Rendering video in the client like a video editor

I’m building a 3D simulation/visualization tool with Unity and I want people to be able to export video of it. Unfortunately, screen recording isn’t an option because the visualization can get laggy. On the other hand, if its something less computationally intensive, it would be nice if the video could export quicker than having to wait the entire duration. The most important part is that the video not be laggy nor skip frames if the live visualization cant keep up.

Normally, FFMPEG is used for encoding the video for this kind of thing, but how can I make Unity’s frame time “dynamic” in this way? Or is there an entirely other way to go about doing this?

(btw, if you do know what I’m doing an I should be using FFMPEG for this, can you help me a little with how to do that? FFMPEGs documentation is like trying to do rocket science by only looking at the glossary)