Fixed frame rate not staying fixed?

My game requires advanced physics, so I have enabled fixed frame rate in the project settings.

But sometimes it doesn’t stay fixed! It instead will change rapidly! As low as 15 fps, all the way up to 160 fps! Depending on how complex the environment is. And this causes the game to run in slow or fast motion. The frame will eventually start staying fixed, but there doesn’t seem to be any pattern to it.

What’s up with this?

did you ever figure this out? or some workaround? i have problems with fixed frame rate too.
very important to my workflow, and it just stopped working.

Hi. No, I actually haven’t used this engine at all in awhile. Just too busy with other things.

I will tell you this, though: It’s quite uncommon for games to have a “fixed frame rate” these days. The main reason I wanted to use it was because I was confused about programing for any frame rate, and also I wanted to test physics at various different frame rates to make sure everything was consistent.

But it turns out there was actually a better way for me to test that: Some function that set’s the frame rate to a value I specify. Very useful for testing. I don’t remember what it was exactly, something like “set target frame rate” or " set max fps" or something like that. Oh, and you might have to disable “v-sync” for it to actually work.

Try “googling” that stuff if it sounds like what you need. But if you’re sure you need to fix physics to frame rate, I still have no idea how to make it work. ¯_(ツ)_/¯