Heh, I remember trying the exact same thing in Shake years ago, to
transform a roto point instead of using a 4-point stablise - the problem
is the dod was an integer
Nuke's appears to be not be an integer, but the values in your tree
appear to either be 0.0 or 0.5, which is slightly odd
Seems like it'd be fairly simple to make a plugin which exposes the 2D
transform matrix,
http://docs.thefoundry.co.uk/nuke/63/ndkdevguide/knobs-and-handles/output-knobs.html
Ivan Busquets wrote:
it looks like nuke gives a rounding error using that setup (far
values are .99902 instead of 1.0). probably negligible but I like
1.0 betta.
One small thing about both those UV-map generation methods. Keep in mind
that STMap samples pixels at the center, so you'll need to account for
that half-pixel difference in your expression. Otherwise the resulting
map is going to introduce a bit of unnecessary filtering when you feed
it to an STmap.
An expression like this should give you a 1-to-1 result when you feed it
into an STMap:
----------------------------------------------------
set cut_paste_input [stack 0]
version 6.3 v2
push $cut_paste_input
Expression {
expr0 (x+0.5)/(width)
expr1 (y+0.5)/(height)
name Expression2
selected true
xpos -92
ypos -143
}
----------------------------------------------------
With regards to the original question, though, it's a shame that one
doesn't have access to the concatenated 2d matrix from 2D transform
nodes within expressions. Otherwise you could just multiply your source
point by the concatenated matrix and get its final position. This
information is indeed passed down the tree, but it's not accessible for
anything but plugins (that I know).
You could probably take advantage of the fact that the bbox is
transformed the same way as your image, and you CAN ask for the bbox
boundaries using expressions. So, you could have something with a very
small bbox centered around your point of interest, transform that using
the same transforms you're using for your kites, and then get the center
of the transformed bbox, if that makes sense. It's a bit convoluted, but
it might do the trick for you.
Here's an example:
----------------------------------------------------
set cut_paste_input [stack 0]
version 6.3 v2
push $cut_paste_input
Group {
name INPUT_POSITION
selected true
xpos -883
ypos -588
addUserKnob {20 User}
addUserKnob {12 position}
position {1053.5 592}
}
Input {
inputs 0
name Input1
xpos -469
ypos -265
}
Rectangle {
area {{parent.position.x i x1 962} {parent.position.y i x1 391}
{area.x+1 i} {area.y+1 i}}
name Rectangle1
selected true
xpos -469
ypos -223
}
Output {
name Output1
xpos -469
ypos -125
}
end_group
Transform {
translate {36 0}
center {1052 592}
shutteroffset centred
name Transform1
selected true
xpos -883
ypos -523
}
set C48d17580 [stack 0]
Transform {
translate {0 -11}
rotate -34
center {1052 592}
shutteroffset centred
name Transform2
selected true
xpos -883
ypos -497
}
set C4489ddc0 [stack 0]
Transform {
scale 1.36
center {1052 592}
shutteroffset centred
name Transform3
selected true
xpos -883
ypos -471
}
set C4d2c2290 [stack 0]
Group {
name OUT_POSITION
selected true
xpos -883
ypos -409
addUserKnob {20 User}
addUserKnob {12 out_position}
out_position {{"(input.bbox.x + input.bbox.r) / 2"} {"(input.bbox.y +
input.bbox.t) / 2"}}
}
Input {
inputs 0
name Input1
selected true
xpos -469
ypos -265
}
Output {
name Output1
xpos -469
ypos -125
}
end_group
CheckerBoard2 {
inputs 0
name CheckerBoard2
selected true
xpos -563
ypos -623
}
clone $C48d17580 {
xpos -563
ypos -521
selected true
}
clone $C4489ddc0 {
xpos -563
ypos -495
selected true
}
clone $C4d2c2290 {
xpos -563
ypos -469
selected true
}
----------------------------------------------------
Cheers,
Ivan
On Tue, Sep 6, 2011 at 6:09 PM, J Bills <jbillsn...@flickfx.com
<mailto:jbillsn...@flickfx.com>> wrote:
sure - looks even cleaner than the ramps crap done from memory -
actually, now that I look at it for some reason it looks like nuke
gives a rounding error using that setup (far values are .99902
instead of 1.0). probably negligible but I like 1.0 betta. nice
one AK.
so play around with this, joshua -
set cut_paste_input [stack 0]
version 6.2 v4
Constant {
inputs 0
channels rgb
name Constant2
selected true
xpos 184
ypos -174
}
Expression {
expr0 x/(width-1)
expr1 y/(height-1)
name Expression2
selected true
xpos 184
ypos -71
}
NoOp {
name WARP_GOES_HERE
tile_color 0xff00ff
selected true
xpos 184
ypos 11
}
Shuffle {
out motion
name Shuffle
label "choose motion\nor other output\nchannel"
selected true
xpos 184
ypos 83
}
push 0
STMap {
inputs 2
channels motion
name STMap1
selected true
xpos 307
ypos 209
}
On Tue, Sep 6, 2011 at 5:23 PM, Anthony Kramer
<anthony.kra...@gmail.com <mailto:anthony.kra...@gmail.com>> wrote:
Heres a 1-node UVmap for you:
set cut_paste_input [stack 0]
version 6.3 v2
push $cut_paste_input
Expression {
expr0 x/(width-1)
expr1 y/(height-1)
name Expression2
selected true
xpos -480
ypos 2079
}
On Tue, Sep 6, 2011 at 4:46 PM, J Bills <jbillsn...@flickfx.com
<mailto:jbillsn...@flickfx.com>> wrote:
sure - that's what he's saying. think of the uv map as
creating a "blueprint" of your transforms or distortions.
after you have that blueprint, you can run whatever you want
through the same distortion and repurpose it all day long
for whatever you want that might need it. so if you need it
for some utility use to know where pixel 1234x735 is, just
UV map those distortions and then put a little paint dot at
1234x735 and run it through the stmap using that uvmap.
1234x735 will be magically whisked away to 1414x644 or
wherever your transforms take it.
here's an example for you to plug your xforms into, and then
your paint blob or whatever would go into the stmap:
set cut_paste_input [stack 0]
version 6.3 v2
Constant {
inputs 0
channels rgb
name Constant2
selected true
xpos 2862
ypos 1292
}
set Ncc0e6650 [stack 0]
Ramp {
output {rgba.red -rgba.green -rgba.blue -rgba.alpha}
p0 {{width-width} 100}
p1 {{width} 100}
name Ramp3
selected true
xpos 2970
ypos 1387
}
push $Ncc0e6650
Ramp {
output {-rgba.red rgba.green -rgba.blue -rgba.alpha}
p0 {100 {height-height}}
p1 {100 {height}}
name Ramp4
selected true
xpos 2862
ypos 1384
}
Copy {
inputs 2
from0 rgba.red
to0 rgba.red
name Copy3
selected true
xpos 2862
ypos 1449
}
NoOp {
name WARP_GOES_HERE
tile_color 0xff00ff
selected true
xpos 2862
ypos 1519
}
Shuffle {
out motion
name Shuffle
label "choose output\nchannel"
selected true
xpos 2862
ypos 1565
}
push 0
STMap {
inputs 2
uv motion
name STMap1
selected true
xpos 2985
ypos 1675
}
On Tue, Sep 6, 2011 at 3:59 PM, Joshua LaCross
<nuke-users-re...@thefoundry.co.uk
<mailto:nuke-users-re...@thefoundry.co.uk>> wrote:
__
Thanks Anothony. The kites are already in the scene. I'm
trying get the positional x and y values after going
through all the additional transforms
_______________________________________________
Nuke-users mailing list
Nuke-users@support.thefoundry.co.uk
<mailto:Nuke-users@support.thefoundry.co.uk>,
http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
_______________________________________________
Nuke-users mailing list
Nuke-users@support.thefoundry.co.uk
<mailto:Nuke-users@support.thefoundry.co.uk>,
http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
_______________________________________________
Nuke-users mailing list
Nuke-users@support.thefoundry.co.uk
<mailto:Nuke-users@support.thefoundry.co.uk>,
http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
_______________________________________________
Nuke-users mailing list
Nuke-users@support.thefoundry.co.uk
<mailto:Nuke-users@support.thefoundry.co.uk>,
http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
------------------------------------------------------------------------
_______________________________________________
Nuke-users mailing list
Nuke-users@support.thefoundry.co.uk, http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
--
ben dickson
2D TD | ben.dick...@rsp.com.au
rising sun pictures | www.rsp.com.au
_______________________________________________
Nuke-users mailing list
Nuke-users@support.thefoundry.co.uk, http://forums.thefoundry.co.uk/
http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
