Taylor Howell
52ed96bc3a
PiperOrigin-RevId: 875087590 Change-Id: I1a5489d2d2011795ee38b09d547e68acd72e3cc7
1551 lines
45 KiB
C
1551 lines
45 KiB
C
// Copyright 2021 DeepMind Technologies Limited
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include "engine/engine_forward.h"
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#include <stddef.h>
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#include <stdio.h>
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#include <mujoco/mjdata.h>
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#include <mujoco/mjmacro.h>
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#include <mujoco/mjmodel.h>
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#include <mujoco/mjsan.h> // IWYU pragma: keep
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#include <mujoco/mjplugin.h>
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#include "engine/engine_callback.h"
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#include "engine/engine_collision_driver.h"
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#include "engine/engine_core_constraint.h"
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#include "engine/engine_core_smooth.h"
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#include "engine/engine_derivative.h"
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#include "engine/engine_core_util.h"
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#include "engine/engine_inverse.h"
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#include "engine/engine_island.h"
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#include "engine/engine_macro.h"
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#include "engine/engine_memory.h"
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#include "engine/engine_passive.h"
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#include "engine/engine_plugin.h"
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#include "engine/engine_sensor.h"
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#include "engine/engine_sleep.h"
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#include "engine/engine_solver.h"
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#include "engine/engine_support.h"
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#include "engine/engine_util_blas.h"
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#include "engine/engine_util_errmem.h"
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#include "engine/engine_util_misc.h"
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#include "engine/engine_util_solve.h"
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#include "engine/engine_util_sparse.h"
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#include "thread/thread_pool.h"
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#include "thread/thread_task.h"
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//--------------------------- check values ---------------------------------------------------------
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// check positions, reset if bad
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void mj_checkPos(const mjModel* m, mjData* d) {
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int nq = m->nq;
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const mjtNum* qpos = d->qpos;
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for (int i=0; i < nq; i++) {
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if (mju_isBad(qpos[i])) {
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mj_warning(d, mjWARN_BADQPOS, i);
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if (!mjDISABLED(mjDSBL_AUTORESET)) {
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mj_resetData(m, d);
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}
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d->warning[mjWARN_BADQPOS].number++;
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d->warning[mjWARN_BADQPOS].lastinfo = i;
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return;
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}
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}
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}
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// check velocities, reset if bad
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void mj_checkVel(const mjModel* m, mjData* d) {
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int sleep_filter = mjENABLED(mjENBL_SLEEP) && d->nv_awake < m->nv;
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int nv = sleep_filter ? d->nv_awake : m->nv;
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for (int j=0; j < nv; j++) {
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int i = sleep_filter ? d->dof_awake_ind[j] : j;
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if (mju_isBad(d->qvel[i])) {
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mj_warning(d, mjWARN_BADQVEL, i);
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if (!mjDISABLED(mjDSBL_AUTORESET)) {
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mj_resetData(m, d);
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}
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d->warning[mjWARN_BADQVEL].number++;
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d->warning[mjWARN_BADQVEL].lastinfo = i;
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return;
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}
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}
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}
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// check accelerations, reset if bad
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void mj_checkAcc(const mjModel* m, mjData* d) {
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int sleep_filter = mjENABLED(mjENBL_SLEEP) && d->nv_awake < m->nv;
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int nv = sleep_filter ? d->nv_awake : m->nv;
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for (int j=0; j < nv; j++) {
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int i = sleep_filter ? d->dof_awake_ind[j] : j;
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if (mju_isBad(d->qacc[i])) {
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mj_warning(d, mjWARN_BADQACC, i);
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if (!mjDISABLED(mjDSBL_AUTORESET)) {
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mj_resetData(m, d);
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}
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d->warning[mjWARN_BADQACC].number++;
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d->warning[mjWARN_BADQACC].lastinfo = i;
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if (!mjDISABLED(mjDSBL_AUTORESET)) {
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mj_forward(m, d);
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}
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return;
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}
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}
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}
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//-------------------------- solver components -----------------------------------------------------
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// args for internal functions in mj_fwdPosition
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struct mjFwdPositionArgs_ {
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const mjModel* m;
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mjData* d;
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};
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typedef struct mjFwdPositionArgs_ mjFwdPositionArgs;
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// wrapper for mj_crb and mj_factorM
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void* mj_inertialThreaded(void* args) {
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mjFwdPositionArgs* forward_args = (mjFwdPositionArgs*) args;
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mj_makeM(forward_args->m, forward_args->d);
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mj_factorM(forward_args->m, forward_args->d);
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return NULL;
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}
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// wrapper for mj_collision
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void* mj_collisionThreaded(void* args) {
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mjFwdPositionArgs* forward_args = (mjFwdPositionArgs*) args;
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mj_collision(forward_args->m, forward_args->d);
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return NULL;
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}
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// kinematics-related computations
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void mj_fwdKinematics(const mjModel* m, mjData* d) {
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mj_kinematics(m, d);
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mj_comPos(m, d);
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mj_camlight(m, d);
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mj_flex(m, d);
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mj_tendon(m, d);
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if (mj_wakeTendon(m, d)) {
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mj_updateSleep(m, d);
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}
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}
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// position-dependent computations
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void mj_fwdPosition(const mjModel* m, mjData* d) {
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TM_START1;
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// clear position-dependent flags for lazy evaluation
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d->flg_energypos = 0;
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TM_START;
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mj_fwdKinematics(m, d);
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TM_END(mjTIMER_POS_KINEMATICS);
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// no threadpool: inertia and collision on main thread
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if (!d->threadpool) {
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// inertia, timed internally (POS_INERTIA)
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mj_makeM(m, d);
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mj_factorM(m, d);
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// collision, timed internally (POS_COLLISION)
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mj_collision(m, d);
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}
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// have threadpool: inertia and collision on separate threads
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else {
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mjTask tasks[2];
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mjFwdPositionArgs forward_args;
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forward_args.m = m;
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forward_args.d = d;
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mju_defaultTask(&tasks[0]);
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tasks[0].func = mj_inertialThreaded;
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tasks[0].args = &forward_args;
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mju_threadPoolEnqueue((mjThreadPool*)d->threadpool, &tasks[0]);
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mju_defaultTask(&tasks[1]);
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tasks[1].func = mj_collisionThreaded;
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tasks[1].args = &forward_args;
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mju_threadPoolEnqueue((mjThreadPool*)d->threadpool, &tasks[1]);
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mju_taskJoin(&tasks[0]);
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mju_taskJoin(&tasks[1]);
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}
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if (mj_wakeCollision(m, d)) {
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mj_updateSleep(m, d);
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mj_collision(m, d);
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}
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if (mj_wakeEquality(m, d)) {
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mj_updateSleep(m, d);
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}
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TM_RESTART;
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mj_makeConstraint(m, d);
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mj_island(m, d);
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TM_END(mjTIMER_POS_MAKE);
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TM_RESTART;
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mj_transmission(m, d);
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TM_ADD(mjTIMER_POS_KINEMATICS);
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TM_RESTART;
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mj_projectConstraint(m, d);
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TM_END(mjTIMER_POS_PROJECT);
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TM_END1(mjTIMER_POSITION);
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}
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// velocity-dependent computations
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void mj_fwdVelocity(const mjModel* m, mjData* d) {
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TM_START;
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// clear velocity-dependent flags for lazy evaluation
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d->flg_subtreevel = 0;
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d->flg_energyvel = 0;
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// flexedge velocity: always sparse
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mju_mulMatVecSparse(d->flexedge_velocity, d->flexedge_J, d->qvel, m->nflexedge,
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m->flexedge_J_rownnz, m->flexedge_J_rowadr, m->flexedge_J_colind, NULL);
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// tendon velocity: always sparse
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mju_mulMatVecSparse(d->ten_velocity, d->ten_J, d->qvel, m->ntendon,
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m->ten_J_rownnz, m->ten_J_rowadr, m->ten_J_colind, NULL);
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// actuator velocity: always sparse
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if (!mjDISABLED(mjDSBL_ACTUATION)) {
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mju_mulMatVecSparse(d->actuator_velocity, d->actuator_moment, d->qvel, m->nu,
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d->moment_rownnz, d->moment_rowadr, d->moment_colind, NULL);
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} else {
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mju_zero(d->actuator_velocity, m->nu);
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}
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// com-based velocities, passive forces, constraint references
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mj_comVel(m, d);
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mj_passive(m, d);
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mj_referenceConstraint(m, d);
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// compute qfrc_bias with abbreviated RNE (without acceleration)
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mj_rne(m, d, 0, d->qfrc_bias);
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// add bias force due to tendon armature
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mj_tendonBias(m, d, d->qfrc_bias);
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TM_END(mjTIMER_VELOCITY);
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}
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// clamp vector to range
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static void clampVec(mjtNum* vec, const mjtNum* range, const mjtByte* limited, int n,
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const int* index) {
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for (int i=0; i < n; i++) {
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int j = index ? index[i] : i;
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if (limited[i]) {
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vec[j] = mju_clip(vec[j], range[2*i], range[2*i + 1]);
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}
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}
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}
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// (qpos, qvel, ctrl, act) => (qfrc_actuator, actuator_force, act_dot)
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void mj_fwdActuation(const mjModel* m, mjData* d) {
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TM_START;
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int nv = m->nv, nu = m->nu, ntendon = m->ntendon;
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mjtNum gain, bias, tau;
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mjtNum *prm, *force = d->actuator_force;
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// clear actuator_force
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mju_zero(force, nu);
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int sleep_filter = mjENABLED(mjENBL_SLEEP);
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// disabled or no actuation: return
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if (nu == 0 || mjDISABLED(mjDSBL_ACTUATION)) {
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mju_zero(d->qfrc_actuator, nv);
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return;
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}
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// any tendon transmission targets with force limits
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int tendon_frclimited = 0;
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// local copy of ctrl
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mj_markStack(d);
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mjtNum *ctrl = mjSTACKALLOC(d, nu, mjtNum);
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// read from ctrl or history buffer for delayed actuators
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for (int i = 0; i < nu; i++) {
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int interp = m->actuator_history[2*i+1];
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ctrl[i] = m->actuator_delay[i] ? mj_readCtrl(m, d, i, d->time, interp) : d->ctrl[i];
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}
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// clamp local copy
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if (!mjDISABLED(mjDSBL_CLAMPCTRL)) {
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clampVec(ctrl, m->actuator_ctrlrange, m->actuator_ctrllimited, nu, NULL);
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}
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// check controls, set all to 0 if any are bad
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for (int i=0; i < nu; i++) {
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if (mju_isBad(ctrl[i])) {
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mj_warning(d, mjWARN_BADCTRL, i);
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mju_zero(ctrl, nu);
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break;
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}
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}
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// act_dot for stateful actuators
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for (int i=0; i < nu; i++) {
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if (sleep_filter && mj_sleepState(m, d, mjOBJ_ACTUATOR, i) == mjS_ASLEEP) {
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continue;
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}
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int act_first = m->actuator_actadr[i];
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if (act_first < 0) {
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continue;
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}
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// zero act_dot for actuator plugins
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if (m->actuator_actnum[i]) {
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mju_zero(d->act_dot + act_first, m->actuator_actnum[i]);
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}
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// extract info
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prm = m->actuator_dynprm + i*mjNDYN;
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// index into the last element in act. For most actuators it's also the
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// first element, but actuator plugins might store their own state in act.
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int act_last = act_first + m->actuator_actnum[i] - 1;
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// compute act_dot according to dynamics type
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switch ((mjtDyn) m->actuator_dyntype[i]) {
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case mjDYN_INTEGRATOR: // simple integrator
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d->act_dot[act_last] = ctrl[i];
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break;
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case mjDYN_FILTER: // linear filter: prm = tau
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case mjDYN_FILTEREXACT:
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tau = mju_max(mjMINVAL, prm[0]);
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d->act_dot[act_last] = (ctrl[i] - d->act[act_last]) / tau;
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break;
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case mjDYN_MUSCLE: // muscle model: prm = (tau_act, tau_deact)
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d->act_dot[act_last] = mju_muscleDynamics(
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ctrl[i], d->act[act_last], prm);
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break;
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default: // user dynamics
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if (mjcb_act_dyn) {
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if (m->actuator_actnum[i] == 1) {
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// scalar activation dynamics, get act_dot
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d->act_dot[act_last] = mjcb_act_dyn(m, d, i);
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} else {
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// higher-order dynamics, mjcb_act_dyn writes into act_dot directly
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mjcb_act_dyn(m, d, i);
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}
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}
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}
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}
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// get act_dot from actuator plugins
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if (m->nplugin) {
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const int nslot = mjp_pluginCount();
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for (int i=0; i < m->nplugin; i++) {
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const int slot = m->plugin[i];
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const mjpPlugin* plugin = mjp_getPluginAtSlotUnsafe(slot, nslot);
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if (!plugin) {
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mjERROR("invalid plugin slot: %d", slot);
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}
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if (plugin->capabilityflags & mjPLUGIN_ACTUATOR) {
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if (plugin->actuator_act_dot) {
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plugin->actuator_act_dot(m, d, i);
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}
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}
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}
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}
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// force = gain .* [ctrl/act] + bias
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for (int i=0; i < nu; i++) {
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// skip if sleeping
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if (sleep_filter && mj_sleepState(m, d, mjOBJ_ACTUATOR, i) == mjS_ASLEEP) {
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continue;
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}
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// skip if disabled
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if (mj_actuatorDisabled(m, i)) {
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continue;
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}
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// skip actuator plugins -- these are handled after builtin actuator types
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if (m->actuator_plugin[i] >= 0) {
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continue;
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}
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// check for tendon transmission with force limits
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if (ntendon && !tendon_frclimited && m->actuator_trntype[i] == mjTRN_TENDON) {
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tendon_frclimited = m->tendon_actfrclimited[m->actuator_trnid[2*i]];
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}
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// extract gain info
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prm = m->actuator_gainprm + mjNGAIN*i;
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// handle according to gain type
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switch ((mjtGain) m->actuator_gaintype[i]) {
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case mjGAIN_FIXED: // fixed gain: prm = gain
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gain = prm[0];
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break;
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case mjGAIN_AFFINE: // affine: prm = [const, kp, kv]
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gain = prm[0] + prm[1]*d->actuator_length[i] + prm[2]*d->actuator_velocity[i];
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break;
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case mjGAIN_MUSCLE: // muscle gain
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gain = mju_muscleGain(d->actuator_length[i],
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d->actuator_velocity[i],
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m->actuator_lengthrange+2*i,
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m->actuator_acc0[i],
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prm);
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break;
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default: // user gain
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if (mjcb_act_gain) {
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gain = mjcb_act_gain(m, d, i);
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} else {
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gain = 1;
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}
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}
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// set force = gain .* [ctrl/act]
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if (m->actuator_actadr[i] == -1) {
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force[i] = gain * ctrl[i];
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} else {
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// use last activation variable associated with actuator i
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int act_adr = m->actuator_actadr[i] + m->actuator_actnum[i] - 1;
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mjtNum act;
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if (m->actuator_actearly[i]) {
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act = mj_nextActivation(m, d, i, act_adr, d->act_dot[act_adr]);
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} else {
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act = d->act[act_adr];
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}
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force[i] = gain * act;
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}
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// extract bias info
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prm = m->actuator_biasprm + mjNBIAS*i;
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// handle according to bias type
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switch ((mjtBias) m->actuator_biastype[i]) {
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case mjBIAS_NONE: // none
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bias = 0.0;
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break;
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case mjBIAS_AFFINE: // affine: prm = [const, kp, kv]
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bias = prm[0] + prm[1]*d->actuator_length[i] + prm[2]*d->actuator_velocity[i];
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break;
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case mjBIAS_MUSCLE: // muscle passive force
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bias = mju_muscleBias(d->actuator_length[i],
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m->actuator_lengthrange+2*i,
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m->actuator_acc0[i],
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prm);
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break;
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default: // user bias
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if (mjcb_act_bias) {
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bias = mjcb_act_bias(m, d, i);
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} else {
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bias = 0;
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}
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}
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// add bias
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force[i] += bias;
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}
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|
|
|
// handle actuator plugins
|
|
if (m->nplugin) {
|
|
const int nslot = mjp_pluginCount();
|
|
for (int i=0; i < m->nplugin; i++) {
|
|
const int slot = m->plugin[i];
|
|
const mjpPlugin* plugin = mjp_getPluginAtSlotUnsafe(slot, nslot);
|
|
if (!plugin) {
|
|
mjERROR("invalid plugin slot: %d", slot);
|
|
}
|
|
if (plugin->capabilityflags & mjPLUGIN_ACTUATOR) {
|
|
if (!plugin->compute) {
|
|
mjERROR("`compute` is a null function pointer for plugin at slot %d", slot);
|
|
}
|
|
plugin->compute(m, d, i, mjPLUGIN_ACTUATOR);
|
|
}
|
|
}
|
|
}
|
|
|
|
// clamp tendon total actuator force
|
|
if (tendon_frclimited) {
|
|
// compute total force for each tendon
|
|
mjtNum* tendon_total_force = mjSTACKALLOC(d, ntendon, mjtNum);
|
|
mju_zero(tendon_total_force, ntendon);
|
|
for (int i=0; i < nu; i++) {
|
|
if (m->actuator_trntype[i] == mjTRN_TENDON) {
|
|
int tendon_id = m->actuator_trnid[2*i];
|
|
if (m->tendon_actfrclimited[tendon_id]) {
|
|
tendon_total_force[tendon_id] += force[i];
|
|
}
|
|
}
|
|
}
|
|
|
|
// scale tendon actuator forces if limited and outside range
|
|
for (int i=0; i < nu; i++) {
|
|
if (m->actuator_trntype[i] != mjTRN_TENDON) {
|
|
continue;
|
|
}
|
|
int tendon_id = m->actuator_trnid[2*i];
|
|
mjtNum tendon_force = tendon_total_force[tendon_id];
|
|
if (m->tendon_actfrclimited[tendon_id] && tendon_force) {
|
|
const mjtNum* range = m->tendon_actfrcrange + 2 * tendon_id;
|
|
if (tendon_force < range[0]) {
|
|
force[i] *= range[0] / tendon_force;
|
|
} else if (tendon_force > range[1]) {
|
|
force[i] *= range[1] / tendon_force;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// clamp actuator_force
|
|
clampVec(force, m->actuator_forcerange, m->actuator_forcelimited, nu, NULL);
|
|
|
|
// qfrc_actuator = moment' * force
|
|
mju_mulMatTVecSparse(d->qfrc_actuator, d->actuator_moment, force, nu, nv,
|
|
d->moment_rownnz, d->moment_rowadr, d->moment_colind);
|
|
|
|
// actuator-level gravity compensation
|
|
if (m->ngravcomp && !mjDISABLED(mjDSBL_GRAVITY) && mju_norm3(m->opt.gravity)) {
|
|
// number of dofs for each joint type: {mjJNT_FREE, mjJNT_BALL, mjJNT_SLIDE, mjJNT_HINGE}
|
|
static const int jnt_dofnum[4] = {6, 3, 1, 1};
|
|
int njnt = m->njnt;
|
|
for (int i=0; i < njnt; i++) {
|
|
// skip if gravcomp added as passive force
|
|
if (!m->jnt_actgravcomp[i]) {
|
|
continue;
|
|
}
|
|
|
|
// add gravcomp force
|
|
int dofnum = jnt_dofnum[m->jnt_type[i]];
|
|
int dofadr = m->jnt_dofadr[i];
|
|
mju_addTo(d->qfrc_actuator + dofadr, d->qfrc_gravcomp + dofadr, dofnum);
|
|
}
|
|
}
|
|
|
|
// clamp qfrc_actuator to joint-level actuator force limits
|
|
clampVec(d->qfrc_actuator, m->jnt_actfrcrange, m->jnt_actfrclimited, m->njnt, m->jnt_dofadr);
|
|
|
|
mj_freeStack(d);
|
|
TM_END(mjTIMER_ACTUATION);
|
|
}
|
|
|
|
|
|
// add up all non-constraint forces, compute qacc_smooth
|
|
void mj_fwdAcceleration(const mjModel* m, mjData* d) {
|
|
int sleep_filter = mjENABLED(mjENBL_SLEEP) && d->nv_awake < m->nv;
|
|
int nv;
|
|
const int* index;
|
|
|
|
// qfrc_smooth = qfrc_passive - qfrc_bias + qfrc_applied + qfrc_actuator
|
|
if (!sleep_filter) {
|
|
nv = m->nv;
|
|
index = NULL;
|
|
mju_sub(d->qfrc_smooth, d->qfrc_passive, d->qfrc_bias, nv);
|
|
mju_addTo(d->qfrc_smooth, d->qfrc_applied, nv);
|
|
mju_addTo(d->qfrc_smooth, d->qfrc_actuator, nv);
|
|
} else {
|
|
nv = d->nv_awake;
|
|
index = d->dof_awake_ind;
|
|
mju_subInd(d->qfrc_smooth, d->qfrc_passive, d->qfrc_bias, index, nv);
|
|
mju_addToInd(d->qfrc_smooth, d->qfrc_applied, index, nv);
|
|
mju_addToInd(d->qfrc_smooth, d->qfrc_actuator, index, nv);
|
|
}
|
|
|
|
// qfrc_smooth += project(xfrc_applied)
|
|
mj_xfrcAccumulate(m, d, d->qfrc_smooth);
|
|
|
|
// copy for in-place solve: qacc_smooth = qfrc_smooth
|
|
if (!sleep_filter) {
|
|
mju_copy(d->qacc_smooth, d->qfrc_smooth, nv);
|
|
} else {
|
|
mju_copyInd(d->qacc_smooth, d->qfrc_smooth, index, nv);
|
|
}
|
|
|
|
// qacc_smooth = M \ qfrc_smooth
|
|
mj_solveLD(d->qacc_smooth, d->qLD, d->qLDiagInv, nv, 1,
|
|
m->M_rownnz, m->M_rowadr, m->M_colind, index);
|
|
}
|
|
|
|
|
|
// warmstart/init solver
|
|
static void warmstart(const mjModel* m, mjData* d) {
|
|
int nv = m->nv, nefc = d->nefc;
|
|
|
|
// warmstart with best of (qacc_warmstart, qacc_smooth)
|
|
if (!mjDISABLED(mjDSBL_WARMSTART)) {
|
|
mj_markStack(d);
|
|
mjtNum* jar = mjSTACKALLOC(d, nefc, mjtNum);
|
|
|
|
// start with qacc = qacc_warmstart
|
|
mju_copy(d->qacc, d->qacc_warmstart, nv);
|
|
|
|
// compute jar(qacc_warmstart)
|
|
mj_mulJacVec(m, d, jar, d->qacc_warmstart);
|
|
mju_subFrom(jar, d->efc_aref, nefc);
|
|
|
|
// update constraints, save cost(qacc_warmstart)
|
|
mjtNum cost_warmstart;
|
|
mj_constraintUpdate(m, d, jar, &cost_warmstart, 0);
|
|
|
|
// PGS
|
|
if (m->opt.solver == mjSOL_PGS) {
|
|
// cost(force_warmstart)
|
|
mjtNum PGS_warmstart = mju_dot(d->efc_force, d->efc_b, nefc);
|
|
mjtNum* ARf = mjSTACKALLOC(d, nefc, mjtNum);
|
|
if (mj_isSparse(m))
|
|
mju_mulMatVecSparse(ARf, d->efc_AR, d->efc_force, nefc,
|
|
d->efc_AR_rownnz, d->efc_AR_rowadr,
|
|
d->efc_AR_colind, NULL);
|
|
else {
|
|
mju_mulMatVec(ARf, d->efc_AR, d->efc_force, nefc, nefc);
|
|
}
|
|
PGS_warmstart += 0.5*mju_dot(d->efc_force, ARf, nefc);
|
|
|
|
// use zero if better
|
|
if (PGS_warmstart > 0) {
|
|
mju_zero(d->efc_force, nefc);
|
|
mju_zero(d->qfrc_constraint, nv);
|
|
}
|
|
}
|
|
|
|
// non-PGS
|
|
else {
|
|
// add Gauss to cost(qacc_warmstart)
|
|
mjtNum* Ma = mjSTACKALLOC(d, nv, mjtNum);
|
|
mj_mulM(m, d, Ma, d->qacc_warmstart);
|
|
for (int i=0; i < nv; i++) {
|
|
cost_warmstart += 0.5*(Ma[i]-d->qfrc_smooth[i])*(d->qacc_warmstart[i]-d->qacc_smooth[i]);
|
|
}
|
|
|
|
// cost(qacc_smooth)
|
|
mjtNum cost_smooth;
|
|
mj_constraintUpdate(m, d, d->efc_b, &cost_smooth, 0);
|
|
|
|
// use qacc_smooth if better
|
|
if (cost_warmstart > cost_smooth) {
|
|
mju_copy(d->qacc, d->qacc_smooth, nv);
|
|
}
|
|
}
|
|
|
|
// have island structure: unconstrained qacc = qacc_smooth
|
|
if (d->nisland > 0) {
|
|
// loop over unconstrained dofs in map_idof2dof[nidof, nv)
|
|
for (int i=d->nidof; i < nv; i++) {
|
|
int dof = d->map_idof2dof[i];
|
|
d->qacc[dof] = d->qacc_smooth[dof];
|
|
}
|
|
}
|
|
|
|
mj_freeStack(d);
|
|
}
|
|
|
|
// coldstart with qacc = qacc_smooth, efc_force = 0
|
|
else {
|
|
mju_copy(d->qacc, d->qacc_smooth, nv);
|
|
mju_zero(d->efc_force, nefc);
|
|
}
|
|
}
|
|
|
|
|
|
// struct encapsulating arguments to thread task
|
|
struct mjSolIslandArgs_ {
|
|
const mjModel* m;
|
|
mjData* d;
|
|
int island;
|
|
};
|
|
typedef struct mjSolIslandArgs_ mjSolIslandArgs;
|
|
|
|
// extract arguments, pass to CG solver
|
|
static void* CG_wrapper(void* args) {
|
|
mjSolIslandArgs* solargs = (mjSolIslandArgs*) args;
|
|
mj_solCG_island(solargs->m, solargs->d, solargs->island, solargs->m->opt.iterations);
|
|
return NULL;
|
|
}
|
|
|
|
// extract arguments, pass to Newton solver
|
|
static void* Newton_wrapper(void* args) {
|
|
mjSolIslandArgs* solargs = (mjSolIslandArgs*) args;
|
|
mj_solNewton_island(solargs->m, solargs->d, solargs->island, solargs->m->opt.iterations);
|
|
return NULL;
|
|
}
|
|
|
|
// CG solver, multi-threaded over islands
|
|
static void solve_threaded(const mjModel* m, mjData* d, int flg_Newton) {
|
|
mj_markStack(d);
|
|
// allocate array of arguments to be passed to threads
|
|
mjSolIslandArgs* sol_island_args = mjSTACKALLOC(d, d->nisland, mjSolIslandArgs);
|
|
mjTask* tasks = mjSTACKALLOC(d, d->nisland, mjTask);
|
|
|
|
for (int island = 0; island < d->nisland; ++island) {
|
|
sol_island_args[island].m = m;
|
|
sol_island_args[island].d = d;
|
|
sol_island_args[island].island = island;
|
|
|
|
mju_defaultTask(&tasks[island]);
|
|
tasks[island].func = flg_Newton ? Newton_wrapper : CG_wrapper;
|
|
tasks[island].args = &sol_island_args[island];
|
|
mju_threadPoolEnqueue((mjThreadPool*)d->threadpool, &tasks[island]);
|
|
}
|
|
|
|
for (int island = 0; island < d->nisland; ++island) {
|
|
mju_taskJoin(&tasks[island]);
|
|
}
|
|
|
|
mj_freeStack(d);
|
|
}
|
|
|
|
|
|
// compute efc_b, efc_force, qfrc_constraint; update qacc
|
|
void mj_fwdConstraint(const mjModel* m, mjData* d) {
|
|
TM_START;
|
|
int nv = m->nv, nefc = d->nefc, nisland = d->nisland;
|
|
|
|
// always clear qfrc_constraint
|
|
mju_zero(d->qfrc_constraint, nv);
|
|
|
|
// no constraints: copy unconstrained acc, clear forces, return
|
|
if (!nefc) {
|
|
mju_copy(d->qacc, d->qacc_smooth, nv);
|
|
mju_zeroInt(d->solver_niter, mjNISLAND);
|
|
TM_END(mjTIMER_CONSTRAINT);
|
|
return;
|
|
}
|
|
|
|
// compute efc_b = J*qacc_smooth - aref
|
|
mj_mulJacVec(m, d, d->efc_b, d->qacc_smooth);
|
|
mju_subFrom(d->efc_b, d->efc_aref, nefc);
|
|
|
|
// warmstart solver
|
|
warmstart(m, d);
|
|
mju_zeroInt(d->solver_niter, mjNISLAND);
|
|
|
|
// check if islands are supported
|
|
int islands_supported = !mjDISABLED(mjDSBL_ISLAND) &&
|
|
nisland > 0 &&
|
|
m->opt.noslip_iterations == 0 &&
|
|
(m->opt.solver == mjSOL_CG || m->opt.solver == mjSOL_NEWTON);
|
|
|
|
// run solver over constraint islands
|
|
if (islands_supported) {
|
|
int nidof = d->nidof;
|
|
|
|
// copy inputs to islands (vel+acc deps, pos-dependent already copied in mj_island)
|
|
mju_gather(d->ifrc_smooth, d->qfrc_smooth, d->map_idof2dof, nidof);
|
|
mju_gather(d->ifrc_constraint, d->qfrc_constraint, d->map_idof2dof, nidof);
|
|
mju_gather(d->iacc_smooth, d->qacc_smooth, d->map_idof2dof, nidof);
|
|
mju_gather(d->iacc, d->qacc, d->map_idof2dof, nidof);
|
|
mju_gather(d->iefc_force, d->efc_force, d->map_iefc2efc, nefc);
|
|
mju_gather(d->iefc_aref, d->efc_aref, d->map_iefc2efc, nefc);
|
|
|
|
// solve per island, with or without threads
|
|
if (!d->threadpool) {
|
|
// no threadpool, loop over islands
|
|
for (int island=0; island < nisland; island++) {
|
|
if (m->opt.solver == mjSOL_NEWTON) {
|
|
mj_solNewton_island(m, d, island, m->opt.iterations);
|
|
} else {
|
|
mj_solCG_island(m, d, island, m->opt.iterations);
|
|
}
|
|
}
|
|
} else {
|
|
// have threadpool, solve using threads
|
|
solve_threaded(m, d, m->opt.solver == mjSOL_NEWTON);
|
|
}
|
|
|
|
// copy back solver outputs (scatter dofs since ni <= nv)
|
|
mju_scatter(d->qacc, d->iacc, d->map_idof2dof, nidof);
|
|
mju_scatter(d->qfrc_constraint, d->ifrc_constraint, d->map_idof2dof, nidof);
|
|
mju_gather(d->efc_force, d->iefc_force, d->map_efc2iefc, nefc);
|
|
}
|
|
|
|
// run solver over all constraints
|
|
else {
|
|
switch ((mjtSolver) m->opt.solver) {
|
|
case mjSOL_PGS: // PGS
|
|
mj_solPGS(m, d, m->opt.iterations);
|
|
break;
|
|
|
|
case mjSOL_CG: // CG
|
|
mj_solCG(m, d, m->opt.iterations);
|
|
break;
|
|
|
|
case mjSOL_NEWTON: // Newton
|
|
mj_solNewton(m, d, m->opt.iterations);
|
|
break;
|
|
|
|
default:
|
|
mjERROR("unknown solver type %d", m->opt.solver);
|
|
}
|
|
}
|
|
|
|
// run noslip solver if enabled
|
|
if (m->opt.noslip_iterations > 0) {
|
|
mj_solNoSlip(m, d, m->opt.noslip_iterations);
|
|
}
|
|
|
|
TM_END(mjTIMER_CONSTRAINT);
|
|
}
|
|
|
|
|
|
//-------------------------- state advancement and integration ------------------------------------
|
|
|
|
// advance state and time given activation derivatives, acceleration, and optional velocity
|
|
static void mj_advance(const mjModel* m, mjData* d,
|
|
const mjtNum* act_dot, const mjtNum* qacc, const mjtNum* qvel) {
|
|
int nu = m->nu, nsensor = m->nsensor;
|
|
|
|
// advance history buffers
|
|
if (m->nhistory > 0) {
|
|
// advance ctrl history buffers
|
|
for (int i = 0; i < nu; i++) {
|
|
int nsample = m->actuator_history[2*i];
|
|
if (nsample == 0) continue;
|
|
|
|
// get history buffer pointer and insert ctrl at current time
|
|
mjtNum* buf = d->history + m->actuator_historyadr[i];
|
|
*mju_historyInsert(buf, nsample, /*dim=*/1, d->time) = d->ctrl[i];
|
|
}
|
|
|
|
// advance sensor history buffers
|
|
for (int i = 0; i < nsensor; i++) {
|
|
int nsample = m->sensor_history[2*i];
|
|
if (nsample == 0) continue;
|
|
|
|
// get history buffer parameters
|
|
int dim = m->sensor_dim[i];
|
|
mjtNum* buf = d->history + m->sensor_historyadr[i];
|
|
mjtNum delay = m->sensor_delay[i];
|
|
mjtNum interval = m->sensor_interval[2*i];
|
|
|
|
if (interval > 0) {
|
|
// interval mode: if condition is satisfied, compute; otherwise copy
|
|
mjtNum time_prev = buf[0]; // first slot stores previous sensor tick
|
|
if (time_prev + interval <= d->time) {
|
|
buf[0] += interval; // advance by exact interval (continuous time)
|
|
mjtNum* slot = mju_historyInsert(buf, nsample, dim, d->time);
|
|
if (delay > 0) {
|
|
// have delay, compute sensor
|
|
mj_computeSensor(m, d, i, slot);
|
|
} else {
|
|
// no delay, copy from sensordata (already computed)
|
|
mju_copy(slot, d->sensordata + m->sensor_adr[i], dim);
|
|
}
|
|
}
|
|
} else if (delay > 0) {
|
|
// delay-only mode: always compute and insert
|
|
mjtNum* slot = mju_historyInsert(buf, nsample, dim, d->time);
|
|
mj_computeSensor(m, d, i, slot);
|
|
} else {
|
|
// history-only mode: copy from sensordata (already computed)
|
|
mjtNum* slot = mju_historyInsert(buf, nsample, dim, d->time);
|
|
mju_copy(slot, d->sensordata + m->sensor_adr[i], dim);
|
|
}
|
|
}
|
|
}
|
|
|
|
// advance activations
|
|
if (m->na && !mjDISABLED(mjDSBL_ACTUATION)) {
|
|
for (int i=0; i < nu; i++) {
|
|
int actadr = m->actuator_actadr[i];
|
|
int actadr_end = actadr + m->actuator_actnum[i];
|
|
for (int j=actadr; j < actadr_end; j++) {
|
|
// if disabled, set act_dot to 0
|
|
d->act[j] = mj_nextActivation(m, d, i, j, mj_actuatorDisabled(m, i) ? 0 : act_dot[j]);
|
|
}
|
|
}
|
|
}
|
|
|
|
// put islands to sleep according to velocity tolerance
|
|
if (mj_sleep(m, d)) {
|
|
// if any trees put to sleep (qvel set to 0), recompute all velocity-dependent quantities
|
|
mj_forwardSkip(m, d, mjSTAGE_POS, 0);
|
|
|
|
// update sleep indices
|
|
mj_updateSleep(m, d);
|
|
}
|
|
|
|
// advance velocities
|
|
int sleep_filter = mjENABLED(mjENBL_SLEEP) && d->ntree_awake < m->ntree;
|
|
if (sleep_filter) {
|
|
mju_addToSclInd(d->qvel, qacc, d->dof_awake_ind, m->opt.timestep, d->nv_awake);
|
|
} else {
|
|
mju_addToScl(d->qvel, qacc, m->opt.timestep, m->nv);
|
|
}
|
|
|
|
// advance positions with qvel if given, d->qvel otherwise (semi-implicit)
|
|
const int* index = sleep_filter ? d->body_awake_ind : NULL;
|
|
int nbody = sleep_filter ? d->nbody_awake : m->nbody;
|
|
mj_integratePosInd(m, d->qpos, qvel ? qvel : d->qvel, m->opt.timestep, index, nbody);
|
|
|
|
// advance time
|
|
d->time += m->opt.timestep;
|
|
|
|
// advance plugin states
|
|
if (m->nplugin) {
|
|
const int nslot = mjp_pluginCount();
|
|
for (int i = 0; i < m->nplugin; ++i) {
|
|
const int slot = m->plugin[i];
|
|
const mjpPlugin* plugin = mjp_getPluginAtSlotUnsafe(slot, nslot);
|
|
if (!plugin) {
|
|
mjERROR("invalid plugin slot: %d", slot);
|
|
}
|
|
if (plugin->advance) {
|
|
plugin->advance(m, d, i);
|
|
}
|
|
}
|
|
}
|
|
|
|
// save qacc for next step warmstart
|
|
mju_copy(d->qacc_warmstart, d->qacc, m->nv);
|
|
}
|
|
|
|
// Euler integrator, semi-implicit in velocity, possibly skipping factorisation
|
|
void mj_EulerSkip(const mjModel* m, mjData* d, int skipfactor) {
|
|
TM_START;
|
|
mj_markStack(d);
|
|
mjtNum* qfrc = mjSTACKALLOC(d, m->nv, mjtNum);
|
|
mjtNum* qacc = mjSTACKALLOC(d, m->nv, mjtNum);
|
|
|
|
// sleep filtering
|
|
int sleep_filter = mjENABLED(mjENBL_SLEEP) && d->nv_awake < m->nv;
|
|
int nv = sleep_filter ? d->nv_awake : m->nv;
|
|
const int* dof_awake_ind = sleep_filter ? d->dof_awake_ind : NULL;
|
|
|
|
// check for dof damping if disable flag is not set
|
|
int dof_damping = 0;
|
|
if (!mjDISABLED(mjDSBL_EULERDAMP) && !mjDISABLED(mjDSBL_DAMPER)) {
|
|
for (int v=0; v < nv; v++) {
|
|
int i = sleep_filter ? dof_awake_ind[v] : v;
|
|
if (m->dof_damping[i] > 0) {
|
|
dof_damping = 1;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// no damping or disabled: explicit velocity integration
|
|
if (!dof_damping) {
|
|
if (sleep_filter) {
|
|
mju_copyInd(qacc, d->qacc, dof_awake_ind, nv);
|
|
} else {
|
|
mju_copy(qacc, d->qacc, nv);
|
|
}
|
|
}
|
|
|
|
// damping: integrate implicitly
|
|
else {
|
|
if (!skipfactor) {
|
|
// qH = M
|
|
if (sleep_filter) {
|
|
mju_copySparse(d->qH, d->M, m->M_rownnz, m->M_rowadr, dof_awake_ind, d->nv_awake);
|
|
} else {
|
|
mju_copy(d->qH, d->M, m->nC);
|
|
}
|
|
|
|
// qH += h*diag(B)
|
|
for (int v=0; v < nv; v++) {
|
|
int i = sleep_filter ? dof_awake_ind[v] : v;
|
|
d->qH[m->M_rowadr[i] + m->M_rownnz[i] - 1] += m->opt.timestep * m->dof_damping[i];
|
|
}
|
|
|
|
// factorize in-place
|
|
mj_factorI(d->qH, d->qHDiagInv, nv, m->M_rownnz, m->M_rowadr, m->M_colind, dof_awake_ind);
|
|
}
|
|
|
|
// solve
|
|
if (sleep_filter) {
|
|
mju_addInd(qfrc, d->qfrc_smooth, d->qfrc_constraint, dof_awake_ind, nv);
|
|
mju_copyInd(qacc, qfrc, dof_awake_ind, nv);
|
|
} else {
|
|
mju_add(qfrc, d->qfrc_smooth, d->qfrc_constraint, nv);
|
|
mju_copy(qacc, qfrc, nv);
|
|
}
|
|
mj_solveLD(qacc, d->qH, d->qHDiagInv, nv, 1,
|
|
m->M_rownnz, m->M_rowadr, m->M_colind, dof_awake_ind);
|
|
}
|
|
|
|
// advance state and time
|
|
mj_advance(m, d, d->act_dot, qacc, NULL);
|
|
|
|
mj_freeStack(d);
|
|
|
|
TM_END(mjTIMER_ADVANCE);
|
|
}
|
|
|
|
|
|
// Euler integrator, semi-implicit in velocity
|
|
void mj_Euler(const mjModel* m, mjData* d) {
|
|
mj_EulerSkip(m, d, 0);
|
|
}
|
|
|
|
|
|
// RK4 tableau
|
|
const mjtNum RK4_A[9] = {
|
|
0.5, 0, 0,
|
|
0, 0.5, 0,
|
|
0, 0, 1
|
|
};
|
|
|
|
const mjtNum RK4_B[4] = {
|
|
1.0/6.0, 1.0/3.0, 1.0/3.0, 1.0/6.0
|
|
};
|
|
|
|
|
|
// Runge Kutta explicit order-N integrator
|
|
// (A,B) is the tableau, C is set to row_sum(A)
|
|
void mj_RungeKutta(const mjModel* m, mjData* d, int N) {
|
|
int nv = m->nv, nq = m->nq, na = m->na;
|
|
mjtNum h = m->opt.timestep, time = d->time;
|
|
mjtNum C[9], T[9], *X[10], *F[10], *dX;
|
|
const mjtNum* A = (N == 4 ? RK4_A : 0);
|
|
const mjtNum* B = (N == 4 ? RK4_B : 0);
|
|
|
|
// check order
|
|
if (!A) {
|
|
mjERROR("supported RK orders: N=4");
|
|
}
|
|
|
|
// allocate space for intermediate solutions
|
|
mj_markStack(d);
|
|
dX = mjSTACKALLOC(d, 2*nv+na, mjtNum);
|
|
for (int i=0; i < N; i++) {
|
|
X[i] = mjSTACKALLOC(d, nq+nv+na, mjtNum);
|
|
F[i] = mjSTACKALLOC(d, nv+na, mjtNum);
|
|
}
|
|
|
|
// precompute C and T; C,T,A have size (N-1)
|
|
for (int i=1; i < N; i++) {
|
|
// C(i) = sum_j A(i,j)
|
|
C[i-1] = 0;
|
|
for (int j=0; j < i; j++) {
|
|
C[i-1] += A[(i-1)*(N-1)+j];
|
|
}
|
|
|
|
// compute T
|
|
T[i-1] = d->time + C[i-1]*h;
|
|
}
|
|
|
|
// init X[0], F[0]; mj_forward() was already called
|
|
mju_copy(X[0], d->qpos, nq);
|
|
mju_copy(X[0]+nq, d->qvel, nv);
|
|
mju_copy(F[0], d->qacc, nv);
|
|
if (na) {
|
|
mju_copy(X[0]+nq+nv, d->act, na);
|
|
mju_copy(F[0]+nv, d->act_dot, na);
|
|
}
|
|
|
|
// compute the remaining X[i], F[i]
|
|
for (int i=1; i < N; i++) {
|
|
// compute dX
|
|
mju_zero(dX, 2*nv+na);
|
|
for (int j=0; j < i; j++) {
|
|
mju_addToScl(dX, X[j]+nq, A[(i-1)*(N-1)+j], nv);
|
|
mju_addToScl(dX+nv, F[j], A[(i-1)*(N-1)+j], nv+na);
|
|
}
|
|
|
|
// compute X[i] = X[0] '+' dX
|
|
mju_copy(X[i], X[0], nq+nv+na);
|
|
mj_integratePos(m, X[i], dX, h);
|
|
mju_addToScl(X[i]+nq, dX+nv, h, nv+na);
|
|
|
|
// set X[i], T[i-1] in mjData
|
|
mju_copy(d->qpos, X[i], nq);
|
|
mju_copy(d->qvel, X[i]+nq, nv);
|
|
if (na) {
|
|
mju_copy(d->act, X[i]+nq+nv, na);
|
|
}
|
|
d->time = T[i-1];
|
|
|
|
// evaluate F[i]
|
|
mj_forwardSkip(m, d, mjSTAGE_NONE, 1); // 1: do not recompute sensors and energy
|
|
mju_copy(F[i], d->qacc, nv);
|
|
if (na) {
|
|
mju_copy(F[i]+nv, d->act_dot, na);
|
|
}
|
|
}
|
|
|
|
// compute dX for final update (using B instead of A)
|
|
mju_zero(dX, 2*nv+na);
|
|
for (int j=0; j < N; j++) {
|
|
mju_addToScl(dX, X[j]+nq, B[j], nv);
|
|
mju_addToScl(dX+nv, F[j], B[j], nv+na);
|
|
}
|
|
|
|
// reset state and time
|
|
d->time = time;
|
|
mju_copy(d->qpos, X[0], nq);
|
|
mju_copy(d->qvel, X[0]+nq, nv);
|
|
mju_copy(d->act, X[0]+nq+nv, na);
|
|
|
|
// advance state and time
|
|
mj_advance(m, d, dX+2*nv, dX+nv, dX);
|
|
|
|
mj_freeStack(d);
|
|
}
|
|
|
|
|
|
// fully implicit in velocity, possibly skipping factorization
|
|
void mj_implicitSkip(const mjModel* m, mjData* d, int skipfactor) {
|
|
TM_START;
|
|
int nD = m->nD, nC = m->nC;
|
|
|
|
mj_markStack(d);
|
|
mjtNum* qfrc = mjSTACKALLOC(d, m->nv, mjtNum);
|
|
mjtNum* qacc = mjSTACKALLOC(d, m->nv, mjtNum);
|
|
|
|
// sleep filtering
|
|
int sleep_filter = mjENABLED(mjENBL_SLEEP) && d->nv_awake < m->nv;
|
|
int nv = sleep_filter ? d->nv_awake : m->nv;
|
|
const int* dof_awake_ind = sleep_filter ? d->dof_awake_ind : NULL;
|
|
|
|
// set qfrc = qfrc_smooth + qfrc_constraint
|
|
if (sleep_filter) {
|
|
mju_addInd(qfrc, d->qfrc_smooth, d->qfrc_constraint, dof_awake_ind, nv);
|
|
} else {
|
|
mju_add(qfrc, d->qfrc_smooth, d->qfrc_constraint, nv);
|
|
}
|
|
|
|
// check for flex_interp
|
|
int has_flex_interp = 0;
|
|
for (int f = 0; f < m->nflex; f++) {
|
|
if (m->flex_interp[f]) {
|
|
has_flex_interp = 1;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// flex: data structures for reduced dense factorization
|
|
mjtNum* H_flex = NULL;
|
|
int* flex_dof_indices = NULL;
|
|
int nflexdofs = 0;
|
|
int ncoupling = 0;
|
|
mjtNum* coupling_val = NULL;
|
|
int* coupling_row = NULL;
|
|
int* coupling_col = NULL;
|
|
|
|
// factorization
|
|
if (!skipfactor) {
|
|
// implicit
|
|
if (m->opt.integrator == mjINT_IMPLICIT) {
|
|
// compute analytical derivative qDeriv
|
|
mjd_smooth_vel(m, d, /* flg_bias = */ 1);
|
|
|
|
// gather qLU <- M (lower to full)
|
|
mju_gatherMasked(d->qLU, d->M, m->mapM2D, nD);
|
|
|
|
// set qLU = M - dt*qDeriv
|
|
mju_addToScl(d->qLU, d->qDeriv, -m->opt.timestep, nD);
|
|
}
|
|
|
|
// implicitfast
|
|
else if (m->opt.integrator == mjINT_IMPLICITFAST) {
|
|
// compute analytical derivative qDeriv; skip rne derivative
|
|
mjd_smooth_vel(m, d, /* flg_bias = */ 0);
|
|
|
|
// modified mass matrix: gather qH <- qDeriv (full to lower)
|
|
mju_gather(d->qH, d->qDeriv, m->mapD2M, nC);
|
|
|
|
// set qH = M - dt*qDeriv
|
|
mju_addScl(d->qH, d->M, d->qH, -m->opt.timestep, nC);
|
|
} else {
|
|
mjERROR("integrator must be implicit or implicitfast");
|
|
}
|
|
|
|
// flex: reduced dense factorization
|
|
if (has_flex_interp && !sleep_filter) {
|
|
// temporary allocations for body chain
|
|
int* chain_dofs = mjSTACKALLOC(d, nv, int);
|
|
int* seen_dof = mjSTACKALLOC(d, nv, int);
|
|
mju_fillInt(seen_dof, 0, nv);
|
|
|
|
// identify flex DOFs
|
|
// For pinned nodes (body_dofnum==0): use bodyChain to include parent DOFs
|
|
// For regular flex nodes: use body_dofadr for one-way coupling
|
|
for (int f=0; f < m->nflex; f++) {
|
|
if (m->flex_interp[f]) {
|
|
int nodenum = m->flex_nodenum[f];
|
|
int nodeadr = m->flex_nodeadr[f];
|
|
for (int n=0; n < nodenum; n++) {
|
|
int b = m->flex_nodebodyid[nodeadr + n];
|
|
int chain_nnz;
|
|
if (m->body_dofnum[b] == 0) {
|
|
// Pinned node: use bodyChain to get parent DOFs
|
|
chain_nnz = mj_bodyChain(m, b, chain_dofs);
|
|
} else {
|
|
// Regular flex node: use body's own DOFs only
|
|
chain_nnz = m->body_dofnum[b];
|
|
for (int j = 0; j < chain_nnz; j++) {
|
|
chain_dofs[j] = m->body_dofadr[b] + j;
|
|
}
|
|
}
|
|
for (int i=0; i < chain_nnz; i++) {
|
|
int dof = chain_dofs[i];
|
|
if (!seen_dof[dof]) {
|
|
seen_dof[dof] = 1;
|
|
nflexdofs++;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// allocations
|
|
if (nflexdofs > 0) {
|
|
flex_dof_indices = mjSTACKALLOC(d, nflexdofs, int);
|
|
int* global2local = mjSTACKALLOC(d, nv, int);
|
|
mju_fillInt(global2local, -1, nv);
|
|
|
|
// collect unique DOFs in order
|
|
int cnt = 0;
|
|
mju_fillInt(seen_dof, 0, nv);
|
|
for (int f=0; f < m->nflex; f++) {
|
|
if (m->flex_interp[f]) {
|
|
int nodenum = m->flex_nodenum[f];
|
|
int nodeadr = m->flex_nodeadr[f];
|
|
for (int n=0; n < nodenum; n++) {
|
|
int b = m->flex_nodebodyid[nodeadr + n];
|
|
int chain_nnz;
|
|
if (m->body_dofnum[b] == 0) {
|
|
// Pinned node: use bodyChain to get parent DOFs
|
|
chain_nnz = mj_bodyChain(m, b, chain_dofs);
|
|
} else {
|
|
// Regular flex node: use body's own DOFs only
|
|
chain_nnz = m->body_dofnum[b];
|
|
for (int j = 0; j < chain_nnz; j++) {
|
|
chain_dofs[j] = m->body_dofadr[b] + j;
|
|
}
|
|
}
|
|
for (int i=0; i < chain_nnz; i++) {
|
|
int dof = chain_dofs[i];
|
|
if (!seen_dof[dof]) {
|
|
seen_dof[dof] = 1;
|
|
flex_dof_indices[cnt] = dof;
|
|
global2local[dof] = cnt;
|
|
cnt++;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
const int* rownnz = (m->opt.integrator == mjINT_IMPLICIT) ? m->D_rownnz : m->M_rownnz;
|
|
const int* rowadr = (m->opt.integrator == mjINT_IMPLICIT) ? m->D_rowadr : m->M_rowadr;
|
|
const int* colind = (m->opt.integrator == mjINT_IMPLICIT) ? m->D_colind : m->M_colind;
|
|
const mjtNum* source = (m->opt.integrator == mjINT_IMPLICIT) ? d->qLU : d->qH;
|
|
|
|
// count coupling terms (off-diagonal: flex row, non-flex col)
|
|
for (int i=0; i < nflexdofs; i++) {
|
|
int row = flex_dof_indices[i];
|
|
int start = rowadr[row];
|
|
int end = start + rownnz[row];
|
|
for (int k=start; k < end; k++) {
|
|
if (global2local[colind[k]] < 0) {
|
|
ncoupling++;
|
|
}
|
|
}
|
|
}
|
|
|
|
// allocate coupling storage
|
|
if (ncoupling > 0) {
|
|
coupling_val = mjSTACKALLOC(d, ncoupling, mjtNum);
|
|
coupling_row = mjSTACKALLOC(d, ncoupling, int);
|
|
coupling_col = mjSTACKALLOC(d, ncoupling, int);
|
|
}
|
|
|
|
// build H_flex (dense) from qLU (implicit) or qH (implicitfast)
|
|
H_flex = mjSTACKALLOC(d, nflexdofs*nflexdofs, mjtNum);
|
|
mju_zero(H_flex, nflexdofs*nflexdofs);
|
|
|
|
int coup_cnt = 0;
|
|
for (int i=0; i < nflexdofs; i++) {
|
|
int row = flex_dof_indices[i];
|
|
int start = rowadr[row];
|
|
int end = start + rownnz[row];
|
|
for (int k=start; k < end; k++) {
|
|
int col = colind[k];
|
|
int local_j = global2local[col];
|
|
if (local_j >= 0) {
|
|
H_flex[i*nflexdofs + local_j] = source[k];
|
|
} else if (coup_cnt < ncoupling) {
|
|
coupling_val[coup_cnt] = source[k];
|
|
coupling_row[coup_cnt] = i; // local flex index
|
|
coupling_col[coup_cnt] = col; // global parent index
|
|
coup_cnt++;
|
|
}
|
|
}
|
|
}
|
|
|
|
// add stiffness to H_flex
|
|
mjtNum h = m->opt.timestep;
|
|
mjd_flexInterp_addH(m, d, H_flex, flex_dof_indices, nflexdofs, h);
|
|
|
|
// factor H_flex
|
|
mju_cholFactor(H_flex, nflexdofs, mjMINVAL);
|
|
}
|
|
}
|
|
|
|
// standard factorization (implicit / implicitfast)
|
|
if (m->opt.integrator == mjINT_IMPLICIT) {
|
|
int* scratch = mjSTACKALLOC(d, nv, int);
|
|
mju_factorLUSparse(d->qLU, nv, scratch, m->D_rownnz, m->D_rowadr, m->D_colind, dof_awake_ind);
|
|
} else {
|
|
mj_factorI(d->qH, d->qHDiagInv, nv, m->M_rownnz, m->M_rowadr, m->M_colind, dof_awake_ind);
|
|
}
|
|
}
|
|
|
|
// solve
|
|
// standard sparse solve
|
|
if (m->opt.integrator == mjINT_IMPLICIT) {
|
|
mju_solveLUSparse(qacc, d->qLU, qfrc, nv, m->D_rownnz, m->D_rowadr, m->D_diag, m->D_colind,
|
|
dof_awake_ind);
|
|
} else {
|
|
// implicitfast
|
|
if (sleep_filter) {
|
|
mju_copyInd(qacc, qfrc, dof_awake_ind, nv);
|
|
} else {
|
|
mju_copy(qacc, qfrc, nv);
|
|
}
|
|
mj_solveLD(qacc, d->qH, d->qHDiagInv, nv, 1, m->M_rownnz, m->M_rowadr, m->M_colind, dof_awake_ind);
|
|
}
|
|
|
|
// flex: reduced dense solve
|
|
if (H_flex) {
|
|
// compute qfrc_flex
|
|
mjtNum* qfrc_flex = mjSTACKALLOC(d, nflexdofs, mjtNum);
|
|
mjtNum* res = mjSTACKALLOC(d, nv, mjtNum);
|
|
|
|
mjtNum h = m->opt.timestep;
|
|
mjtNum damp = (m->nflex > 0 && m->flex_damping) ? m->flex_damping[0] : 0;
|
|
mjtNum scl = h * h + h * damp;
|
|
mjtNum factor = (scl > mjMINVAL) ? (h/scl) : 0;
|
|
|
|
// velocity correction: -h * K * v
|
|
mju_zero(res, nv);
|
|
mjd_flexInterp_mulKD(m, d, res, d->qvel, h); // returns -scl * K * v
|
|
|
|
for (int i=0; i < nflexdofs; i++) {
|
|
int global_dof = flex_dof_indices[i];
|
|
qfrc_flex[i] = qfrc[global_dof] + res[global_dof] * factor;
|
|
}
|
|
|
|
// apply coupling correction: qfrc_flex -= H_coupling * qacc_parent
|
|
if (ncoupling > 0) {
|
|
for (int k=0; k < ncoupling; k++) {
|
|
qfrc_flex[coupling_row[k]] -= coupling_val[k] * qacc[coupling_col[k]];
|
|
}
|
|
}
|
|
|
|
// solve H_flex * qacc_flex = qfrc_flex
|
|
// reuse qfrc_flex as result buffer (qacc_flex)
|
|
mju_cholSolve(qfrc_flex, H_flex, qfrc_flex, nflexdofs);
|
|
|
|
// overwrite flex DOFs with reduced dense solution
|
|
mju_scatter(qacc, qfrc_flex, flex_dof_indices, nflexdofs);
|
|
}
|
|
|
|
// advance state and time
|
|
mj_advance(m, d, d->act_dot, qacc, NULL);
|
|
|
|
mj_freeStack(d);
|
|
|
|
TM_END(mjTIMER_ADVANCE);
|
|
}
|
|
|
|
|
|
// fully implicit in velocity
|
|
void mj_implicit(const mjModel* m, mjData* d) {
|
|
mj_implicitSkip(m, d, 0);
|
|
}
|
|
|
|
|
|
//-------------------------- top-level API ---------------------------------------------------------
|
|
|
|
// forward dynamics with skip; skipstage is mjtStage
|
|
void mj_forwardSkip(const mjModel* m, mjData* d, int skipstage, int skipsensor) {
|
|
TM_START;
|
|
|
|
// position-dependent
|
|
if (skipstage < mjSTAGE_POS) {
|
|
mj_fwdPosition(m, d);
|
|
|
|
if (!skipsensor) {
|
|
mj_sensorPos(m, d);
|
|
}
|
|
|
|
if (!d->flg_energypos) {
|
|
if (mjENABLED(mjENBL_ENERGY)) {
|
|
mj_energyPos(m, d);
|
|
} else {
|
|
d->energy[0] = d->energy[1] = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
// velocity-dependent
|
|
if (skipstage < mjSTAGE_VEL) {
|
|
mj_fwdVelocity(m, d);
|
|
|
|
if (!skipsensor) {
|
|
mj_sensorVel(m, d);
|
|
}
|
|
|
|
if (mjENABLED(mjENBL_ENERGY) && !d->flg_energyvel) {
|
|
mj_energyVel(m, d);
|
|
}
|
|
}
|
|
|
|
// acceleration-dependent
|
|
if (mjcb_control && !mjDISABLED(mjDSBL_ACTUATION)) {
|
|
mjcb_control(m, d);
|
|
}
|
|
|
|
mj_fwdActuation(m, d);
|
|
mj_fwdAcceleration(m, d);
|
|
mj_fwdConstraint(m, d);
|
|
if (!skipsensor) {
|
|
d->flg_rnepost = 0; // clear flag for lazy evaluation
|
|
mj_sensorAcc(m, d);
|
|
}
|
|
|
|
TM_END(mjTIMER_FORWARD);
|
|
}
|
|
|
|
|
|
// forward dynamics
|
|
void mj_forward(const mjModel* m, mjData* d) {
|
|
mj_forwardSkip(m, d, mjSTAGE_NONE, 0);
|
|
}
|
|
|
|
|
|
// advance simulation using control callback
|
|
void mj_step(const mjModel* m, mjData* d) {
|
|
TM_START;
|
|
|
|
// common to all integrators
|
|
mj_checkPos(m, d);
|
|
mj_checkVel(m, d);
|
|
mj_forward(m, d);
|
|
mj_checkAcc(m, d);
|
|
|
|
// compare forward and inverse solutions if enabled
|
|
if (mjENABLED(mjENBL_FWDINV)) {
|
|
mj_compareFwdInv(m, d);
|
|
}
|
|
|
|
// use selected integrator
|
|
switch ((mjtIntegrator) m->opt.integrator) {
|
|
case mjINT_EULER:
|
|
mj_Euler(m, d);
|
|
break;
|
|
|
|
case mjINT_RK4:
|
|
mj_RungeKutta(m, d, 4);
|
|
break;
|
|
|
|
case mjINT_IMPLICIT:
|
|
case mjINT_IMPLICITFAST:
|
|
mj_implicit(m, d);
|
|
break;
|
|
|
|
default:
|
|
mjERROR("invalid integrator");
|
|
}
|
|
|
|
TM_END(mjTIMER_STEP);
|
|
}
|
|
|
|
|
|
// advance simulation in two phases: before input is set by user
|
|
void mj_step1(const mjModel* m, mjData* d) {
|
|
TM_START;
|
|
mj_checkPos(m, d);
|
|
mj_checkVel(m, d);
|
|
mj_fwdPosition(m, d);
|
|
mj_sensorPos(m, d);
|
|
|
|
if (!d->flg_energypos) {
|
|
if (mjENABLED(mjENBL_ENERGY)) {
|
|
mj_energyPos(m, d);
|
|
} else {
|
|
d->energy[0] = d->energy[1] = 0;
|
|
}
|
|
}
|
|
|
|
mj_fwdVelocity(m, d);
|
|
mj_sensorVel(m, d);
|
|
if (mjENABLED(mjENBL_ENERGY) && !d->flg_energyvel) {
|
|
mj_energyVel(m, d);
|
|
}
|
|
|
|
if (mjcb_control) {
|
|
mjcb_control(m, d);
|
|
}
|
|
TM_END(mjTIMER_STEP);
|
|
}
|
|
|
|
|
|
// >>>> user can modify ctrl and q/xfrc_applied between step1 and step2 <<<<
|
|
|
|
|
|
// advance simulation in two phases: after input is set by user
|
|
void mj_step2(const mjModel* m, mjData* d) {
|
|
TM_START;
|
|
mj_fwdActuation(m, d);
|
|
mj_fwdAcceleration(m, d);
|
|
mj_fwdConstraint(m, d);
|
|
mj_sensorAcc(m, d);
|
|
mj_checkAcc(m, d);
|
|
|
|
// compare forward and inverse solutions if enabled
|
|
if (mjENABLED(mjENBL_FWDINV)) {
|
|
mj_compareFwdInv(m, d);
|
|
}
|
|
|
|
// integrate with Euler or implicit; RK4 defaults to Euler
|
|
if (m->opt.integrator == mjINT_IMPLICIT || m->opt.integrator == mjINT_IMPLICITFAST) {
|
|
mj_implicit(m, d);
|
|
} else {
|
|
mj_Euler(m, d);
|
|
}
|
|
|
|
d->timer[mjTIMER_STEP].number--;
|
|
TM_END(mjTIMER_STEP);
|
|
}
|