So you have a picture from a floor where you would like to place a 2d illustration? Here's what I would do: camera calibration to place the camera correctly in relation to the floor and scale the scene.
Get the exif info from the photograph, camera mode/sensor sizel, lens FOV
Undistort the image (straight lines make for better calibration)
Load the image in C4D through the camera calibration tag
Place X, Y, Z axis or a plane and an origin point
Estimate the length of one line to scale the scene (you did measure things in the scene right?)
Solve the camera
Place a plane on the floor and combine it with the image texture of the illustration
Adjust light and render
I do find this whole process a bit fiddly, it is never a perfect solve. Lenses focal point not being exactly what they state especially the zoom versions.
See also this usefull explanation: