I've got a fairly simple comp containing only five layers. The top four are embedded comps, with the bottom layer being a plane with an animated fractal noise effect. If I hide the top layers and leave only the plane visible so I can test my fractal noise settings, the RAM preview doesn't behave properly. It appears to make the preview all right, but playing it back isn't smooth at all. It's just as stuttery as the un-previewed parts of the comp. However, once I un-hide even one of the other comp layers above it and RAM preview again, the preview plays back smoothly. Has anyone encountered this before? I've done plenty of tests with animated fractal noise layers, and I don't recall ever having this problem playing back a RAM preview of one.
This is happening in HitFilm Express 2017 version 5.0.0121 (Update 7) running on a Mac Mini, OS X Yosemite, 8GB RAM.
If anyone wants to test this, I'm using the Fluid fractal noise type, all default settings, except I have the Seed keyframed to go from 4500 to 4502 over 8 seconds. I tried changing to other fractal noise types, and while some of them had less lag than others, they all weren't perfectly smooth unless one of the upper layers was also visible when generating the RAM preview. I even copied that plane layer into a brand new comp all by itself, but it exhibited the same behavior. However, once I added a grade layer above it, its RAM preview played smoothly.