Nuke show-node-with-postage-stamps nonsense

gistfile1.py

"""Nuke/Python script that displays the selected node in the DAG
using a lot of node postage-stamps.. Not *exactly* useful..

http://img46.imageshack.us/img46/923/nukenodalimgviewer.png
"""

import nuke

def getRGB(node, x, y):
    return [node.sample(chan, x, y) for chan in ['red', 'green', 'blue']]

def getColourBlocks(sourcenode, xnumblocks, ynumblocks):
    w = sourcenode.width()
    h = sourcenode.height()

    perWidthStep = w / xnumblocks
    perHeightStep = h / ynumblocks

    lines = {}
    for x in range(xnumblocks):
        for y in range(ynumblocks):
            curx, cury = perWidthStep * x, perHeightStep * y
            cury = h - cury
            lines[(x, y)] = getRGB(sourcenode, curx, cury)
    return lines

def genNode(x, y):
    nn = nuke.nodes.Constant()
    nn['label'].setValue("%dx%d" % (x, y))
    nn.setXYpos(x, y)
    return nn

def genGrid(numx, numy, spacex, spacey):
    lines = {}
    for x in range(numx):
        for y in range(numy):
            curx, cury = x * spacex, y * spacey
            n = genNode(curx, cury)
            lines[(x, y)] = n
    return lines

def paintGrid(sourceimg, lines):
    for k, v in sourceimg.items():
        x, y = k
        lines[(x, y)]['color'].setValue(v + [1])

def removeAllConstants():
    for x in nuke.allNodes():
        if x.Class() == "Constant":
            nuke.delete(x)

def selectedToPostagestamps():
    # removeAllConstants()
    sourceimg = nuke.selectedNode()
    sourceimg.setXYpos(-200, -200)

    colours = getColourBlocks(sourceimg, 50, 25)
    grid = genGrid(50, 25, 100, 100)
    paintGrid(colours, grid)

nuke.menu("Nodes").addCommand("Other/Selected to Postage-stamp-viewer", "selectedToPostagestamps()")