# Delete obsolete code and comment to make `get3DPoint` more understandable

Restructuring of `get3DPoint` to be more easily understood. See the following survey comment for the used approach of the code.

Since we change from `double` to `float` mid-calculation, I couldn't rewrite everything as I wanted without breaking tests.

``````/* Basic Idea:
* All points projecting onto a point on the image plane lie on the same
* line (cf. pinhole camera model). We can determine this line in the form:
*
* g: x = lambda * v
*
* This line exists in camera coordinates. Let v be the projection with
* depth 1 (i.e. v_3 = 1). Then lambda is the depth of the resulting point.
* We'll continue to call lambda z instead, to show this.
* We now want to determine the depth at which the resulting point has height h
* in world coordinates. The transformation from cam to world is:
*
* W = R * C - T
* W   := Point in World Coords
* C   := Point in Cam Coords
* R,T := Rotation and Translation of Cam
*
* By putting in our x = z * v, we get:
*     W          = R * (z * v) - T
* <=> W          = z * Rv - T
* <=> W + T      = z * Rv
* <=> (W + T)/Rv = z
* We select the third row of this to solve for z. Finally g(z) is transformed
* into World Coords.
*/``````

Closes #118 (closed)