Store model paths in assets.

This enables to preserve the paths of the child spec during `attach`.

PiperOrigin-RevId: 673349237
Change-Id: Ibf075c7ec037ff5d540bc60d6e77c12f60269791

doc/changelog.rst

@@ -72,6 +72,8 @@ Bug fixes
   integrators, wrong derivatives would be computed.
 - Fixed a bug in tendon wrapping around spheres. Before this fix, tendons that wrapped around spheres with an
   externally-placed :ref:`sidesite<spatial-geom-sidesite>` could jump inside the sphere instead of wrapping around it.
+- Fixed a bug that caused :at:`meshdir` and :at:`texturedir` to be overwritten during model
+  :ref:`attachment<meAttachment>.
 
 Python bindings
 ^^^^^^^^^^^^^^^

src/user/user_mesh.cc

@@ -72,6 +72,7 @@ extern "C" {
 
 namespace {
   using mujoco::user::VectorToString;
+  using mujoco::user::FilePath;
 }  // namespace
 
 // compute triangle area, surface normal, center
@@ -218,6 +219,14 @@ void mjCMesh::PointToLocal() {
 
 
 
+void mjCMesh::NameSpace(const mjCModel* m) {
+  mjCBase::NameSpace(m);
+  modelfiledir_ = FilePath(m->spec_modelfiledir_);
+  meshdir_ = FilePath(m->spec_meshdir_);
+}
+
+
+
 void mjCMesh::CopyFromSpec() {
   *static_cast<mjsMesh*>(this) = spec;
   file_ = spec_file_;
@@ -388,6 +397,14 @@ void mjCMesh::Compile(const mjVFS* vfs) {
     facenormal_.clear();
     facetexcoord_.clear();
 
+    // copy paths from model if not already defined
+    if (modelfiledir_.empty()) {
+      modelfiledir_ = FilePath(model->modelfiledir_);
+    }
+    if (meshdir_.empty()) {
+      meshdir_ = FilePath(model->meshdir_);
+    }
+
     // remove path from file if necessary
     if (model->strippath) {
       file_ = mjuu_strippath(file_);
@@ -402,8 +419,8 @@ void mjCMesh::Compile(const mjVFS* vfs) {
       throw mjCError(this, "unsupported content type: '%s'", asset_type.c_str());
     }
 
-    std::string filename = mjuu_combinePaths(model->meshdir_, file_);
-    resource = LoadResource(model->modelfiledir_, filename, vfs);
+    FilePath filename = meshdir_ + FilePath(file_);
+    resource = LoadResource(modelfiledir_.Str(), filename.Str(), vfs);
 
     // try loading from cache
     if (cache != nullptr && LoadCachedMesh(cache, resource)) {
@@ -2016,6 +2033,8 @@ void mjCSkin::NameSpace(const mjCModel* m) {
   for (auto& name : spec_bodyname_) {
     name = m->prefix + name + m->suffix;
   }
+  modelfiledir_ = FilePath(m->spec_modelfiledir_);
+  meshdir_ = FilePath(m->spec_meshdir_);
 }
 
 
@@ -2097,8 +2116,16 @@ void mjCSkin::Compile(const mjVFS* vfs) {
       throw mjCError(this, "Unknown skin file type: %s", file_.c_str());
     }
 
-    std::string filename = mjuu_combinePaths(model->meshdir_, file_);
-    mjResource* resource = LoadResource(model->modelfiledir_, filename, vfs);
+    // copy paths from model if not already defined
+    if (modelfiledir_.empty()) {
+      modelfiledir_ = FilePath(model->modelfiledir_);
+    }
+    if (meshdir_.empty()) {
+      meshdir_ = FilePath(model->meshdir_);
+    }
+
+    FilePath filename = meshdir_ + FilePath(file_);
+    mjResource* resource = LoadResource(modelfiledir_.Str(), filename.Str(), vfs);
 
     try {
       LoadSKN(resource);

src/user/user_objects.cc

@@ -50,6 +50,7 @@
 
 namespace {
 namespace mju = ::mujoco::util;
+using mujoco::user::FilePath;
 
 class PNGImage {
  public:
@@ -3402,6 +3403,14 @@ void mjCHField::CopyFromSpec() {
 
 
 
+void mjCHField::NameSpace(const mjCModel* m) {
+  mjCBase::NameSpace(m);
+  modelfiledir_ = FilePath(m->spec_modelfiledir_);
+  meshdir_ = FilePath(m->spec_meshdir_);
+}
+
+
+
 // destructor
 mjCHField::~mjCHField() {
   data.clear();
@@ -3514,8 +3523,16 @@ void mjCHField::Compile(const mjVFS* vfs) {
       throw mjCError(this, "unsupported content type: '%s'", asset_type.c_str());
     }
 
-    std::string filename = mjuu_combinePaths(model->meshdir_, file_);
-    mjResource* resource = LoadResource(model->modelfiledir_, filename, vfs);
+    // copy paths from model if not already defined
+    if (modelfiledir_.empty()) {
+      modelfiledir_ = FilePath(model->modelfiledir_);
+    }
+    if (meshdir_.empty()) {
+      meshdir_ = FilePath(model->meshdir_);
+    }
+
+    FilePath filename = meshdir_ + FilePath(file_);
+    mjResource* resource = LoadResource(modelfiledir_.Str(), filename.Str(), vfs);
 
     try {
       if (asset_type == "image/png") {
@@ -3631,6 +3648,14 @@ void mjCTexture::CopyFromSpec() {
 
 
 
+void mjCTexture::NameSpace(const mjCModel* m) {
+  mjCBase::NameSpace(m);
+  modelfiledir_ = FilePath(m->spec_modelfiledir_);
+  texturedir_ = FilePath(m->spec_texturedir_);
+}
+
+
+
 // free data storage allocated by lodepng
 mjCTexture::~mjCTexture() {
   data_.clear();
@@ -3960,7 +3985,7 @@ void mjCTexture::LoadFlip(std::string filename, const mjVFS* vfs,
     throw mjCError(this, "unsupported content type: '%s'", asset_type.c_str());
   }
 
-  mjResource* resource = LoadResource(model->modelfiledir_, filename, vfs);
+  mjResource* resource = LoadResource(modelfiledir_.Str(), filename, vfs);
 
   try {
     if (asset_type == "image/png") {
@@ -4176,12 +4201,12 @@ void mjCTexture::LoadCubeSeparate(const mjVFS* vfs) {
       }
 
       // make filename
-      std::string filename = mjuu_combinePaths(model->texturedir_, cubefiles_[i]);
+      FilePath filename = texturedir_ + FilePath(cubefiles_[i]);
 
       // load PNG or custom
       unsigned int w, h;
       std::vector<unsigned char> image;
-      LoadFlip(filename, vfs, image, w, h);
+      LoadFlip(filename.Str(), vfs, image, w, h);
 
       // PNG must be square
       if (w != h) {
@@ -4244,6 +4269,14 @@ void mjCTexture::LoadCubeSeparate(const mjVFS* vfs) {
 void mjCTexture::Compile(const mjVFS* vfs) {
   CopyFromSpec();
 
+  // copy paths from model if not already defined
+  if (modelfiledir_.empty()) {
+    modelfiledir_ = FilePath(model->modelfiledir_);
+  }
+  if (texturedir_.empty()) {
+    texturedir_ = FilePath(model->texturedir_);
+  }
+
   // buffer from user
   if (!data_.empty()) {
     if (data_.size() != nchannel*width*height) {
@@ -4299,13 +4332,13 @@ void mjCTexture::Compile(const mjVFS* vfs) {
     }
 
     // make filename
-    std::string filename = mjuu_combinePaths(model->texturedir_, file_);
+    FilePath filename = texturedir_ + FilePath(file_);
 
     // dispatch
     if (type==mjTEXTURE_2D) {
-      Load2D(filename, vfs);
+      Load2D(filename.Str(), vfs);
     } else {
-      LoadCubeSingle(filename, vfs);
+      LoadCubeSingle(filename.Str(), vfs);
     }
   }
 

src/user/user_objects.h

@@ -808,6 +808,10 @@ class mjCMesh_ : public mjCBase {
 
   mjCBoundingVolumeHierarchy tree_;   // bounding volume hierarchy
   std::vector<double> face_aabb_;     // bounding boxes of all faces
+
+  // paths stored during model attachment
+  mujoco::user::FilePath modelfiledir_;
+  mujoco::user::FilePath meshdir_;
 };
 
 class mjCMesh: public mjCMesh_, private mjsMesh {
@@ -823,6 +827,7 @@ class mjCMesh: public mjCMesh_, private mjsMesh {
 
   void CopyFromSpec(void);
   void PointToLocal(void);
+  void NameSpace(const mjCModel* m);
 
   // accessors
   const mjsPlugin& Plugin() const { return plugin; }
@@ -952,6 +957,10 @@ class mjCSkin_ : public mjCBase {
 
   int matid;                          // material id
   std::vector<int> bodyid;            // body ids
+
+  // paths stored during model attachment
+  mujoco::user::FilePath modelfiledir_;
+  mujoco::user::FilePath meshdir_;
 };
 
 class mjCSkin: public mjCSkin_, private mjsSkin {
@@ -1005,6 +1014,10 @@ class mjCHField_ : public mjCBase {
   std::string spec_file_;
   std::string spec_content_type_;
   std::vector<float> spec_userdata_;
+
+  // paths stored during model attachment
+  mujoco::user::FilePath modelfiledir_;
+  mujoco::user::FilePath meshdir_;
 };
 
 class mjCHField : public mjCHField_, private mjsHField {
@@ -1024,6 +1037,7 @@ class mjCHField : public mjCHField_, private mjsHField {
 
   void CopyFromSpec(void);
   void PointToLocal(void);
+  void NameSpace(const mjCModel* m);
 
   std::string File() const { return file_; }
 
@@ -1052,6 +1066,10 @@ class mjCTexture_ : public mjCBase {
   std::string spec_file_;
   std::string spec_content_type_;
   std::vector<std::string> spec_cubefiles_;
+
+  // paths stored during model attachment
+  mujoco::user::FilePath modelfiledir_;
+  mujoco::user::FilePath texturedir_;
 };
 
 class mjCTexture : public mjCTexture_, private mjsTexture {
@@ -1071,6 +1089,7 @@ class mjCTexture : public mjCTexture_, private mjsTexture {
 
   void CopyFromSpec(void);
   void PointToLocal(void);
+  void NameSpace(const mjCModel* m);
 
   std::string File() const { return file_; }
   std::string get_content_type() const { return content_type_; }

test/user/user_model_test.cc

@@ -17,6 +17,7 @@
 #include <array>
 #include <cmath>
 #include <cstddef>
+#include <memory>
 #include <string>
 #include <vector>
 
@@ -502,5 +503,47 @@ TEST_F(LengthRangeTest, LengthRangeThreading) {
   mj_deleteSpec(spec);
 }
 
+// ----------------------------- test modeldir  --------------------------------
+
+TEST_F(MujocoTest, Modeldir) {
+  static constexpr char cube[] = R"(
+  v -1 -1  1
+  v  1 -1  1
+  v -1  1  1
+  v  1  1  1
+  v -1  1 -1
+  v  1  1 -1
+  v -1 -1 -1
+  v  1 -1 -1)";
+
+  auto vfs = std::make_unique<mjVFS>();
+  mj_defaultVFS(vfs.get());
+  mj_addBufferVFS(vfs.get(), "meshdir/cube.obj", cube, sizeof(cube));
+
+  // child with the asset
+  mjSpec* child = mj_makeSpec();
+  mjsMesh* mesh = mjs_addMesh(child, 0);
+  mjsFrame* frame = mjs_addFrame(mjs_findBody(child, "world"), 0);
+  mjsGeom* geom = mjs_addGeom(mjs_findBody(child, "world"), 0);
+  mjs_setString(child->meshdir, "meshdir");
+  mjs_setString(mesh->file, "cube.obj");
+  mjs_setString(mesh->name, "cube");
+  mjs_setString(geom->meshname, "cube");
+  mjs_setFrame(geom->element, frame);
+  geom->type = mjGEOM_MESH;
+
+  // parent attaching the child
+  mjSpec* spec = mj_makeSpec();
+  mjs_setString(spec->meshdir, "asset");
+  mjs_attachFrame(mjs_findBody(spec, "world"), frame, "_", "");
+  mjModel* model = mj_compile(spec, vfs.get());
+  EXPECT_THAT(model, NotNull());
+
+  mj_deleteSpec(child);
+  mj_deleteSpec(spec);
+  mj_deleteModel(model);
+  mj_deleteVFS(vfs.get());
+}
+
 }  // namespace
 }  // namespace mujoco