Add options for controlling early termination criteria of CG/Newton linesearch.

Useful for performance tuning models.

PiperOrigin-RevId: 563175078
Change-Id: Id64a510d6080038ea8d5876dabbf0b2b311435bb

src/engine/engine_io.c

@@ -113,6 +113,9 @@ void mj_defaultSolRefImp(mjtNum* solref, mjtNum* solimp) {
 
 // set model options to default values
 void mj_defaultOption(mjOption* opt) {
+  // fill opt with zeros in case struct is padded
+  memset(opt, 0, sizeof(mjOption));
+
   // timing parameters
   opt->timestep           = 0.002;
   opt->apirate            = 100;
@@ -120,6 +123,7 @@ void mj_defaultOption(mjOption* opt) {
   // solver parameters
   opt->impratio           = 1;
   opt->tolerance          = 1e-8;
+  opt->ls_tolerance       = 0.01;
   opt->noslip_tolerance   = 1e-6;
   opt->mpr_tolerance      = 1e-6;
 
@@ -147,6 +151,7 @@ void mj_defaultOption(mjOption* opt) {
   opt->jacobian           = mjJAC_AUTO;
   opt->solver             = mjSOL_NEWTON;
   opt->iterations         = 100;
+  opt->ls_iterations      = 50;
   opt->noslip_iterations  = 0;
   opt->mpr_iterations     = 50;
   opt->disableflags       = 0;

src/engine/engine_solver.c

@@ -1093,9 +1093,6 @@ static int updateBracket(const mjModel* m, mjData* d, mjCGContext* ctx,
 static mjtNum CGsearch(const mjModel* m, mjData* d, mjCGContext* ctx) {
   mjCGPnt p0, p1, p2, pmid, p1next, p2next;
 
-  const int LSmaxiter = 50;
-  const mjtNum LStolscl = 0.01;
-
   // clear results
   ctx->LSiter = 0;
   ctx->LSresult = 0;
@@ -1109,7 +1106,7 @@ static mjtNum CGsearch(const mjModel* m, mjData* d, mjCGContext* ctx) {
   }
 
   // compute scaled gradtol and slope scaling
-  mjtNum gtol = m->opt.tolerance * LStolscl * snorm * m->stat.meaninertia * mjMAX(1, m->nv);
+  mjtNum gtol = m->opt.tolerance * m->opt.ls_tolerance * snorm * m->stat.meaninertia * mjMAX(1, m->nv);
   mjtNum slopescl = 1 / (snorm * m->stat.meaninertia * mjMAX(1, m->nv));
 
   // compute Mv, Jv
@@ -1180,7 +1177,7 @@ static mjtNum CGsearch(const mjModel* m, mjData* d, mjCGContext* ctx) {
 
   // one-sided search
   int p2update = 0;
-  while (p1.deriv[0]*dir <= -gtol && ctx->LSiter < LSmaxiter) {
+  while (p1.deriv[0]*dir <= -gtol && ctx->LSiter < m->opt.ls_iterations) {
     // save current
     p2 = p1;
     p2update = 1;
@@ -1197,7 +1194,7 @@ static mjtNum CGsearch(const mjModel* m, mjData* d, mjCGContext* ctx) {
   }
 
   // check for failure to bracket
-  if (ctx->LSiter >= LSmaxiter) {
+  if (ctx->LSiter >= m->opt.ls_iterations) {
     ctx->LSresult = 3;                          // could not bracket
     ctx->LSslope = mju_abs(p1.deriv[0])*slopescl;
     return p1.alpha;
@@ -1216,7 +1213,7 @@ static mjtNum CGsearch(const mjModel* m, mjData* d, mjCGContext* ctx) {
   CGeval(m, d, ctx, &p1next);
 
   // bracketed search
-  while (ctx->LSiter < LSmaxiter) {
+  while (ctx->LSiter < m->opt.ls_iterations) {
     // evaluate at midpoint
     pmid.alpha = 0.5*(p1.alpha + p2.alpha);
     CGeval(m, d, ctx, &pmid);

src/xml/xml_native_reader.cc

@@ -95,12 +95,12 @@ static const char* MJCF[nMJCF][mjXATTRNUM] = {
             "inttotal", "interval", "tolrange"},
     {">"},
 
-    {"option", "*", "24",
-        "timestep", "apirate", "impratio", "tolerance", "noslip_tolerance", "mpr_tolerance",
-        "gravity", "wind", "magnetic", "density", "viscosity",
+    {"option", "*", "26",
+        "timestep", "apirate", "impratio", "tolerance", "ls_tolerance", "noslip_tolerance",
+        "mpr_tolerance", "gravity", "wind", "magnetic", "density", "viscosity",
         "o_margin", "o_solref", "o_solimp",
         "integrator", "collision", "cone", "jacobian",
-        "solver", "iterations", "noslip_iterations", "mpr_iterations",
+        "solver", "iterations", "ls_iterations", "noslip_iterations", "mpr_iterations",
         "sdf_iterations", "sdf_initpoints"},
     {"<"},
         {"flag", "?", "22", "constraint", "equality", "frictionloss", "limit", "contact",
@@ -958,6 +958,7 @@ void mjXReader::Option(XMLElement* section, mjOption* opt) {
   ReadAttr(section, "apirate", 1, &opt->apirate, text);
   ReadAttr(section, "impratio", 1, &opt->impratio, text);
   ReadAttr(section, "tolerance", 1, &opt->tolerance, text);
+  ReadAttr(section, "ls_tolerance", 1, &opt->ls_tolerance, text);
   ReadAttr(section, "noslip_tolerance", 1, &opt->noslip_tolerance, text);
   ReadAttr(section, "mpr_tolerance", 1, &opt->mpr_tolerance, text);
   ReadAttr(section, "gravity", 3, opt->gravity, text);
@@ -976,6 +977,7 @@ void mjXReader::Option(XMLElement* section, mjOption* opt) {
   MapValue(section, "jacobian", &opt->jacobian, jac_map, jac_sz);
   MapValue(section, "solver", &opt->solver, solver_map, solver_sz);
   ReadAttrInt(section, "iterations", &opt->iterations);
+  ReadAttrInt(section, "ls_iterations", &opt->ls_iterations);
   ReadAttrInt(section, "noslip_iterations", &opt->noslip_iterations);
   ReadAttrInt(section, "mpr_iterations", &opt->mpr_iterations);
   ReadAttrInt(section, "sdf_iterations", &opt->sdf_iterations);

src/xml/xml_native_writer.cc

@@ -793,6 +793,7 @@ void mjXWriter::Option(XMLElement* root) {
   WriteAttr(section, "apirate", 1, &model->option.apirate, &opt.apirate);
   WriteAttr(section, "impratio", 1, &model->option.impratio, &opt.impratio);
   WriteAttr(section, "tolerance", 1, &model->option.tolerance, &opt.tolerance);
+  WriteAttr(section, "ls_tolerance", 1, &model->option.ls_tolerance, &opt.ls_tolerance);
   WriteAttr(section, "noslip_tolerance", 1, &model->option.noslip_tolerance, &opt.noslip_tolerance);
   WriteAttr(section, "mpr_tolerance", 1, &model->option.mpr_tolerance, &opt.mpr_tolerance);
   WriteAttr(section, "gravity", 3, model->option.gravity, opt.gravity);
@@ -816,6 +817,7 @@ void mjXWriter::Option(XMLElement* root) {
   WriteAttrKey(section, "solver", solver_map, solver_sz,
                model->option.solver, opt.solver);
   WriteAttrInt(section, "iterations", model->option.iterations, opt.iterations);
+  WriteAttrInt(section, "ls_iterations", model->option.ls_iterations, opt.ls_iterations);
   WriteAttrInt(section, "noslip_iterations", model->option.noslip_iterations, opt.noslip_iterations);
   WriteAttrInt(section, "mpr_iterations", model->option.mpr_iterations, opt.mpr_iterations);
   WriteAttrInt(section, "sdf_iterations", model->option.sdf_iterations, opt.sdf_iterations);