So, we want to transform x, y and z to new coordinates x'=(d x)/(z+d) and y'=(d y) /(z+d).

=d2*a2/(c2+d2)

so type this formula (on the above line) into E2 and hit return. You should now see -1.875.

Since d is in the d2 box, x is in the a2 box, and z is in the c2 box, we see that the Excel formula that we just typed in -

=d2*a2/(c2+d2)

is the correct formula to use in order to find the 2-D perspective coordinates of the given 3-D point, since it corresponds to the formula

x'=(d x)/(z+d)

Your mouse should now be a thin cross when you take it to your picture. We want to connect the dots to make the picture represented here. |