How to judge the direction and angle of photography through the projection of photos

Learn physics to understand the characteristics of light, and then learn stereo knowledge to understand the projection relationship. Judging the direction and angle of photography by photo projection may be inaccurate, and the angle of light is constantly changing. If you shoot in the same place, different projections will appear with the change of light. Photographers can also change the direction of light through some props, which increases the difficulty of accurately determining the direction and angle. Simple judgment can have a three-dimensional imagination. The key is creativity, not simply applying formulas. Thank you. .