Reversing the Y coordinates

	Reversing the Y coordinates by Serge Marcotte (SSGGMM) on Jul 11, 2008 at 3:30:31 pm I'm exporting tracking data from PFTrack to AE. PFTrack doesn't normally allow this, so I'm simply exporting "human readable" tracking coordinates and pasting them into an AE-compatible text file. Works well, just one problem. PFTrack's zero coordinate for Y is on the bottom of the frame. AE's is on the top. Left and right are good, but up and down motion is reversed. I'd much rather avoid flipping the Y in AE, but I don't think I have any choice. Can it be done? (PFTrack doesn't seem to allow it.) Respond to this post   •   Return to posts index

	Re: Reversing the Y coordinates by Dave LaRonde on Jul 11, 2008 at 3:57:34 pm It sounds like you could do what you want through the use of an expression. Unfortunately, I stink at them. I'd check on the AE Expressions forum. Dave LaRonde Sr. Promotion Producer KCRG-TV (ABC) Cedar Rapids, IA Respond to this post   •   Return to posts index

	Re: Reversing the Y coordinates by Grant Swanson on Jul 11, 2008 at 4:05:40 pm I'm not quite sure I know exactly what you're trying to do, but try applying the tracking data from the text to a null object and simply place a minus sign (-) in front of the y value for either position or anchor point, depending on where your text applies it. The data will still be applied, but it will all be negative (only in the y-coordinates). Let me know if this works for you, or if I'm misunderstanding what you're doing. Grant Swanson Visual Effects Supervisor Video Apex videoapex.blogspot.com Respond to this post   •   Return to posts index

	Re: Reversing the Y coordinates by Serge Marcotte on Jul 11, 2008 at 4:27:18 pm In PFTrack, my 10-frame marker moves downward, therefore Y 10 to Y 1. PFTrack calls the bottom row of pixels Y 1. I bring that info into AE, and my null instead moves upwards, simply because AE calls the TOP row of pixels Y 1. I'm looking to make them match. Off the top, your idea sounds like a good one. But how do you stick a minus sign in there? If you try to select all your keys, then click the Y parameter and type "-" before the first number, every single key after that transforms into that first number. I'll try posting in Expressions, as suggested by Mr LaRonde. But if you can tell me how to put a minus in there properly, it's the first thing I'll try. Thanks. Respond to this post   •   Return to posts index

	Re: Reversing the Y coordinates by Darby Edelen on Jul 12, 2008 at 6:19:37 am You should be able to find a solution by parenting all of your tracked layers to a null and manipulating the Null in some fashion. My first suggestion would be to try parenting them to the Null and then scaling it to -100% on the Y-axis (leave the X axis set to 100%, you'll need to unlink them to do this). Then delete the Null. I think that should work. Darby Edelen Lead Designer Left Coast Digital Santa Cruz, CA Respond to this post   •   Return to posts index

	Re: Reversing the Y coordinates by Serge Marcotte on Jul 12, 2008 at 2:08:37 pm Mr Ebberts from the Expressions forum handed me this for the null's position parameter: [value[0],thisComp.height - value[1]] So far, seems to work like a charm. Respond to this post   •   Return to posts index