I have a particle effect using a text as a custom particle. The text is in a separate comp. I'm using the "scale over life" setting to cause the particles to get bigger towards the end of their life. Everything works real nice, but I'm seeing a steppiness to the scaling. It's not smooth. I've tried field rendering, and frame rendering. No difference. I was wondering if anyone has seen something like this from particular?
Are you playing with PTF or anything? If so, the changed sampling behavior could be the reason. Also: Maybe your particle lifespan is too short, causing interpolation steps to be much larger towards the end? Other than that, I've never experienced any such oddities so far...
If particle life is very long and sizes are big there may be visible resolution problems with the Size over Life control. Try if possible using shorter lived particles, or try to adjust the curve (I know it's hard to do with precision).