Ray Tracer Equations

Given:
eye is at (x,y,z)
SphereA is at (Sx,Sy,Sz)
Radius = 3

Screen is set up as shown:

(TopLeft) (WidthVector)
0------------------------------------>
|
|
|(HeightVector)
|
|
|
V

TopLeft is (Cx,Cy,Cz)
WidthVector is [Wx,Wy,Wz]
heightVector is [Hx,Hy,Hz]

For each Pixel on the screen is an ordered pair (w,v)
where w numbers each horizontal pixel
and v numbers the verticle ones.

Show me an equation for the shortest distance to the sphere
for a ray coming from the eye through the
correlating spot on the view plane for every pixel.

If there is no intersection this should result in division by zero.

Good Luck

Come on!

Is nobody interested??

Surely this cant be too difficult. i did this in QBASIC as a Freshman in highschool.

The first step is to find the point on the view plane that corresponds to the ordered pair (w,v)

this is easy:
(assuming 800 by 600 screen rez.)


ViewX = TopLeft.x + (WidthVector.x * w/800) + (HeightVector.x * v/600)
ViewY = TopLeft.y + (WidthVector.y * w/800) + (HeightVector.y * v/600)
ViewZ = TopLeft.z + (WidthVector.z * w/800) + (HeightVector.z * v/600)


The point is (ViewX, ViewY, ViewZ)