Write directly to GLB from TGeometries (#6404)

Uses ASSIMP for gltf2 binary file output. Support triangle_uvs, vertex colors, vertex normals and material. Compression not supported.
isl-org · Nov 1, 2023 · ed962e4 · ed962e4
1 parent ad0edd0
commit ed962e4
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Showing 8 changed files with 371 additions and 7 deletions.
diff --git a/3rdparty/assimp/assimp.cmake b/3rdparty/assimp/assimp.cmake
@@ -26,7 +26,6 @@ ExternalProject_Add(
         -DCMAKE_CXX_FLAGS:STRING=${assimp_cmake_cxx_flags}
         -DBUILD_SHARED_LIBS=OFF
         -DCMAKE_INSTALL_PREFIX=<INSTALL_DIR>
-        -DASSIMP_NO_EXPORT=ON
         -DASSIMP_BUILD_ASSIMP_TOOLS=OFF
         -DASSIMP_BUILD_TESTS=OFF
         -DASSIMP_INSTALL_PDB=OFF

diff --git a/cpp/open3d/io/file_format/FileASSIMP.cpp b/cpp/open3d/io/file_format/FileASSIMP.cpp
@@ -71,6 +71,7 @@ void LoadTextures(const std::string& filename,
         if (mat->GetTextureCount(type) > 0) {
             aiString path;
             mat->GetTexture(type, 0, &path);
+
             // If the texture is an embedded texture, use `GetEmbeddedTexture`.
             if (auto texture = scene->GetEmbeddedTexture(path.C_Str())) {
                 if (texture->CheckFormat("png")) {
@@ -91,13 +92,10 @@ void LoadTextures(const std::string& filename,
                     if (image->HasData()) {
                         img = image;
                     }
-                }
-
-                else {
+                } else {
                     utility::LogWarning(
                             "This format of image is not supported.");
                 }
-
             }
             // Else, build the path to it.
             else {
@@ -122,7 +120,12 @@ void LoadTextures(const std::string& filename,
         }
     };
 
-    texture_loader(aiTextureType_DIFFUSE, maps.albedo);
+    // Prefer BASE_COLOR texture as assimp now uses it for PBR workflows
+    if (mat->GetTextureCount(aiTextureType_BASE_COLOR) > 0) {
+        texture_loader(aiTextureType_BASE_COLOR, maps.albedo);
+    } else {
+        texture_loader(aiTextureType_DIFFUSE, maps.albedo);
+    }
     texture_loader(aiTextureType_NORMALS, maps.normal);
     // Assimp may place ambient occlusion texture in AMBIENT_OCCLUSION if
     // format has AO support. Prefer that texture if it is preset. Otherwise,
@@ -415,7 +418,8 @@ bool ReadModelUsingAssimp(const std::string& filename,
         mat->Get(AI_MATKEY_SHEEN, o3d_mat.base_reflectance);
 
         mat->Get(AI_MATKEY_CLEARCOAT_THICKNESS, o3d_mat.base_clearcoat);
-        mat->Get(AI_MATKEY_CLEARCOAT_ROUGHNESS,
+        mat->Get(AI_MATKEY_CLEARCOAT_FACTOR, o3d_mat.base_clearcoat);
+        mat->Get(AI_MATKEY_CLEARCOAT_ROUGHNESS_FACTOR,
                  o3d_mat.base_clearcoat_roughness);
         mat->Get(AI_MATKEY_ANISOTROPY, o3d_mat.base_anisotropy);
         aiString alpha_mode;

diff --git a/cpp/open3d/t/io/ImageIO.h b/cpp/open3d/t/io/ImageIO.h
@@ -61,6 +61,10 @@ bool WriteImageToPNG(const std::string &filename,
                      const geometry::Image &image,
                      int quality = kOpen3DImageIODefaultQuality);
 
+bool WriteImageToPNGInMemory(std::vector<uint8_t> &output_buffer,
+                             const geometry::Image &image,
+                             int quality = kOpen3DImageIODefaultQuality);
+
 bool ReadImageFromJPG(const std::string &filename, geometry::Image &image);
 
 bool WriteImageToJPG(const std::string &filename,

diff --git a/cpp/open3d/t/io/TriangleMeshIO.cpp b/cpp/open3d/t/io/TriangleMeshIO.cpp
@@ -45,6 +45,7 @@ static const std::unordered_map<
                            const bool)>>
         file_extension_to_trianglemesh_write_function{
                 {"npz", WriteTriangleMeshToNPZ},
+                {"glb", WriteTriangleMeshUsingASSIMP},
         };
 
 std::shared_ptr<geometry::TriangleMesh> CreateMeshFromFile(

diff --git a/cpp/open3d/t/io/TriangleMeshIO.h b/cpp/open3d/t/io/TriangleMeshIO.h
@@ -58,6 +58,15 @@ bool ReadTriangleMeshFromNPZ(const std::string &filename,
                              geometry::TriangleMesh &mesh,
                              const open3d::io::ReadTriangleMeshOptions &params);
 
+bool WriteTriangleMeshUsingASSIMP(const std::string &filename,
+                                  const geometry::TriangleMesh &mesh,
+                                  const bool write_ascii,
+                                  const bool compressed,
+                                  const bool write_vertex_normals,
+                                  const bool write_vertex_colors,
+                                  const bool write_triangle_uvs,
+                                  const bool print_progress);
+
 bool WriteTriangleMeshToNPZ(const std::string &filename,
                             const geometry::TriangleMesh &mesh,
                             const bool write_ascii,