I came across the UE4’s Performance Guidelines for Mobile Devices. In the Additional Suggestions section near the bottom of the page it says: “Triangle count of the entire scene should be <= 500k for any view. This has been determined to be the maximum poly count that can hit 30fps on both iPad4 and iPad Air”.
I then did a test by running a simple level with nothing but a piece of terrain on an iPad Pro (11-inch 3rd gen) and checked the triangle count in the scene with “stat rhi” command (Triangles Drawn). It turned out that the scene had over a MILLION triangles. Then I moved the camera, made the terrain hidden from the view, and saw the count go down to a couple of thousands (which I believe came from skybox). Despite of the huge change on triangle count, frame rate only went down from 120fps to ~100fps. Frame rate capping was switching off. When the 30fps capping was on, fps did not change at all.
I am kinda OK with triangle count readings since I don’t see reasons to doubt them. However, I found it hard to explain why over-a-million triangles only dented frame rate by such a tiny amount on my ipad while the Performance Guidelines suggests that the impact should be much bigger.
Did anyone have similar experience in this “max triangle count” mystery?
