enable file caching, currently only for Wavefront .obj files. You can disable file caching using

pybullet.setPhysicsEngineParameter(enableFileCaching=0)
Allow VR camera tracking only using position tracking, no orientation tracking (use
pybullet.setVRCamera([posX,posY,posZ],trackObjectFlag=0 or pybullet.VR_CAMERA_TRACK_OBJECT_ORIENTATION)

examples/ThirdPartyLibs/Wavefront/tiny_obj_loader.cpp

@@ -560,9 +560,12 @@ LoadObj(
 
   int maxchars = 8192;  // Alloc enough size.
   std::vector<char> buf(maxchars);  // Alloc enough size.
+  std::string linebuf;
+  linebuf.reserve(maxchars);
+
   while (ifs.peek() != -1) {
 
-    std::string linebuf;
+	linebuf.resize(0);
     safeGetline(ifs,linebuf);
 
     // Trim newline '\r\n' or '\r'