$ valgrind ./ray ../Scenes/scene03.json
==24501== Memcheck, a memory error detector
==24501== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==24501== Using Valgrind-3.14.0 and LibVEX; rerun with -h for copyright info
==24501== Command: ./ray ../Scenes/scene03.json
==24501==
Introduction to Computer Graphics - Raytracer

Unknown object type: "_sphere".
Parsed 8 objects.
Tracing...
terminate called after throwing an instance of 'std::bad_weak_ptr'
  what():  bad_weak_ptr
==24501==
==24501== Process terminating with default action of signal 6 (SIGABRT): dumping core
==24501==    at 0x4C5ED7F: raise (in /usr/lib/libc-2.28.so)
==24501==    by 0x4C49671: abort (in /usr/lib/libc-2.28.so)
==24501==    by 0x492F58D: __gnu_cxx::__verbose_terminate_handler() [clone .cold.1] (vterminate.cc:95)
==24501==    by 0x4935DF9: __cxxabiv1::__terminate(void (*)()) (eh_terminate.cc:47)
==24501==    by 0x4935E56: std::terminate() (eh_terminate.cc:57)
==24501==    by 0x49360AB: __cxa_throw (eh_throw.cc:95)
==24501==    by 0x13FEAD: std::__throw_bad_weak_ptr() (shared_ptr_base.h:84)
==24501==    by 0x14BEAB: _M_add_ref_lock (shared_ptr_base.h:247)
==24501==    by 0x14BEAB: __shared_count (shared_ptr_base.h:876)
==24501==    by 0x14BEAB: __shared_ptr<Object> (shared_ptr_base.h:1171)
==24501==    by 0x14BEAB: shared_ptr<Object> (shared_ptr.h:276)
==24501==    by 0x14BEAB: shared_from_this (shared_ptr.h:656)
==24501==    by 0x14BEAB: toPrimitives (object.h:28)
==24501==    by 0x14BEAB: Mesh::toPrimitives(std::vector<std::shared_ptr<Object>, std::allocator<std::shared_ptr<Object> > >&) (mesh.cpp:64)
==24501==    by 0x14AD5F: Scene::render(Image&) (scene.cpp:103)
==24501==    by 0x13D715: Raytracer::renderToFile(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&) (raytracer.cpp:129)
==24501==    by 0x1184B8: main (main.cpp:35)
==24501==
==24501== HEAP SUMMARY:
==24501==     in use at exit: 1,410,903 bytes in 18 blocks
==24501==   total heap usage: 94,564 allocs, 94,546 frees, 14,347,978 bytes allocated
==24501==
==24501== LEAK SUMMARY:
==24501==    definitely lost: 0 bytes in 0 blocks
==24501==    indirectly lost: 0 bytes in 0 blocks
==24501==      possibly lost: 136 bytes in 1 blocks
==24501==    still reachable: 1,410,767 bytes in 17 blocks
==24501==         suppressed: 0 bytes in 0 blocks
==24501== Rerun with --leak-check=full to see details of leaked memory
==24501==
==24501== For counts of detected and suppressed errors, rerun with: -v
==24501== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
Aborted (core dumped)