diff --git a/src/libslic3r/Format/OBJ.cpp b/src/libslic3r/Format/OBJ.cpp
index 0433e917c..abaae3692 100644
--- a/src/libslic3r/Format/OBJ.cpp
+++ b/src/libslic3r/Format/OBJ.cpp
@@ -36,12 +36,25 @@ bool load_obj(const char *path, TriangleMesh *meshptr, ObjInfo& obj_info, std::s
     bool exist_mtl = false;
     if (data.mtllibs.size() > 0) { // read mtl
         for (auto mtl_name : data.mtllibs) {
-            boost::filesystem::path full_path(path);
-            std::string             dir = full_path.parent_path().string();
-            auto                    mtl_file = dir + "/" + mtl_name;
-            boost::filesystem::path mtl_path(mtl_file);
-            auto                    _mtl_path = mtl_path.string().c_str();
-            if (boost::filesystem::exists(mtl_path)) {
+            if (mtl_name.size() == 0){
+                continue;
+            }
+            exist_mtl = true;
+            bool                    mtl_name_is_path = false;
+            boost::filesystem::path mtl_abs_path(mtl_name);
+            if (boost::filesystem::exists(mtl_abs_path)) {
+                mtl_name_is_path = true;
+            }
+            boost::filesystem::path mtl_path;
+            if (!mtl_name_is_path) {
+                boost::filesystem::path full_path(path);
+                std::string             dir = full_path.parent_path().string();
+                auto                    mtl_file = dir + "/" + mtl_name;
+                boost::filesystem::path temp_mtl_path(mtl_file);
+                mtl_path = temp_mtl_path;
+            }
+            auto    _mtl_path = mtl_name_is_path ? mtl_abs_path.string().c_str() : mtl_path.string().c_str();
+            if (boost::filesystem::exists(mtl_name_is_path ? mtl_abs_path : mtl_path)) {
                 if (!ObjParser::mtlparse(_mtl_path, mtl_data)) {
                     BOOST_LOG_TRIVIAL(error) << "load_obj:load_mtl: failed to parse " << _mtl_path;
                     message = _L("load mtl in obj: failed to parse");
@@ -52,7 +65,6 @@ bool load_obj(const char *path, TriangleMesh *meshptr, ObjInfo& obj_info, std::s
                 BOOST_LOG_TRIVIAL(error) << "load_obj: failed to load mtl_path:" << _mtl_path;
             }
         }
-        exist_mtl = true;
     }
     // Count the faces and verify, that all faces are triangular.
     size_t num_faces = 0;
diff --git a/src/libslic3r/Format/objparser.cpp b/src/libslic3r/Format/objparser.cpp
index c56d6930c..82bf2b496 100644
--- a/src/libslic3r/Format/objparser.cpp
+++ b/src/libslic3r/Format/objparser.cpp
@@ -237,7 +237,7 @@ static bool obj_parseline(const char *line, ObjData &data)
 				}
 			}
 			if (vertex.coordIdx < 0)
-                vertex.coordIdx += (int)data.coordinates.size() / 4;
+                vertex.coordIdx += (int) data.coordinates.size() / OBJ_VERTEX_LENGTH;
             else
 				-- vertex.coordIdx;
 			if (vertex.normalIdx < 0)
@@ -604,9 +604,6 @@ bool objparse(const char *path, ObjData &data)
     	BOOST_LOG_TRIVIAL(error) << "ObjParser: Out of memory";
 	}
 	::fclose(pFile);
-
-	// printf("vertices: %d\r\n", data.vertices.size() / 4);
-	// printf("coords: %d\r\n", data.coordinates.size());
 	return true;
 }
 
@@ -646,9 +643,6 @@ bool mtlparse(const char *path, MtlData &data)
         BOOST_LOG_TRIVIAL(error) << "MtlParser: Out of memory";
     }
     ::fclose(pFile);
-
-    // printf("vertices: %d\r\n", data.vertices.size() / 4);
-    // printf("coords: %d\r\n", data.coordinates.size());
     return true;
 }