change cryptomatte setitings with python

Question

I am trying to turn passes on and off via python. But I can't find out how to change the cryptomatte settings:

this is what the info panel shows when I click on Cryptomatte - Object:

bpy.context.scene.use_pass_crypto_object = True

it returns this:

AttributeError: 'Scene' object has no attribute 'use_pass_crypto_object'

so I tried each of these lines, but none of them work:

bpy.context.scene.view_layers["View Layer"].use_pass_crypto_object = False

bpy.context.scene.render.use_pass_crypto_object = False

bpy.context.scene.use_pass_crypto_object = False

This one doesnt throw an error, but also does nothing, and it is not a UI refresh issue:

bpy.context.scene.cycles.pass_crypto_accurate = False

Does somebody know how to access it? Thanks!

Answer 1

View the UI source

In User Preferences > Interface > Display turn on developer extras. Sounds like you already have. When the path in button hover is dodgy, if available click view source on a field of interest.

In this case it opens addons/cycles/ui.py in text editor at or around the CryptoMatte draw panel where this leaps out

cycles_view_layer = context.view_layer.cycles

Off to the python console:

>>> cycles_view_layer
bpy.data.scenes['Scene']...CyclesRenderLayerSettings

>>> cycles_view_layer.use_pass_crypto_
                                      asset
                                      material
                                      object
>>> cycles_view_layer.use_pass_crypto_object
True

>>> cycles_view_layer.pass_crypto_
                                  accurate
                                  depth
>>> cycles_view_layer.pass_crypto_depth
6

>>> cycles_view_layer.pass_crypto_depth = 10
>>> 

can put in accurate mode with

cycles_view_layer.pass_crypto_accurate = True

Some more fiddling, the property is displayed as belonging to scene

>>> cycles_view_layer.id_data
bpy.data.scenes['Scene']

>>> C.scene.view_layers['RenderLayer'].cycles
bpy.data.scenes['Scene']...CyclesRenderLayerSettings

>>> cycles_view_layer
bpy.data.scenes['Scene']...CyclesRenderLayerSettings

>>> C.scene.view_layers['RenderLayer'].cycles is cycles_view_layer
False

>>> C.scene.view_layers['RenderLayer'].cycles == cycles_view_layer
True

Answer 2

solution from batFinger:

from bpy import context
cycles_view_layer = context.view_layer.cycles
cycles_view_layer.use_pass_crypto_object=False

thanks!