OK, turns out that the zPosition property of the layers is important here. I was setting them to values like 100, and -100. That turns out to be way too small - the perspective/rotation transform I was applying to the 'behind' layers was swinging these layers into a zPosition that greatly exceeds these numbers. Changing to values like 1000 fixes the issue. It's a bit hard to get a feel for what these numbers mean - it must hugely depend on what sort of "camera field of view" (or whatever the right terminology is - focal length?) for the Core Animation 3D system.
Anyway, what I've learned is that the z values need to be big, and probably not terribly precise. --Graham On 26/07/2011, at 11:31 AM, Graham Cox wrote: > Hi David, > > > This sounds somewhat close to what I have already. My layer hierarchy is: > > > Root > | > ------------------------- > | | | > Rep1 Rep2 Rep3 > | | | > -------- -------- | > | | | | | > L1 L2 R1 R2 Text > > > Where L1, L2, R1 and R2 are custom CALayer subclasses that draw the coloured > bars, and Rep 1..3 are the replicator layers that provide the reflective > effect. (Sidenote: I'm pretty sure it's not possible to create the reflection > effect I want using a single rep layer, as each one is set to a different > perspective transform). > > The 3 replicator layers are siblings, where Rep3 which hosts the text is > added last and should therefore draw last, i.e. on top. (I've tested this > assumption by trying to move it elsewhere in the sublayers list using > -insertSublayer:atIndex: but this doesn't appear to change anything. > > I also found that the text is not just being overwritten by the replicator > layer's drawing - if I set its position to overlap the actual content (L1, > R1, etc) it is also drawn over by the main content, so it does seem to simply > be in the wrong place in the drawing order. > > One strange thing was that for a while, it started to work correctly, without > me doing anything, then some cycles of dev and debugging later elsewhere in > the code, reverted to this behaviour. The code I was working on was nothing > to do with the graphical layers at all. This suggests that maybe there's > something a bit random going on in establishing which layer gets to draw when. _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
