[Camera Smooth] Create a copy of the selected camera node, using a weighted average of surrounding frames #nuke

cameraSmooth.py

"""
Smooth Camera
Creates a new camera linked to the selected one, with a weighted average of the position/rotation curves.
"""
import nuke


def deselectAll():
    for node in nuke.selectedNodes():
        node.setSelected(False)

def createSmoothCopy(cam):
    """
    Create a copy cam
    @type cam: nuke.Node
    @return:
    """
    answ = nuke.getInput("how many frames to smooth by", "3")
    frameDist = int(answ)

    deselectAll()
    cam.setSelected(True)

    nuke.nodeCopy("%clipboard")
    cam.setSelected(False)

    nuke.nodePaste("%clipboard%")
    newCam = nuke.selectedNode()

    for knobName in ("translate", "rotate"):
        knob = newCam[knobName]
        for channel, channelName in enumerate("xyz"):
            knob.clearAnimated(channel)

            w_sum = 1
            numerator = "{}.{}.{}(frame)".format(cam.fullName(), knobName, channelName)
            for i in range(frameDist):
                w = 1.0 / (i+2)
                numerator += " + {:0.2f}*{}.{}.{}(frame+{})".format(w, cam.fullName(), knobName, channelName, i+1)
                numerator += " + {:0.2f}*{}.{}.{}(frame-{})".format(w, cam.fullName(), knobName, channelName, i+1)
                w_sum += 2*w

            expr = "({}) / {}".format(numerator, w_sum)
            knob.setExpression(expr, channel)

    return newCam


if __name__ == '__main__':
    createSmoothCopy(nuke.selectedNode())