This process involves several steps. First of all, you need to match the camera. It´s position, angle and focal length. Then the lighting. Using HDRI is the best way to mimic real world lighting. Also, take note of where the sun is in your shot (or any other light sources for that matter). That´s what you can do in 3D. The rest is actually postworking with the layers.

You need to match the color-scale, brightness, contrast and softness. Live footage is often more fuzzy or blurry than 3D graphics. So you need to de-grade it so to speak. And add noise and imperfections. And that´s basically it!

Waldemar Belwon