redgpu/bullet: Bullet Physics SDK: real-time collision detection and multi-physics simulation for VR, games, visual effects, robotics, machine learning etc.

src/BulletInverseDynamics/MultiBodyTree.cpp
445 строк14 KB
Erwin Coumans
[InverseDynamics] Support for Jacobians & derivatives
26 авг 2016, 02:24
26 авг 2016, 02:24ba8964c
#include "MultiBodyTree.hpp"

#include <cmath>
#include <limits>
#include <vector>

#include "IDMath.hpp"
#include "details/MultiBodyTreeImpl.hpp"
#include "details/MultiBodyTreeInitCache.hpp"

namespace btInverseDynamics {

MultiBodyTree::MultiBodyTree()
	: m_is_finalized(false),
	  m_mass_parameters_are_valid(true),
	  m_accept_invalid_mass_parameters(false),
	  m_impl(0x0),
	  m_init_cache(0x0) {
	m_init_cache = new InitCache();
}

MultiBodyTree::~MultiBodyTree() {
	delete m_impl;
	delete m_init_cache;
}

void MultiBodyTree::setAcceptInvalidMassParameters(bool flag) {
	m_accept_invalid_mass_parameters = flag;
}

bool MultiBodyTree::getAcceptInvalidMassProperties() const {
	return m_accept_invalid_mass_parameters;
}

int MultiBodyTree::getBodyOrigin(const int body_index, vec3 *world_origin) const {
	return m_impl->getBodyOrigin(body_index, world_origin);
}

int MultiBodyTree::getBodyCoM(const int body_index, vec3 *world_com) const {
	return m_impl->getBodyCoM(body_index, world_com);
}

int MultiBodyTree::getBodyTransform(const int body_index, mat33 *world_T_body) const {
	return m_impl->getBodyTransform(body_index, world_T_body);
}
int MultiBodyTree::getBodyAngularVelocity(const int body_index, vec3 *world_omega) const {
	return m_impl->getBodyAngularVelocity(body_index, world_omega);
}
int MultiBodyTree::getBodyLinearVelocity(const int body_index, vec3 *world_velocity) const {
	return m_impl->getBodyLinearVelocity(body_index, world_velocity);
}

int MultiBodyTree::getBodyLinearVelocityCoM(const int body_index, vec3 *world_velocity) const {
	return m_impl->getBodyLinearVelocityCoM(body_index, world_velocity);
}

int MultiBodyTree::getBodyAngularAcceleration(const int body_index, vec3 *world_dot_omega) const {
	return m_impl->getBodyAngularAcceleration(body_index, world_dot_omega);
}
int MultiBodyTree::getBodyLinearAcceleration(const int body_index, vec3 *world_acceleration) const {
	return m_impl->getBodyLinearAcceleration(body_index, world_acceleration);
}

int MultiBodyTree::getParentRParentBodyRef(const int body_index, vec3* r) const {
    return m_impl->getParentRParentBodyRef(body_index, r);
}

int MultiBodyTree::getBodyTParentRef(const int body_index, mat33* T) const {
    return m_impl->getBodyTParentRef(body_index, T);
}

int MultiBodyTree::getBodyAxisOfMotion(const int body_index, vec3* axis) const {
    return m_impl->getBodyAxisOfMotion(body_index, axis);
}

void MultiBodyTree::printTree() { m_impl->printTree(); }
void MultiBodyTree::printTreeData() { m_impl->printTreeData(); }

int MultiBodyTree::numBodies() const { return m_impl->m_num_bodies; }

int MultiBodyTree::numDoFs() const { return m_impl->m_num_dofs; }

int MultiBodyTree::calculateInverseDynamics(const vecx &q, const vecx &u, const vecx &dot_u,
											vecx *joint_forces) {
	if (false == m_is_finalized) {
		error_message("system has not been initialized\n");
		return -1;
	}
	if (-1 == m_impl->calculateInverseDynamics(q, u, dot_u, joint_forces)) {
		error_message("error in inverse dynamics calculation\n");
		return -1;
	}
	return 0;
}

int MultiBodyTree::calculateMassMatrix(const vecx &q, const bool update_kinematics,
									   const bool initialize_matrix,
									   const bool set_lower_triangular_matrix, matxx *mass_matrix) {
	if (false == m_is_finalized) {
		error_message("system has not been initialized\n");
		return -1;
	}
	if (-1 ==
		m_impl->calculateMassMatrix(q, update_kinematics, initialize_matrix,
									set_lower_triangular_matrix, mass_matrix)) {
		error_message("error in mass matrix calculation\n");
		return -1;
	}
	return 0;
}

int MultiBodyTree::calculateMassMatrix(const vecx &q, matxx *mass_matrix) {
	return calculateMassMatrix(q, true, true, true, mass_matrix);
}



int MultiBodyTree::calculateKinematics(const vecx& q, const vecx& u, const vecx& dot_u) {
    vec3 world_gravity(m_impl->m_world_gravity);
    // temporarily set gravity to zero, to ensure we get the actual accelerations
    setZero(m_impl->m_world_gravity);

    if (false == m_is_finalized) {
        error_message("system has not been initialized\n");
        return -1;
    }
    if (-1 == m_impl->calculateKinematics(q, u, dot_u,
                                          MultiBodyTree::MultiBodyImpl::POSITION_VELOCITY_ACCELERATION)) {
        error_message("error in kinematics calculation\n");
        return -1;
    }

    m_impl->m_world_gravity=world_gravity;
    return 0;
}


int MultiBodyTree::calculatePositionKinematics(const vecx& q) {
	if (false == m_is_finalized) {
		error_message("system has not been initialized\n");
		return -1;
	}
	if (-1 == m_impl->calculateKinematics(q, q, q,
                                              MultiBodyTree::MultiBodyImpl::POSITION_VELOCITY)) {
		error_message("error in kinematics calculation\n");
		return -1;
	}
	return 0;
}

int MultiBodyTree::calculatePositionAndVelocityKinematics(const vecx& q, const vecx& u) {
	if (false == m_is_finalized) {
		error_message("system has not been initialized\n");
		return -1;
	}
	if (-1 == m_impl->calculateKinematics(q, u, u,
                                              MultiBodyTree::MultiBodyImpl::POSITION_VELOCITY)) {
		error_message("error in kinematics calculation\n");
		return -1;
	}
	return 0;
}


#if (defined BT_ID_HAVE_MAT3X) && (defined BT_ID_WITH_JACOBIANS)
int MultiBodyTree::calculateJacobians(const vecx& q, const vecx& u) {
    if (false == m_is_finalized) {
        error_message("system has not been initialized\n");
        return -1;
    }
    if (-1 == m_impl->calculateJacobians(q, u,
                                         MultiBodyTree::MultiBodyImpl::POSITION_VELOCITY)) {
        error_message("error in jacobian calculation\n");
        return -1;
    }
    return 0;
}

int MultiBodyTree::calculateJacobians(const vecx& q){
    if (false == m_is_finalized) {
        error_message("system has not been initialized\n");
        return -1;
    }
    if (-1 == m_impl->calculateJacobians(q, q,
                                         MultiBodyTree::MultiBodyImpl::POSITION_ONLY)) {
        error_message("error in jacobian calculation\n");
        return -1;
    }
    return 0;
}

int MultiBodyTree::getBodyDotJacobianTransU(const int body_index, vec3* world_dot_jac_trans_u) const {
    return m_impl->getBodyDotJacobianTransU(body_index,world_dot_jac_trans_u);
}

int MultiBodyTree::getBodyDotJacobianRotU(const int body_index, vec3* world_dot_jac_rot_u) const {
    return m_impl->getBodyDotJacobianRotU(body_index,world_dot_jac_rot_u);
}

int MultiBodyTree::getBodyJacobianTrans(const int body_index, mat3x* world_jac_trans) const {
    return m_impl->getBodyJacobianTrans(body_index,world_jac_trans);
}

int MultiBodyTree::getBodyJacobianRot(const int body_index, mat3x* world_jac_rot) const  {
    return m_impl->getBodyJacobianRot(body_index,world_jac_rot);
}


#endif

int MultiBodyTree::addBody(int body_index, int parent_index, JointType joint_type,
						   const vec3 &parent_r_parent_body_ref, const mat33 &body_T_parent_ref,
						   const vec3 &body_axis_of_motion_, idScalar mass,
						   const vec3 &body_r_body_com, const mat33 &body_I_body,
						   const int user_int, void *user_ptr) {
	if (body_index < 0) {
		error_message("body index must be positive (got %d)\n", body_index);
		return -1;
	}
	vec3 body_axis_of_motion(body_axis_of_motion_);
	switch (joint_type) {
		case REVOLUTE:
		case PRISMATIC:
			// check if axis is unit vector
			if (!isUnitVector(body_axis_of_motion)) {
				warning_message(
					"axis of motion not a unit axis ([%f %f %f]), will use normalized vector\n",
					body_axis_of_motion(0), body_axis_of_motion(1), body_axis_of_motion(2));
				idScalar length = std::sqrt(std::pow(body_axis_of_motion(0), 2) +
											std::pow(body_axis_of_motion(1), 2) +
											std::pow(body_axis_of_motion(2), 2));
				if (length < std::sqrt(std::numeric_limits<idScalar>::min())) {
					error_message("axis of motion vector too short (%e)\n", length);
					return -1;
				}
				body_axis_of_motion = (1.0 / length) * body_axis_of_motion;
			}
			break;
		case FIXED:
			break;
		case FLOATING:
			break;
		default:
			error_message("unknown joint type %d\n", joint_type);
			return -1;
	}

	// sanity check for mass properties. Zero mass is OK.
	if (mass < 0) {
		m_mass_parameters_are_valid = false;
		error_message("Body %d has invalid mass %e\n", body_index, mass);
		if (!m_accept_invalid_mass_parameters) {
			return -1;
		}
	}

	if (!isValidInertiaMatrix(body_I_body, body_index, FIXED == joint_type)) {
		m_mass_parameters_are_valid = false;
		// error message printed in function call
		if (!m_accept_invalid_mass_parameters) {
			return -1;
		}
	}

	if (!isValidTransformMatrix(body_T_parent_ref)) {
		return -1;
	}

	return m_init_cache->addBody(body_index, parent_index, joint_type, parent_r_parent_body_ref,
								 body_T_parent_ref, body_axis_of_motion, mass, body_r_body_com,
								 body_I_body, user_int, user_ptr);
}

int MultiBodyTree::getParentIndex(const int body_index, int *parent_index) const {
	return m_impl->getParentIndex(body_index, parent_index);
}

int MultiBodyTree::getUserInt(const int body_index, int *user_int) const {
	return m_impl->getUserInt(body_index, user_int);
}

int MultiBodyTree::getUserPtr(const int body_index, void **user_ptr) const {
	return m_impl->getUserPtr(body_index, user_ptr);
}

int MultiBodyTree::setUserInt(const int body_index, const int user_int) {
	return m_impl->setUserInt(body_index, user_int);
}

int MultiBodyTree::setUserPtr(const int body_index, void *const user_ptr) {
	return m_impl->setUserPtr(body_index, user_ptr);
}

int MultiBodyTree::finalize() {
	const int &num_bodies = m_init_cache->numBodies();
	const int &num_dofs = m_init_cache->numDoFs();

        if(num_dofs<=0) {
            error_message("Need num_dofs>=1, but num_dofs= %d\n", num_dofs);
            //return -1;
        }

	// 1 allocate internal MultiBody structure
	m_impl = new MultiBodyImpl(num_bodies, num_dofs);

	// 2 build new index set assuring index(parent) < index(child)
	if (-1 == m_init_cache->buildIndexSets()) {
		return -1;
	}
	m_init_cache->getParentIndexArray(&m_impl->m_parent_index);

	// 3 setup internal kinematic and dynamic data
	for (int index = 0; index < num_bodies; index++) {
		InertiaData inertia;
		JointData joint;
		if (-1 == m_init_cache->getInertiaData(index, &inertia)) {
			return -1;
		}
		if (-1 == m_init_cache->getJointData(index, &joint)) {
			return -1;
		}

		RigidBody &rigid_body = m_impl->m_body_list[index];

		rigid_body.m_mass = inertia.m_mass;
		rigid_body.m_body_mass_com = inertia.m_mass * inertia.m_body_pos_body_com;
		rigid_body.m_body_I_body = inertia.m_body_I_body;
		rigid_body.m_joint_type = joint.m_type;
		rigid_body.m_parent_pos_parent_body_ref = joint.m_parent_pos_parent_child_ref;
		rigid_body.m_body_T_parent_ref = joint.m_child_T_parent_ref;
		rigid_body.m_parent_pos_parent_body_ref = joint.m_parent_pos_parent_child_ref;
		rigid_body.m_joint_type = joint.m_type;

		// Set joint Jacobians. Note that the dimension is always 3x1 here to avoid variable sized
		// matrices.
		switch (rigid_body.m_joint_type) {
			case REVOLUTE:
				rigid_body.m_Jac_JR(0) = joint.m_child_axis_of_motion(0);
				rigid_body.m_Jac_JR(1) = joint.m_child_axis_of_motion(1);
				rigid_body.m_Jac_JR(2) = joint.m_child_axis_of_motion(2);
				rigid_body.m_Jac_JT(0) = 0.0;
				rigid_body.m_Jac_JT(1) = 0.0;
				rigid_body.m_Jac_JT(2) = 0.0;
				break;
			case PRISMATIC:
				rigid_body.m_Jac_JR(0) = 0.0;
				rigid_body.m_Jac_JR(1) = 0.0;
				rigid_body.m_Jac_JR(2) = 0.0;
				rigid_body.m_Jac_JT(0) = joint.m_child_axis_of_motion(0);
				rigid_body.m_Jac_JT(1) = joint.m_child_axis_of_motion(1);
				rigid_body.m_Jac_JT(2) = joint.m_child_axis_of_motion(2);
				break;
			case FIXED:
				// NOTE/TODO: dimension really should be zero ..
				rigid_body.m_Jac_JR(0) = 0.0;
				rigid_body.m_Jac_JR(1) = 0.0;
				rigid_body.m_Jac_JR(2) = 0.0;
				rigid_body.m_Jac_JT(0) = 0.0;
				rigid_body.m_Jac_JT(1) = 0.0;
				rigid_body.m_Jac_JT(2) = 0.0;
				break;
			case FLOATING:
				// NOTE/TODO: this is not really correct.
				// the Jacobians should be 3x3 matrices here !
				rigid_body.m_Jac_JR(0) = 0.0;
				rigid_body.m_Jac_JR(1) = 0.0;
				rigid_body.m_Jac_JR(2) = 0.0;
				rigid_body.m_Jac_JT(0) = 0.0;
				rigid_body.m_Jac_JT(1) = 0.0;
				rigid_body.m_Jac_JT(2) = 0.0;
				break;
			default:
				error_message("unsupported joint type %d\n", rigid_body.m_joint_type);
				return -1;
		}
	}

	// 4 assign degree of freedom indices & build per-joint-type index arrays
	if (-1 == m_impl->generateIndexSets()) {
		error_message("generating index sets\n");
		return -1;
	}

	// 5 do some pre-computations ..
	m_impl->calculateStaticData();

	// 6. make sure all user forces are set to zero, as this might not happen
	//	in the vector ctors.
	m_impl->clearAllUserForcesAndMoments();

	m_is_finalized = true;
	return 0;
}

int MultiBodyTree::setGravityInWorldFrame(const vec3 &gravity) {
	return m_impl->setGravityInWorldFrame(gravity);
}

int MultiBodyTree::getJointType(const int body_index, JointType *joint_type) const {
	return m_impl->getJointType(body_index, joint_type);
}

int MultiBodyTree::getJointTypeStr(const int body_index, const char **joint_type) const {
	return m_impl->getJointTypeStr(body_index, joint_type);
}

int MultiBodyTree::getDoFOffset(const int body_index, int *q_offset) const {
	return m_impl->getDoFOffset(body_index, q_offset);
}

int MultiBodyTree::setBodyMass(const int body_index, idScalar mass) {
	return m_impl->setBodyMass(body_index, mass);
}

int MultiBodyTree::setBodyFirstMassMoment(const int body_index, const vec3& first_mass_moment) {
	return m_impl->setBodyFirstMassMoment(body_index, first_mass_moment);
}

int MultiBodyTree::setBodySecondMassMoment(const int body_index, const mat33& second_mass_moment) {
	return m_impl->setBodySecondMassMoment(body_index, second_mass_moment);
}

int MultiBodyTree::getBodyMass(const int body_index, idScalar *mass) const {
	return m_impl->getBodyMass(body_index, mass);
}

int MultiBodyTree::getBodyFirstMassMoment(const int body_index, vec3 *first_mass_moment) const {
	return m_impl->getBodyFirstMassMoment(body_index, first_mass_moment);
}

int MultiBodyTree::getBodySecondMassMoment(const int body_index, mat33 *second_mass_moment) const {
	return m_impl->getBodySecondMassMoment(body_index, second_mass_moment);
}

void MultiBodyTree::clearAllUserForcesAndMoments() { m_impl->clearAllUserForcesAndMoments(); }

int MultiBodyTree::addUserForce(const int body_index, const vec3 &body_force) {
	return m_impl->addUserForce(body_index, body_force);
}

int MultiBodyTree::addUserMoment(const int body_index, const vec3 &body_moment) {
	return m_impl->addUserMoment(body_index, body_moment);
}

}