I got some reports that the camera could feel choppy in The End of Dyeus, so I did some testing, which led me to finding this pretty odd behavior: when the camera horizontal angle is diagonal (45°, 135°...) it looks like automatic frustum culling doesn't work.
Here's a video to help showcase the issue:
https://www.curious-planet.com/files/ir ... _issue.mp4
I've turned off the terrain to pinpoint the problem, but the behavior is the same when rendering the terrain alone. As you can see in the video, the game renders ~95 000 triangles in straight lines, and ~180 000 in diagonals; I've turned automatic culling off on trees on the last part of the video, and you can see that the game renders ~175 000 triangles in most direction, and ~180 000 in diagonals (the 5000 tris difference is due to vegetation and visual effects like the sky, etc, which still have automatic culling on). So it matches the diagonal values with automatic culling turned on.
Sorry if this is a known issue, I've searched the forum before posting but I might have missed it.
Please note that this has been tested in Irrlicht 1.8.4; here's the console output:
Hope this helps!