Make mjs_findElement find meshes by file name.

PiperOrigin-RevId: 780150428
Change-Id: Ie500062fa8cca755683b66540e84ede588d7c331

python/mujoco/specs_test.py

@@ -984,13 +984,18 @@ class SpecsTest(absltest.TestCase):
     texture.data = np.zeros((2, 2, 3), dtype=np.uint8).tobytes()
     spec.compile()
 
-  def test_find_unnamed_texture(self):
+  def test_find_unnamed_asset(self):
     spec = mujoco.MjSpec()
     texture_file = spec.add_texture(file='file.png')
     texture_name = spec.add_texture(name='name')
+    mesh_file = spec.add_mesh(file='file.obj')
+    mesh_name = spec.add_mesh(name='mesh')
     self.assertEqual(spec.texture('file'), texture_file)
     self.assertEqual(spec.texture('name'), texture_name)
+    self.assertEqual(spec.mesh('file'), mesh_file)
+    self.assertEqual(spec.mesh('mesh'), mesh_name)
     self.assertIsNone(spec.texture('none'))
+    self.assertIsNone(spec.mesh('none'))
 
   def test_attach_units(self):
     child = mujoco.MjSpec()

src/user/user_api.cc

@@ -910,7 +910,9 @@ mjsElement* mjs_findElement(mjSpec* s, mjtObj type, const char* name) {
     case mjOBJ_FRAME:
       return model->FindTree(model->GetWorld(), type, std::string(name));  // recursive search
     case mjOBJ_TEXTURE:
-      return model->FindTexture(std::string(name));  // check filename too
+      return model->FindAsset(std::string(name), model->Textures());  // check filename too
+    case mjOBJ_MESH:
+      return model->FindAsset(std::string(name), model->Meshes());  // check filename too
     default:
       return model->FindObject(type, std::string(name));  // always available
   }

src/user/user_model.cc

@@ -1338,19 +1338,25 @@ static T* findobject(std::string_view name, const vector<T*>& list, const mjKeyM
 
 
 
-mjCBase* mjCModel::FindTexture(std::string_view name) const {
-  for (unsigned int i=0; i < textures_.size(); i++) {
-    if (textures_[i]->name == name) {
-      return textures_[i];
+template <class T>
+mjCBase* mjCModel::FindAsset(std::string_view name, const std::vector<T*>& list) const {
+  for (unsigned int i=0; i < list.size(); i++) {
+    if (list[i]->name == name) {
+      return list[i];
     }
-    if (textures_[i]->name.empty() &&
-        std::filesystem::path(textures_[i]->spec_file_).filename().stem() == name) {
-      return textures_[i];
+    if (list[i]->name.empty() &&
+        std::filesystem::path(list[i]->spec_file_).filename().stem() == name) {
+      return list[i];
     }
   }
   return nullptr;
 }
 
+template mjCBase* mjCModel::FindAsset<mjCTexture>(
+    std::string_view name, const std::vector<mjCTexture*>& list) const;
+template mjCBase* mjCModel::FindAsset<mjCMesh>(
+    std::string_view name, const std::vector<mjCMesh*>& list) const;
+
 
 
 // find object in global lists given string type and name

src/user/user_model.h

@@ -246,12 +246,15 @@ class mjCModel : public mjCModel_, private mjSpec {
   mjCDef* FindDefault(std::string name);                            // find defaults class name
   mjCDef* AddDefault(std::string name, mjCDef* parent = nullptr);   // add defaults class to array
   mjCBase* FindObject(mjtObj type, std::string name) const;         // find object given type and name
-  mjCBase* FindTexture(std::string_view name) const;                // find texture given name
   mjCBase* FindTree(mjCBody* body, mjtObj type, std::string name);  // find tree object given name
   mjSpec* FindSpec(std::string name) const;                         // find spec given name
   mjSpec* FindSpec(const mjsCompiler* compiler_);                   // find spec given mjsCompiler
   void ActivatePlugin(const mjpPlugin* plugin, int slot);           // activate plugin
 
+  // find asset given name checking both name and filename
+  template <class T>
+  mjCBase* FindAsset(std::string_view name, const std::vector<T*>& list) const;
+
   // accessors
   std::string get_meshdir() const { return meshdir_; }
   std::string get_texturedir() const { return texturedir_; }