsServer3D::HINGE_JOINT_LIMIT_UPPER: return m_upperLimit; + case PhysicsServer3D::HINGE_JOINT_LIMIT_LOWER: return m_lowerLimit; + case PhysicsServer3D::HINGE_JOINT_LIMIT_BIAS: return m_biasFactor; + case PhysicsServer3D::HINGE_JOINT_LIMIT_SOFTNESS: return m_limitSoftness; + case PhysicsServer3D::HINGE_JOINT_LIMIT_RELAXATION: return m_relaxationFactor; + case PhysicsServer3D::HINGE_JOINT_MOTOR_TARGET_VELOCITY: return m_motorTargetVelocity; + case PhysicsServer3D::HINGE_JOINT_MOTOR_MAX_IMPULSE: return m_maxMotorImpulse; + case PhysicsServer3D::HINGE_JOINT_MAX: break; // Can't happen, but silences warning + } + + return 0; +} + +void HingeJoint3DSW::set_flag(PhysicsServer3D::HingeJointFlag p_flag, bool p_value) { + + switch (p_flag) { + case PhysicsServer3D::HINGE_JOINT_FLAG_USE_LIMIT: m_useLimit = p_value; break; + case PhysicsServer3D::HINGE_JOINT_FLAG_ENABLE_MOTOR: m_enableAngularMotor = p_value; break; + case PhysicsServer3D::HINGE_JOINT_FLAG_MAX: break; // Can't happen, but silences warning + } +} +bool HingeJoint3DSW::get_flag(PhysicsServer3D::HingeJointFlag p_flag) const { + + switch (p_flag) { + case PhysicsServer3D::HINGE_JOINT_FLAG_USE_LIMIT: return m_useLimit; + case PhysicsServer3D::HINGE_JOINT_FLAG_ENABLE_MOTOR: return m_enableAngularMotor; + case PhysicsServer3D::HINGE_JOINT_FLAG_MAX: break; // Can't happen, but silences warning + } + + return false; +} |