I wrote a feedback filter in CoreImage format, using CIImageAccumulator to hold data across frames. The compiled filter works great in Quartz Composer but when I load it Modul8 it renders transparent (and it seems like RGB values are also 0)
I stripped down the filter to remove all the complexity. Returning the input image works, but writing it into the accumulator then returning that fails in the same way. This simple passthrough test again works fine in QC.