Last week I wrote about Big Image Recorder, a plugin for Unity Recorder that captures massive renders of your scene. Though Recorder’s docs make no mention of it, creating a plugin is straightforward.1
If you want to make your own, I knocked together a starter project with a minimal implementation. It takes a camera and saves the frames as an image sequence. Recorder already outputs image sequences, and with more options, but you can use this bare-bones package as a jumping-off point to extend its functionality.
It helps that you can view Recorder’s source code. There’s no public repository, but you can peruse the C# after adding the package to your project. ↩