[BenBernard]

Understood...but the math is the same no matter where you get your measurements. We do all (or most of) the math in our robot code, reading values from NetworkTables which be populated by GRIP on the driver station, GRIP on the roborio, or our opencv-based tracker on a raspberry pi.

You need to separate out the problem and focus on the parts separately. GRIP won't tell you distance--but neither will OpenCV. Both will tell you height, width, center X and center Y. You will need to determine the distance to the target based on those inputs, as described in the linked thread.