Cutscene Cameras: Rule of 180

Pigeon Simulator features a rich story mod system that allows you to engage with, and run odd jobs for, many wacky in-game characters. To make conversations between characters more interesting, our game sports many different in-game cameras. We wanted to avoid the “RPG Staring Contest” where a conversation is just a static shot of one character’s face. But in sidestepping the freezer of static shots, we wound up in the frying pan of confusing camera transitions.

We borrowed a technique from cinematography called “The rule of 180” to mitigate these confusing camera changes. “The rule of 180” is a filmmaking guideline to maintain spatial continuity and orientation between characters or objects within a scene, ensuring the audience doesn't become disoriented. It establishes an imaginary line, called the "180-degree line" or "axis of action," that runs through the main subjects in a scene, such as two characters in a conversation. The camera should remain on one side of this line throughout the scene, maintaining consistent screen direction and spatial relationships between subjects. Violating the 180-degree rule can result in disorienting "jumps" in the scene, making it difficult for the audience to follow the action and disrupting their immersion.

As you can see, the two images above obey “The rule of 180“. In both shots Pidge is to the left side of the camera and LeonardDoveVinci is to the right.

In the two images above, “The Rule of 180“ is broken. In the top photo Leonard Dove Vinci is the right of the shot, while in the bottom photo he is to the left. This creates a jarring effect for the viewer.

Once we’d established how to make scenes feel easier for the player to follow, our next step was to make sure “The Rule of 180“ was respected during camera transitions. Luckily, the plugin we were using Cinemachine helped to streamline the process. By using an Orbital Transposer Body we were able to make our camera rotate around the subjects with ease. We merely had to specify whether an acceptable range around the subjects was from 0 to 180, or from 0 to -180.

From there, we wanted to give story mod writers an opportunity to break “The Rule of 180“ for dramatic effect. So we added a story mod command that would allow a writer to “flip“ the camera so that the acceptable range was inverted. If cameras were orbiting from 0 to 180 degrees, they would instead orbit from 0 to -180 degrees.

We had to make sure this worked with all of our cutscene cameras including wide shot cameras, focus cameras and group shot cameras. Luckily, we had test dialog that made it quick for us to test and iterate here.

The new system is a huge improvement, but it will be up to our designers to tweak our cinemachine variables so that the shots look just right.