Stucuk wrote:Mathematically correct is different from going against maths. Maths states what a 2D world is, Y is Height. A 3D world is just a 2D world with depth, which means logicaly Z is depth and not A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X or Y. Which is one reason you hear people calling
depth buffers "
z-buffers" and not "y-buffers".
Z-buffer is called depth since it extends from your camera origin and will always be depth regardless in which direction you look at, it reprisents depth of a 2-D image, which can be aligned along ANY axis, and it will be depth along that axis.
I suggest you read a bit on this subject:
http://en.wikipedia.org/wiki/Cartesian_plane In mathematical illustrations of two-dimensional Cartesian systems, the first coordinate (traditionally called the abscissa) is measured along a horizontal axis, oriented from left to right. The second coordinate (the ordinate) is then measured along a vertical axis, usually oriented from bottom to top.
For three-dimensional systems, mathematicians usually draw the z axis as vertical and pointing up, so that the x and y axes lie on an horizontal plane. There is no prevalent convention for the directions of these two axes, but the orientations are usually chosen according to the right-hand rule. In three dimensions, the names "abscissa" and "ordinate" are rarely used for x and y, respectively. When they are, the z-coordinate is sometimes called the applicate.
http://en.wikipedia.org/wiki/Cartesian_ ... dimensions Once the x- and y-axes are specified, they determine the line along which the z-axis should lie, but there are two possible directions on this line. The two possible coordinate systems which result are called 'right-handed' and 'left-handed'. The standard orientation, where the xy-plane is horizontal and the z-axis points up (and the x- and the y-axis form a positively oriented two-dimensional coordinate system in the xy-plane if observed from above the xy-plane) is called right-handed or positive.
So, if i choose the mathematically correct: XY ground (horisontal) and Z height and not Y for height it does not go "against maths" at all.
You can join that with this:
http://en.wikipedia.org/wiki/Flight_dynamics And you'll see how body dimensions are usually aligned along the axes:
* Pitch rotation about Y Body Axis
* Roll rotation about X Body Axis
* Yaw rotation about Z Body axis
All math based papers will match the Z = height notation, only game math specific related formulas have it different.
BOTH are correct, and i can give you a example of a very succesful gaming franchise which uses Z as "up" since 1997 and across many engines on many platforms they built for it: the grand theft auto series.
