Option to remove emission from prep materials

[StandingPadAnimations]

Changed the branch so reopening

Work on this feature began in Kaion, and now I'm just refining this feature.

This adds an option to prep materials to not add emissive nodes, which can help to reduce noise in Cycles and makes nodes less complex in EEVEE.

[TheDuckCow]

Did not live test, just code review. I see your other branches continue to reference needing to merge this first, let me know when you're ready for me to do a further review - but did a first pass just now.

Hence, just responding with "comment" for now instead of approve. Overall the change looks good, just needs a live test from me!

[StandingPadAnimations]

I've fixed some bugs that were caused because until now I didn't have an easy way to test

The difference is profound

[StandingPadAnimations]

Looks like prepping on more complex OBJs returns the following error:

Python: Traceback (most recent call last):
  File "C:\Users\Mahid\AppData\Roaming\Bforartists\Bforartists\3.5\scripts\addons\MCprep_addon\tracking.py", line 806, in wrapper
    res = function(self, context)
  File "C:\Users\Mahid\AppData\Roaming\Bforartists\Bforartists\3.5\scripts\addons\MCprep_addon\materials\prep.py", line 252, in execute
    res = generate.matprep_cycles(
  File "C:\Users\Mahid\AppData\Roaming\Bforartists\Bforartists\3.5\scripts\addons\MCprep_addon\materials\generate.py", line 391, in matprep_cycles
    res = matgen_cycles_principled(
  File "C:\Users\Mahid\AppData\Roaming\Bforartists\Bforartists\3.5\scripts\addons\MCprep_addon\materials\generate.py", line 1578, in matgen_cycles_principled
    texgen_seus(mat, passes, nodeInputs, use_reflections)
  File "C:\Users\Mahid\AppData\Roaming\Bforartists\Bforartists\3.5\scripts\addons\MCprep_addon\materials\generate.py", line 1279, in texgen_seus
    links.new(nodeSaturateMix.outputs[saturateMixOut[0]], i)
RuntimeError: Error: Same input/output direction of sockets

[StandingPadAnimations]

Ok that was an easy fix, but I've also noticed that the following occurs:

It seems like for some reason MCprep is now putting the B output of Separate RGB to the normal input

I think we need to check if inputs are valid

[StandingPadAnimations]

Ight I was able to fix it with the following:

if use_emission:
    for i in nodeInputs[2]:
        links.new(nodeSeperate.outputs["B"], i)

[TheDuckCow]

FYI I just using the test runner on this branch, getting some errors, can you take a quick look?

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/patrickcrawford/Library/Application Support/Blender/3.2/scripts/addons/MCprep_addon/tracking.py", line 856, in wrapper
    bpy.ops.mcprep.report_error('INVOKE_DEFAULT', error_report=err)
  File "/Applications/blender 3.2/Blender.app/Contents/Resources/3.2/scripts/modules/bpy/ops.py", line 113, in __call__
    ret = _op_call(self.idname_py(), C_dict, kw, C_exec, C_undo)
RuntimeError: Error: Python: Traceback (most recent call last):
  File "/Users/patrickcrawford/Library/Application Support/Blender/3.2/scripts/addons/MCprep_addon/tracking.py", line 827, in wrapper
    res = function(self, context)
  File "/Users/patrickcrawford/Library/Application Support/Blender/3.2/scripts/addons/MCprep_addon/materials/prep.py", line 566, in execute
    res, err = self.update_material(context, mat)
  File "/Users/patrickcrawford/Library/Application Support/Blender/3.2/scripts/addons/MCprep_addon/materials/prep.py", line 633, in update_material
    res = generate.matprep_cycles(
TypeError: matprep_cycles() missing 1 required positional argument: 'use_emission_nodes'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/Users/patrickcrawford/Library/Application Support/Blender/3.2/scripts/addons/MCprep_addon/tracking.py", line 617, in execute
    raise Exception(self.error_report)
Exception:   File "<addon_path>/prep.py", line 566, in execute
    res, err = self.update_material(context, mat)
  File "<addon_path>/prep.py", line 633, in update_material
    res = generate.matprep_cycles(
TypeError: matprep_cycles() missing 1 required positional argument: 'use_emission_nodes'
Location: /Applications/blender 3.2/Blender.app/Contents/Resources/3.2/scripts/modules/bpy/ops.py:113

	TEST FAILED:
	Did not end with finished result

[TheDuckCow]

I'm going to push a single change and then this is good to go. See comment below of one thing I've changed, to not disable emission in Eevee.

I'm going to merge it now.

[TheDuckCow]

I would argue against this, as having emission means it at least appears brighter even if it doesn't actually give off light. Plus, people can technically use light probes. What harm is there in having emission on in Eevee? I also find that I often switch from eevee to cycles when I first get to rendering as I wasn't thinking about it right away.