Add mjs_makeMesh to create a builtin mesh.

PiperOrigin-RevId: 788538127
Change-Id: I999733399a1a0da07b0f915f34d31364ab8b3b52

python/mujoco/introspect/enums.py

@@ -791,6 +791,21 @@ ENUMS: Mapping[str, EnumDecl] = dict([
              ('mjMESH_INERTIA_SHELL', 3),
          ]),
      )),
+    ('mjtMeshBuiltin',
+     EnumDecl(
+         name='mjtMeshBuiltin',
+         declname='enum mjtMeshBuiltin_',
+         values=dict([
+             ('mjMESH_BUILTIN_NONE', 0),
+             ('mjMESH_BUILTIN_SPHERE', 1),
+             ('mjMESH_BUILTIN_HEMISPHERE', 2),
+             ('mjMESH_BUILTIN_PRISM', 3),
+             ('mjMESH_BUILTIN_CONE', 4),
+             ('mjMESH_BUILTIN_TORUS', 5),
+             ('mjMESH_BUILTIN_WEDGE', 6),
+             ('mjMESH_BUILTIN_PLATE', 7),
+         ]),
+     )),
     ('mjtBuiltin',
      EnumDecl(
          name='mjtBuiltin',

python/mujoco/introspect/functions.py

@@ -9869,6 +9869,34 @@ FUNCTIONS: Mapping[str, FunctionDecl] = dict([
          ),
          doc='Add material.',
      )),
+    ('mjs_makeMesh',
+     FunctionDecl(
+         name='mjs_makeMesh',
+         return_type=ValueType(name='int'),
+         parameters=(
+             FunctionParameterDecl(
+                 name='mesh',
+                 type=PointerType(
+                     inner_type=ValueType(name='mjsMesh'),
+                 ),
+             ),
+             FunctionParameterDecl(
+                 name='builtin',
+                 type=ValueType(name='mjtMeshBuiltin'),
+             ),
+             FunctionParameterDecl(
+                 name='params',
+                 type=PointerType(
+                     inner_type=ValueType(name='double'),
+                 ),
+             ),
+             FunctionParameterDecl(
+                 name='nparams',
+                 type=ValueType(name='int'),
+             ),
+         ),
+         doc='Sets the vertices and normals of a mesh.',
+     )),
     ('mjs_getSpec',
      FunctionDecl(
          name='mjs_getSpec',

python/mujoco/specs.cc

@@ -1001,6 +1001,38 @@ PYBIND11_MODULE(_specs, m) {
         mjs_setDefault(self.element, &default_);
       },
       py::return_value_policy::reference_internal);
+  mjsMesh.def(
+      "make_wedge",
+      [](raw::MjsMesh* self, std::array<int, 2>& resolution, double radius,
+         std::array<double, 2>& fov, double gamma) {
+        double params[5] = {static_cast<double>(resolution[0]),
+                            static_cast<double>(resolution[1]), fov[0], fov[1],
+                            gamma};
+        if (mjs_makeMesh(self, mjMESH_BUILTIN_WEDGE, params, 5)) {
+          throw pybind11::value_error(mjs_getError(mjs_getSpec(self->element)));
+        }
+      },
+      py::arg("resolution") = std::array<int, 2>{0, 0}, py::arg("radius"),
+      py::arg("fov") = std::array<double, 2>{0, 0}, py::arg("gamma") = 0);
+  mjsMesh.def(
+      "make_prism",
+      [](raw::MjsMesh* self, int nedge) {
+        double params[1] = {static_cast<double>(nedge)};
+        if (mjs_makeMesh(self, mjMESH_BUILTIN_PRISM, params, 1)) {
+          throw pybind11::value_error(mjs_getError(mjs_getSpec(self->element)));
+        }
+      },
+      py::arg("nedge"));
+  mjsMesh.def(
+      "make_plate",
+      [](raw::MjsMesh* self, std::array<int, 2>& resolution) {
+        double params[2] = {static_cast<double>(resolution[0]),
+                            static_cast<double>(resolution[1])};
+        if (mjs_makeMesh(self, mjMESH_BUILTIN_PLATE, params, 2)) {
+          throw pybind11::value_error(mjs_getError(mjs_getSpec(self->element)));
+        }
+      },
+      py::arg("resolution") = std::array<int, 2>{0, 0});
 
   // ============================= MJSPAIR =====================================
   mjSpec.def("delete", [](MjSpec& self, raw::MjsPair& obj) {

python/mujoco/specs_test.py

@@ -484,6 +484,14 @@ class SpecsTest(absltest.TestCase):
     # Check that the state is the same.
     np.testing.assert_array_equal(state1, state2)
 
+  def test_make_mesh(self):
+    spec = mujoco.MjSpec()
+    mesh = spec.add_mesh(name='wedge')
+    mesh.make_wedge(resolution=[25, 25], radius=1, fov=[90, 45], gamma=0)
+    model = spec.compile()
+    self.assertEqual(model.nmesh, 1)
+    self.assertEqual(model.nmeshvert, 25 * 25)
+
   def test_compile_errors_with_line_info(self):
     spec = mujoco.MjSpec()