I have a problem where i have a sphere and 1 point that can be anywhere on that sphere's surface. The Sphere is at the center point (0,0,0).
I now need to get 2 new points, 1 just a little below the and another little above this in reference to the Y axis. If needed or simpler to solve, the points can be about 15º above and below the original point, this viewing the movement on a 2D circle.
Thank you in advance for any given help.
This is to be used on a world globe where the selected point will never be on the top or bottom.
I'm using the latitude and longitude suggested by rlgordonma and user1551
what I'm doing is adding and subtracting a fixed value to ϕ
These 2 apear correctly, at least they apear to look in place: The original point is in the middle of the 2 bars. The sphere has R=1 all the coords i'm putting here are rounded because they are to big (computer processed)
coord: (0.77, 0.62, 0,11)
coord: (0.93, -0.65, 0.019)
coord: (-0.15, 0.59, 0.79)
coord: (-0.33, 0.73, -0.815)
there are other occasions for both but i didn't want to put all here.
R = 1 φ = arctan(y/x) θ = arccos(z/1) //to move up only one is used φ = φ + π/50 //to move down only one is used φ = φ - π/50 (x,y,z)=(sinθ cosφ, sinθ sinφ, cosθ)