drawing a sphere

[shiva kiran]

Consider a point in 3D <x,y,z> as origin . I want to draw an ellipse for that I need to get <x',y',z'> coordinates given some radius .

Can any one write a function or give some mathematical equations for these.

[krtxmrtz]

Consider a point in 3D <x,y,z> as origin . I want to draw an ellipse for that I need to get <x',y',z'> coordinates given some radius .

Can any one write a function or give some mathematical equations for these.

The equation of an ellipse with origin at (x,y,z) is

[(x' - x)/a]² + [(y' - y)/b]² + [(z' - z)/c]² = 1

where a, b and c are the semiaxes. If you make a = b = c = r (radius) then the eqution simplifies to the case of a sphere:

[(x' - x)/r]² + [(y' - y)/r]² + [(z' - z)/r]² = 1

or

(x' - x)² + (y' - y)² + (z' - z)² = r²