fusion layering question

for the most part i do this kind of thing directly in editing programs without issue. i now want to use this technique in something more complex so i want to move into fusion. i haven't been able to figure out the layering logic, though.

in an editing program i can animate the crop of an image to, say, wipe the image on vertically from the center and wipe it off horizontally back to the center. makes for a nice visual rhythm. the whole thing might last 48 frames. i can then duplicate the clip several times on top of itself, each time staggering by, maybe, 3 frames. this creates a kind of cascading effect that's easy to control by sliding the sync of each duplicated clip. when i try to do this in fusion, though, the layering messes up.

i found that the fusion crop tool seems very different than what an editor would call crop, but was able to animate the rectangle mask to replicate the wipe on/off behavior. this gives me a rectangle node feeding a loader node for my running footage. when i try duplicating the pair of nodes, though, i get unexpected behavior. what i did was to duplicate the pair of nodes, then i went to the timeline and staggered the two pairs by 3 frames. then, back in the flow pane, i merged the two pairs into a single output. this is where i see the issue.

unlike in an editor, the two 'layers' appear to switch layering position. depending on how i patch the fg/bg in the merge node, either the fg or bg is obscured by one of the node-pairs. my cascade effect, if visible at the start of the clip, is covered over at the end. if covered at the start of the clip, it is visible at the end. the only way, which wasn't very seamless, that i could figure out to get around this has been to split the merge node into two merge nodes with the fg/bg swapped, one handling the start and the other handling the end.

there must be a simpler way to achieve this but i'm way too new to fusion to have figured it out. any tips welcomed.

thanks,
g

First question before I get into the actual tips: are you using Fusion Studio or Free? (for each version I could recommend a slightly different approach)

thankyou, sander. for now, i'm using free. that could change once i figure out how to do some of these things i've been posting about but, for now, i'm asking about free.

thanks again,
g