I’m experiencing a very strange behavior when using Planar reflections in a VR app. I had set the screen percentage to 25, because I did not need a high quality reflection on the marble floor. With this value I have a frame rate of 45 fps (more or less). I went crazy to understand why the fps wasn’t 90 and finally I tried to modify the Planar reflection’ settings. Among other things I also tried to improve the Screen Percentage to 100 and, magically, the frame rate has increased to 90 fps! If I just try to set it to 99, suddenly it kills the frame rate to 30-45 fps…
What I don’t understand is why the frame rate is higher when I set the screen percentage to 100. Theoretically it should do more work when the screen percentage is higher (theoretically…).
From the doc on Screen Percentage:
Downsample percent can be used to reduce GPU time rendering the planar reflection. This directly affects the quality of the reflection produced by the planar reflection.