While trying to understand different coordinate systems I came across this website, which states:
RenderMan uses left-handed coordinate system
and the positive rotation is clockwise
, while OpenGL uses right-handed coordinate system
and the positive rotation is counter-clockwise
.
My question is whether the rotation direction and the coordinate system handedness are just two distinct conventions or this results from maths itself ?
Similarly, I know that the front facing vertices of triangles have to be ordered in counter-clokwise
direction in OpenGL. Does this too relate to coordinate system handedness or it's just another unrelated convention ?
And thirdly, when a picture of random coordinate system with axes labeled as x, y, z
is thrown before me, how do I tell which one is left handed and which one is right handed ?
I know there is a rule with right hand and the middle and the index fingers and the thumb, but everyone seems to use it differently. How should I align my fingers with these axes ?
Sorry for probably mixing a lot of unrelated stuff together, but after reading all kinds of internet sources, things start to blend together in my head.