It broke with all the traditions of OpenGL, SGI, and even traditional mathematics in general. It was an arbitrary decision with deep impact, as you see here.
Ultimately, Microsoft wanted to differentiate themselves from the competition and set some standards, so they chose to go with a left-handed system for Direct3D (an early part of the DirectX suite). For example, electrical flow and magnetism are described in textbooks assuming the user will work with the right hand rule. They follow centuries of mathematics tradition that came from observing the natural world. You can't fix this distinction with a simple 'rotate ninety degrees' because no combination of rotations will align the two systems.īlender and OpenGL use a 'right handed' coordinate system. There is a fundamental difference between Blender and Unity's coordinate system, which incidentally is the same fundamental difference between Microsoft DirectX and OpenGL.
