[backport Humble] load glb meshes (ros-visualization#1154)

Signed-off-by: Alejandro Hernández Cordero <ahcorde@gmail.com>

Author: ahcorde

rviz_rendering/CMakeLists.txt

@@ -106,6 +106,12 @@ target_link_libraries(rviz_rendering
   resource_retriever::resource_retriever
 )
 
+if("${assimp_VERSION}" VERSION_GREATER 4.1.0)
+  target_compile_definitions(rviz_rendering PRIVATE ASSIMP_VERSION_5)
+else()
+  message("Warning, assimp below 4.10 detected, disable embedded texture")
+endif()
+
 target_include_directories(rviz_rendering
   PUBLIC
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>

rviz_rendering/src/rviz_rendering/mesh_loader_helpers/assimp_loader.cpp

@@ -82,7 +82,7 @@ class ResourceIOStream : public Assimp::IOStream
     memcpy(buffer, pos_, to_read);
     pos_ += to_read;
 
-    return to_read;
+    return to_read / size;
   }
 
   size_t Write(const void * buffer, size_t size, size_t count) override
@@ -262,6 +262,7 @@ std::vector<Ogre::MaterialPtr> AssimpLoader::loadMaterials(
       Ogre::ColourValue(0, 0, 0, 1.0));
 
 
+    SetScene(scene);
     setLightColorsFromAssimp(resource_path, mat, ai_material, material_internals);
 
     setBlending(mat, ai_material, material_internals);
@@ -274,6 +275,11 @@ std::vector<Ogre::MaterialPtr> AssimpLoader::loadMaterials(
   return material_table_out;
 }
 
+void AssimpLoader::SetScene(const aiScene * ai_scene)
+{
+  this->ai_scene_ = ai_scene;
+}
+
 void AssimpLoader::setLightColorsFromAssimp(
   const std::string & resource_path,
   Ogre::MaterialPtr & mat,
@@ -290,11 +296,24 @@ void AssimpLoader::setLightColorsFromAssimp(
       uint32_t uv_index;
       ai_material->GetTexture(aiTextureType_DIFFUSE, 0, &texture_name, &mapping, &uv_index);
 
+      std::string texture_path;
+#ifdef ASSIMP_VERSION_5
+      const aiTexture * texture = this->ai_scene_->GetEmbeddedTexture(texture_name.C_Str());
+      if (texture == nullptr) {
+#endif
+      // It's not an embedded texture. We have to go find it.
       // Assume textures are in paths relative to the mesh
       QFileInfo resource_path_finfo(QString::fromStdString(resource_path));
       QDir resource_path_qdir = resource_path_finfo.dir();
-      std::string texture_path = resource_path_qdir.path().toStdString() + "/" + texture_name.data;
+      texture_path = resource_path_qdir.path().toStdString() + "/" + texture_name.data;
       loadTexture(texture_path);
+#ifdef ASSIMP_VERSION_5
+    } else {
+      // it's an embedded texture, like in GLB / glTF
+      texture_path = resource_path + texture_name.data;
+      loadEmbeddedTexture(texture, texture_path);
+    }
+#endif
       Ogre::TextureUnitState * tu = material_internals.pass_->createTextureUnitState();
       tu->setTextureName(texture_path);
     } else if (propKey == "$clr.diffuse") {
@@ -340,6 +359,35 @@ void AssimpLoader::setLightColorsFromAssimp(
   }
 }
 
+void AssimpLoader::loadEmbeddedTexture(
+  const aiTexture * texture, const std::string & resource_path)
+{
+  if (texture == nullptr) {
+    RVIZ_RENDERING_LOG_ERROR_STREAM("null texture!");
+    return;
+  }
+
+  // use the format hint to try to load the image
+  std::string format_hint(
+    texture->achFormatHint,
+    strnlen(texture->achFormatHint, sizeof(texture->achFormatHint)));
+
+  Ogre::DataStreamPtr stream(
+    new Ogre::MemoryDataStream(
+      (unsigned char *)texture->pcData, texture->mWidth));
+
+  try {
+    Ogre::Image image;
+    image.load(stream, format_hint.c_str());
+    Ogre::TextureManager::getSingleton().loadImage(
+      resource_path, ROS_PACKAGE_NAME, image);
+  } catch (Ogre::Exception & e) {
+    RVIZ_RENDERING_LOG_ERROR_STREAM(
+      "Could not load texture [" << resource_path.c_str() <<
+        "] with format hint [" << format_hint << "]: " << e.what());
+  }
+}
+
 void AssimpLoader::loadTexture(const std::string & resource_path)
 {
   if (!Ogre::TextureManager::getSingleton().resourceExists(resource_path, ROS_PACKAGE_NAME)) {

rviz_rendering/src/rviz_rendering/mesh_loader_helpers/assimp_loader.hpp

@@ -103,6 +103,14 @@ class AssimpLoader
 
   std::vector<Ogre::MaterialPtr> loadMaterials(
     const std::string & resource_path, const aiScene * scene);
+
+  void SetScene(const aiScene * ai_scene);
+  const aiScene * ai_scene_;
+
+  void loadEmbeddedTexture(
+    const aiTexture * ai_texture,
+    const std::string & resource_path);
+
   void setLightColorsFromAssimp(
     const std::string & resource_path,
     Ogre::MaterialPtr & mat,