Remove "global" option from [compiler/coordinate](https://mujoco.readthedocs.io/en/latest/XMLreference.html#compiler-coordinate) attribute.

Keeping this rarely-used setting complicates the compiler logic and is blocking future improvements. In order to convert older models which used this option, load and save them in MuJoCo 2.3.3 or older.

PiperOrigin-RevId: 521739137
Change-Id: If0cb40d5db4879a4db9318cc2be258a7923e6e85

src/user/user_composite.cc

@@ -213,11 +213,6 @@ void mjCComposite::SetDefault(void) {
 
 // make composite object
 bool mjCComposite::Make(mjCModel* model, mjCBody* body, char* error, int error_sz) {
-  // require local coordinates
-  if (model->global) {
-    return comperr(error, "Composite requires local coordinates", error_sz);
-  }
-
   // check geom type
   if ((def[0].geom.type!=mjGEOM_SPHERE &&
        def[0].geom.type!=mjGEOM_CAPSULE &&

src/user/user_model.cc

@@ -89,7 +89,6 @@ mjCModel::mjCModel() {
   balanceinertia = false;
   strippath = false;
   fitaabb = false;
-  global = false;
   degree = true;
   euler[0] = 'x';
   euler[1] = 'y';

src/user/user_model.h

@@ -123,7 +123,6 @@ class mjCModel {
   bool balanceinertia;            // automatically impose A + B >= C rule
   bool strippath;                 // automatically strip paths from mesh files
   bool fitaabb;                   // meshfit to aabb instead of inertia box
-  bool global;                    // local or global coordinates
   bool degree;                    // angles in radians or degrees
   char euler[3];                  // sequence for euler rotations
   std::string meshdir;            // mesh and hfield directory

src/user/user_objects.cc

@@ -649,17 +649,8 @@ void mjCBody::GeomFrame(void) {
 // setup child local frame: pos
 void mjCBody::MakeLocal(double* _locpos, double* _locquat,
                         const double* _pos, const double* _quat) {
-  // global: transform to local
-  if (model->global) {
-    mjuu_localpos(_locpos, _pos, pos, quat);
-    mjuu_localquat(_locquat, _quat, quat);
-  }
-
-  // local: copy
-  else {
-    mjuu_copyvec(_locpos, _pos, 3);
-    mjuu_copyvec(_locquat, _quat, 4);
-  }
+  mjuu_copyvec(_locpos, _pos, 3);
+  mjuu_copyvec(_locquat, _quat, 4);
 }
 
 // set explicitinertial to true
@@ -825,9 +816,9 @@ void mjCBody::Compile(void) {
   }
   userdata.resize(model->nuser_body);
 
-  // pos defaults to (0,0,0) in local coordinates
-  if (!mjuu_defined(pos[0]) && !model->global) {
-    mjuu_setvec(pos, 0, 0, 0);
+  // pos defaults to (0,0,0)
+  if (!mjuu_defined(pos[0])) {
+     mjuu_setvec(pos, 0, 0, 0);
   }
 
   // normalize user-defined quaternions
@@ -1112,12 +1103,8 @@ int mjCJoint::Compile(void) {
     mjuu_zerovec(locpos, 3);
   }
 
-  // compute local axis relative to specified body
-  if (model->global) {
-    mjuu_localaxis(locaxis, axis, body->quat);
-  } else {
-    mjuu_copyvec(locaxis, axis, 3);
-  }
+  // copy axis to local
+  mjuu_copyvec(locaxis, axis, 3);
 
   // convert reference angles to radians for hinge joints
   if (type==mjJNT_HINGE && model->degree) {
@@ -1930,14 +1917,8 @@ void mjCLight::Compile(void) {
   // ask parent body to compute our local pos and quat relative to itself
   body->MakeLocal(locpos, locquat, pos, quat);
 
-  // copy/convert dir to local frame
-  if (model->global) {
-    double mat[9], q[4] = {locquat[0], -locquat[1], -locquat[2], -locquat[3]};
-    mjuu_quat2mat(mat, q);
-    mjuu_mulvecmat(locdir, dir, mat);
-  } else {
-    mjuu_copyvec(locdir, dir, 3);
-  }
+  // copy dir to local frame
+  mjuu_copyvec(locdir, dir, 3);
 
   // get targetbodyid
   if (!targetbody.empty()) {

src/xml/xml_native_reader.cc

@@ -863,7 +863,10 @@ void mjXReader::Compiler(XMLElement* section, mjCModel* mod) {
     mod->fitaabb = (n==1);
   }
   if (MapValue(section, "coordinate", &n, coordinate_map, 2)) {
-    mod->global = (n==1);
+    if (n==1) {
+      throw mjXError(section, "global coordinates no longer supported. To convert existing models, "
+                              "load and save them in MuJoCo 2.3.3 or older");
+    }
   }
   if (MapValue(section, "angle", &n, angle_map, 2)) {
     mod->degree = (n==1);

src/xml/xml_urdf.cc

@@ -99,7 +99,6 @@ void mjXURDF::Parse(XMLElement* root) {
   }
 
   // enforce required compiler defaults for URDF
-  model->global = false;
   model->degree = false;
 
   // get model name