Slice and plot scanlines in Nuke!

I’ve been playing with the expression node in Nuke lately, and one of the things I made was  a simple Slice tool/scanline plotter. It can sample a slice (between two points) and will plot the color values as a curve over the image.

I’ve wrapped it up in a group with a set of exposed parameters, but not exported as a gizmo, just because it might be handy to just copy/pasta it into your scripts somewhere  without the need to embed it into a pipeline.

It has three modes, per pixel which is checking the raw pixels, and a sample area which is similar to the per pixel method but it can sample a larger area pr pixel as well. (using the ex:  r(x,y,5,5) function) and one that will use the first point to determine which full scanline to sample and plot.

Maybe someone will find it usefull, maybe someone will……….buy me a beer….


set cut_paste_input [stack 0]
version 6.1 v1
push $cut_paste_input
Group {
name PlotScanline
selected true
xpos -839
ypos 206
addUserKnob {20 Controls}
addUserKnob {4 mode l "Sampling method" M {"Slice Per Pixel (faster)" "Slice Area (slower)" "Full Scanline" "" "" ""}}
mode "Full Scanline"
addUserKnob {6 add2image l "Add to original" +STARTLINE}
add2image true
addUserKnob {6 Normalize -STARTLINE}
addUserKnob {6 tonemap l "Tone Map (HDRI)" -STARTLINE}
addUserKnob {6 curve l "Plot as curve" +STARTLINE}
curve true
addUserKnob {3 curveFat l "Curve Thickness" -STARTLINE}
addUserKnob {3 sa l "Sample Area" t "Disabled when using pr pixel method."}
sa 1
addUserKnob {7 lift l Lift R -1 1}
addUserKnob {7 scale l Scale R 0 5}
scale 1
addUserKnob {26 ""}
addUserKnob {12 p1 l "Start Point"}
p1 {376 418}
addUserKnob {12 p2 l "End Point" -STARTLINE}
p2 {428.5 425.5}
addUserKnob {26 ""}
addUserKnob {26 "" l "About " T "Plot Scanline v0.4 | theo@euqahuba.com\nUse P1 to select your scanline and/or you start slice."}
}
Input {
inputs 0
name Input1
xpos -480
ypos 62
}
set N3069610 [stack 0]
Expression {
temp_name0 length
temp_expr0 sqrt(r*r+g*g+b*b)
expr0 r/length
expr1 g/length
expr2 b/length
name Normalize
xpos -480
ypos 108
disable {{1-parent.Normalize i}}
}
Expression {
expr0 r/(r+1)
expr1 g/(g+1)
expr2 b/(b+1)
name tonamap
xpos -480
ypos 134
disable {{1-parent.tonemap i}}
}
set N7fe58a0 [stack 0]
Expression {
temp_name0 rExpr
temp_expr0 "min(max(0,\r\nceil(r(x,parent.p1.y)-((y/height+parent.lift)*parent.scale))),1)"
temp_name1 gExpr
temp_expr1 "min(max(0,\r\nceil(g(x,parent.p1.y)-((y/height+parent.lift)*parent.scale))),1)"
temp_name2 bExpr
temp_expr2 "min(max(0,\r\nceil(b(x,parent.p1.y)-((y/height+parent.lift)*parent.scale))),1)"
expr0 rExpr
expr1 gExpr
expr2 bExpr
expr3 0
name scanline
xpos -302
ypos 193
addUserKnob {20 User}
}
push $N7fe58a0
Expression {
temp_name0 rExpr
temp_expr0 "min(max(0,\r\nceil(r((x/width)*(parent.p2.x-parent.p1.x)+parent.p1.x,(x/width)*(parent.p2.y-parent.p1.y)+parent.p1.y,parent.sa,parent.sa)-((y/height+parent.lift)*parent.scale))),1)"
temp_name1 gExpr
temp_expr1 "min(max(0,\r\nceil(g((x/width)*(parent.p2.x-parent.p1.x)+parent.p1.x,(x/width)*(parent.p2.y-parent.p1.y)+parent.p1.y,parent.sa,parent.sa)-((y/height+parent.lift)*parent.scale))),1)"
temp_name2 bExpr
temp_expr2 "min(max(0,\r\nceil(b((x/width)*(parent.p2.x-parent.p1.x)+parent.p1.x,(x/width)*(parent.p2.y-parent.p1.y)+parent.p1.y,parent.sa,parent.sa)-((y/height+parent.lift)*parent.scale))),1)"
expr0 rExpr
expr1 gExpr
expr2 bExpr
expr3 0
name Expression_highQuality
xpos -515
ypos 197
addUserKnob {20 User}
}
push $N7fe58a0
Expression {
temp_name0 rExpr
temp_expr0 "min(max(0,\r\nceil(r((x/width)*(parent.p2.x-parent.p1.x)+parent.p1.x,(x/width)*(parent.p2.y-parent.p1.y)+parent.p1.y)-((y/height+parent.lift)*parent.scale))),1)"
temp_name1 gExpr
temp_expr1 "min(max(0,\r\nceil(g((x/width)*(parent.p2.x-parent.p1.x)+parent.p1.x,(x/width)*(parent.p2.y-parent.p1.y)+parent.p1.y)-((y/height+parent.lift)*parent.scale))),1)"
temp_name2 bExpr
temp_expr2 "min(max(0,\r\nceil(b((x/width)*(parent.p2.x-parent.p1.x)+parent.p1.x,(x/width)*(parent.p2.y-parent.p1.y)+parent.p1.y)-((y/height+parent.lift)*parent.scale))),1)"
expr0 rExpr
expr1 gExpr
expr2 bExpr
expr3 0
name perPixel
xpos -419
ypos 201
addUserKnob {20 User}
}
Switch {
inputs 3
which {{parent.mode i}}
name Switch2
xpos -480
ypos 253
}
Matrix {
matrix {
{0 1 0}
{1 -4 1}
{0 1 0}
}
name Matrix2
selected true
xpos -480
ypos 284
disable {{-1+parent.curve i x70 1}}
}
Dilate {
size {{parent.curveFat}}
name Dilate1
xpos -480
ypos 326
disable {{-1+parent.curve.main}}
}
Clamp {
name Clamp1
xpos -480
ypos 383
}
set N86e9e00 [stack 0]
push $N3069610
Dot {
name Dot1
xpos -556
ypos 66
}
Clamp {
maximum 331
name Clamp2
xpos -590
ypos 352
}
Merge2 {
inputs 2
operation plus
bbox intersection
name Merge1
xpos -590
ypos 394
}
Dot {
name Dot2
xpos -556
ypos 433
}
push $N86e9e00
Switch {
inputs 2
which {{parent.add2image i}}
name Switch1
xpos -480
ypos 425
}
Output {
name Output1
xpos -480
ypos 470
}
end_group