Hey y'all,
I have a shot of a pan of a house whose sky is so blown out that it's 100% white. I had no problem keying out the sky and adding a replacement by tracking the FG plate, but I would like there to be some subtle parralax between the sky and the FG. Is there an expression or something I can use in order to make the sky track "slower" than the FG, yet using the tracker data that came from the FG?
Thanks in advance
you can simply multiply the expression that points to the track in whatever node you use to pcik up the tracking information.
Something like 'Tracker1.track1X*0.5' for the x value in the Stabilize/Pan/Move2D node will make the track move at 50% speed but also offset the whole thing horizontally so you might have to apply an extra Pan node to shift it back where you need it.
Do the same thing for yPan and you should be set.
There
An example:
CODE
ADD_MOTION_TO = ColorWheel(720, 576, 2, 0, 1, 1, 1);
TAKE_MOTION_FROM = Checker(720, 576, 2, 32, xSize/GetDefaultAspect());
Stabilize1 = Stabilize(ADD_MOTION_TO, 1, 1, "1 point", Tracker1.track1X*0.5,
Tracker1.track1Y*0.5, 1, 1, 2*width/3, height/3, 0, 0, 2*width/3,
2*height/3, width/3, 2*height/3, "default", xFilter, "trsx",
0, 0.5, 0, 1, 1, 0, 0.938, "v2.0", 1, "1/64", "luminance",
0.3, 0.59, 0.11, 0.75, "use start frame", 0.5, "stop", 0,
0, 25, "track1", 360-height/25, 360+height/25, 288-height/25,
288+height/25, 360-height/15, 360+height/15, 288-height/15,
288+height/15, "track2", 2*width/3-height/30, 2*width/3+height/30,
height/3-height/30, height/3+height/30, 2*width/3-height/15,
2*width/3+height/15, height/3-height/15, height/3+height/15,
"track3", 2*width/3-height/30, 2*width/3+height/30, 2*height/3-height/30,
2*height/3+height/30, 2*width/3-height/15, 2*width/3+height/15,
2*height/3-height/15, 2*height/3+height/15, "track4", width/3-height/30,
width/3+height/30, 2*height/3-height/30, 2*height/3+height/30,
width/3-height/15, width/3+height/15, 2*height/3-height/15,
2*height/3+height/15);
Tracker1 = Tracker(TAKE_MOTION_FROM, "1", "1/64", "luminance",
0.75, "use start frame", 0.5, "stop", 1, 1, "v2.0", 0.3,
0.59, 0.11, 0, 10, "track1", width/2, height/2, 1, width/2-height/30,
width/2+height/30, height/2-height/30, height/2+height/30,
width/2-height/15, width/2+height/15, height/2-height/15,
height/2+height/15, width/2, height/2, 1, 1);
QUOTE(rueter @ 04/17/06, 06:03 PM) [snapback]234591[/snapback]
you can simply multiply the expression that points to the track in whatever node you use to pcik up the tracking information.
Something like 'Tracker1.track1X*0.5' for the x value in the Stabilize/Pan/Move2D node will make the track move at 50% speed but also offset the whole thing horizontally so you might have to apply an extra Pan node to shift it back where you need it.
Do the same thing for yPan and you should be set.
There
Fantastic! Thanks very much, This works great!
HOWEVER...
For some wierd reason, using this method, the parallax only shows up when scrubbing through in the Viewer, BUT when I try to make a Flipbook or Disk Flipbook, it renders without the parrallax. What's the deal there? I've flushed all my caches, and the correct node is selected for viewing, so I can't see what's going wrong here. The Console also shows nothing out of the ordinary.
If it matters, I'm applying the multiplier to the applyX params in a Stabilize node. My expression looks like this:
applyX:
track1X*0.5-(track1X@@refFrame*0.5)
applyY:
track1X-(track1X@@refFrame) (I don't need any vertical parallax, obviously, so no multiplier here)
Eww...
Even worse, now when I do a flipbook render, the sky BG gets completely shifted to the entirely wrong position!
argh.
I have a Viewport node in the skyBG tree before it gets piped into the Over node where I comp the house FG with the skyBG. Could this have something to do with it? I'm a fairly new user of Shake, but it seems odd that something can look correct in the Viewer, but look completely incorrect when rendering a Flipbook.
Any further help would rock my proverbial socks.
Hmm this is strange, it looks like I've been bitten by some sort of wierd bug (or is it actually a feature?), as had been previously mentioned in this post.
The culprit seems to be the the Move2D node, which I placed after the Stabilize node in order to reposition the sky plate to match the FG.
When I turn off that Move2D node, what I see in the Viewer is exactly what I (incorrectly) see in the Flipbook render when the Move2d is on!
Is this a bug, or is this supposed to happen? I'm at my wits end here...
the sky wouldnt happen to be a photoshop file, would it?
if so, convert to something less nasty and try again.
++ christoph ++
QUOTE(zem @ 04/18/06, 11:17 AM) [snapback]234708[/snapback]
the sky wouldnt happen to be a photoshop file, would it?
if so, convert to something less nasty and try again.
++ christoph ++
Nope...just a JPG off of Google Images 
not sure i can help, but try posting the entire script here (well, the relevant part) and somebody might jump in.
QUOTE(melorama @ 04/18/06, 09:08 PM) [snapback]234698[/snapback]
If it matters, I'm applying the multiplyer to the applyX params in a Stabilize node. My expression looks like this:
applyX:
track1X*0.5-(track1X@@refFrame*0.5)
If I remember correctly I had a problem like this in the past. Shake wouldn't accept any expressions I put in the "applyX" parameter.
A workaround for this goes like this:
Link your tracks to a second Stabilize node that has the "applyX" left at default. Then add your multiplier (.5) to the track itself and not to the "applyX"
I.e. the "track1X" box should contain something like "Stabilize1.track1X*.5"
That should do... I hope 
FR
P.S.: Here is what I think causes this bug: The Expression found in the "applyX" box (track-track@@refFrame) is replaced with its default string as soon as it renders...
[/quote]
The Expression found in the "applyX" box (track-track@@refFrame) is replaced with its default string as soon as it renders
[quote]
yes that sounds about right, wasn't there some option to "bake" the result in the Stabilize node as opposed to the default "live" or whatever it was called?
I seem to remember that it got implemented for exactly that reason but maybe I'm making things up.
beauty of Shake, he?