问题
How can I calculate a point (X,Y) a specified distance away, on a rotated axis? I know what angle I'd like the point "moving" along (in degrees).
回答1:
x = cos(a) * d
y = sin(a) * d
where a is the angle and d is the distance.
If the trigonometry functions takes radians intead of degrees, you have to convert the angle by dividing by 180/pi.
回答2:
Convert to polar coordinates and then rotate the point through the angle you want:
x = r * cos( theta );
y = r * sin( theta );
Note: theta in radians ( deg = rad * 180 / pi )
More info on polar coordinates.
回答3:
Do you mean the 3d formulas? They are easy as well. But we need to know what's your convention for specifying the axis.
来源：https://stackoverflow.com/questions/1055062/how-to-calculate-a-point-on-a-rotated-axis