reset vfb exposure to 0 via python script

[mschreck]

Hi,

Is there a way to reset the exposure in the VFB via script. I got a couple of situations where i didn´t notice/forgot to reset it. It would be nice to revert this in a new session.
Or is there a vray preference setting for that?

Maya 2022.3 + vray 5.1

[hermit.crab]

Which exposure are we talking about? An exposure layer or in the display correction?

[mschreck]

nevermind-i was referring to the layer
The problem is that i sometimes dont realize i changed the exposure at some point and then when i reopen the scene i would expect it to be reset but it isnt.

chat gpt for the win:

import maya.mel as mel

# Step 1: Retrieve the display correction layer ID
disp_corr_layer_id = mel.eval('vray vfbControl -displayCorrectionLayer;')
print("Display Correction Layer ID:", disp_corr_layer_id)

# Step 2: Get the current exposure value
current_exposure = mel.eval('vray vfbControl -layer {} -get "exposure";'.format(disp_corr_layer_id))
print("Current Exposure:", current_exposure)

# Step 3: Set the exposure value to 0.0
mel.eval('vray vfbControl -layer {} -set "exposure" 0.0;'.format(disp_corr_layer_id))

# Step 4: Verify the exposure value was updated
new_exposure = mel.eval('vray vfbControl -layer {} -get "exposure";'.format(disp_corr_layer_id))
print("New Exposure:", new_exposure)

[hermit.crab]

To reset the Display correction Exposure (display only) for Python:

import maya.cmds as cmds

cmds.vray('vfbControl', '-layer', 1, '-set', "exposure", 0)​

To reset the Exposure value of an Exposure layer, you need to find out the ID of the layer (via -listLayers and -layer <id> -name) and run this:

import maya.cmds as cmds

cmds.vray('vfbControl', '-layer', 9, '-set', "exposure", 1)​

More info on controlling the VFB programmatically here.

t would be nice to revert this in a new session.Or is there a vray preference setting for that?

Are you using a preset?

EDIT: Didn't refresh the page. Let me read your last post.
ChatGPT has a tendency to invent its own argument and property names that are not nonexistent. I doubt the code will work, but try it out.

EDIT 2: Surprisingly, it works.

[mschreck]

haha, yes. ChatGPT is very creative in making up its own code if it runs into problems.
we use a render startup script that takes care of a couple of maya and vray color and light settings etc.
I now implemented this into the script and that way i make sure the session is always exactly the same.