To create 3d graphism i use a formula that convert a 3d point into a 2d point that i can draw on the screen.
Now how can i do the inverse ? : convert a 2d point into a 3d point.
Here is the formula :
d and r are focal parameters.
n and n1 are used to center the drawing on the form.
(I use : d=2000, r=2000, n=400, n1=400)
xe and ye are the coordinates and the result of the formula.
x,y and z are the 3d coordinates of the point.
d,r,n and n1 are known.