Storage::getHeightAt doesn't take in account which way the triangles are facing
This may result in errors when getting the terrain heights. https://gitlab.com/OpenMW/openmw/-/blob/master/components/esmterrain/storage.cpp#L497
This may result in errors when getting the terrain heights. https://gitlab.com/OpenMW/openmw/-/blob/master/components/esmterrain/storage.cpp#L497