I use a second camera in my scene to output to a render texture, and I show the content in the corner of the screen. Even with no post processing or anything fancy on that second camera, it has a significant impact on framerate when it’s enabled. With just the main camera rendering at 1920x1080, I’m getting 120-130 FPS in a test scene. When I enable the second camera, it drops to about 80-90 FPS. Some details:
- I’ve turned off all global volumes, so the second camera is as bare-bones as I can make it.
- The second camera only uses a single layer for culling
- It’s rendering into a 512x512 render texture. But I’ve dropped that to 16x16 for testing with no improvement to performance.
- No anti-aliasing or other effects/post-processing on the camera
I understand that rendering a camera isn’t a trivial thing. But I end up intentionally distorting this render texture later, to give it a poorer quality, and I’d be fine with a lower quality render, if possible. Anyway, it’s probably not possible, but I wondered if there was anything else I could do to get a fairly cheap render off the secondary camera (without affecting the main camera.)
