Getting Started

nukecontexts is a library of composable context managers for Nuke to manage the state of complex compositing scripts in code.

The most common use case for nukecontexts is automated rendering of multiple states of a compositing script. For example two different output formats, jpg and png.

import nuke
import contextlib
from nukecontexts import ctx

render_node = nuke.toNode('Write1')
with ctx.set_attr(render_node, 'file_type', 'jpeg'):
    nuke.execute(render_node.name(), 1, 1, 1)
with ctx.set_attr(render_node, 'file_type', 'png'):
    nuke.execute(render_node.name(), 1, 1, 1)

The power of nukecontexts comes with composable contexts, using contextlib.nested(). Arbitrarily complex, varying states of the compositing script can be defined and used to automatically generate different results.

merge_node = nuke.toNode('Merge1')
grade_node = nuke.toNode('Grade1')
switch_node = nuke.toNode('Switch1')

ctx1 = ctx.enable([merge_node, grade_node])
ctx2 = ctx.set_attr(grade_node, 'white', 2.0)
ctx3 = ctx.set_attr(switch_node, 'which', 0)
ctx4 = ctx.disable(merge_node)

with contextlib.nested(ctx1, ctx2, ctx3):
    """Render with the merge_node and grade_node enabled, the
    grade_node's white attribute set to 2.0 and the switch_node's switch
    position set to 0."""
    nuke.execute(render_node.name(), 1, 1, 1)

with contextlib.nested(ctx3, ctx4):
    """Render with the switch_node's switch position set to 0 and the
    merge node disabled; the grade_node's gain value remains at the
    original value."""
    nuke.execute(render_node.name(), 1, 1, 1)