TiAm wrote:FYI to everyone: debug readings are not to be trusted. If you really want to run comparisons, make a spritefont readout and populate it with fps/cpu/objCount/etc.
Anyway: When I experimented with this back a few months ago, my impression was that 'on collision' and 'is overlapping' tended to be similar to each other vis-a-vis CPU usage. However, when pushed really hard (bullet hell shooter with thousands of bullets), 'is overlapping' had pretty consistent performance, whereas 'on collision' seemed to cause more instances of stutter and slowdown, even if the average CPU/FPS was the same.
I know that the readings are not 100% accurate, but I don't see the huge importance in that, as stated earlier, its not that important whether its 90.1% CPU Util or 91.3%. But that you can and will see a difference in performance and a severe FPS drop, which you don't have to measure really because you can see everything is lagging around.
According to the r155 collision changes that someone posted earlier, not all of it seems to be working as stated there. It says that for optimal performance it is suggested that you put "Is overlapping" before any other picking condition to avoid C2 having to brute force collision checks. However in another program I made for testing collision, I get better performance (10-13 FPS improvement) when putting "Is overlapping" as the last condition, after Im done with the picking conditions, which should make it brute force and therefore give worse performance, but its the exact opposite from my experience at least. And that test is with 1700-2000 moving objects, so 10-13 fps is not a small increase.
(After running it again, its actually more like 17-23 fps with 1740 object)