(Another) Zelda Ripping Project!

[JamesO2]

About vertex color formula vertexColor * 2 * baseColor:

That's also the formula the PS1 used (it let's you also brighten textures instead of only darkening them). The neutral point where there's no effect on the texture is vertexColor=0.5 since 2*0.5=1. But if it's like the PS1 it's supposed to be in sRGB space. Starting in Blender 2.8, colors are passed around in linear space, so 0.5 (sRGB) will be passed into the node as 0.22 (linear) and 2*0.22=0.44 which makes things too dark. So you can try using a factor of about 4.6 instead of 2 to keep the neutral point neutral. I found this worked pretty well for PS1 models I tried. Unfortunately it loses accuracy as you move away from vertexColor=0.5, but maybe you can try it and see if it's any better than changing the global exposure.

Oh cool, that's good to know. I did some earlier experimentation with Vertex Coloring and noticed the same thing you mentioned: that the mid colors (0.5) seemed neutral, while the darks were darker and the lights were lighter. But I couldn't get it to look quite right in Blender 2.9 at the time because I wasn't familiar enough with the program.

I did read from somewhere that Blender made a change into using "linear space" for color and lighting calculations, which I guess is generally better for realistic 3D work, or "how humans would interpret colors" more so. But in this particular case we aren't trying to recreate a realistic 3D space, but a very specific sRGB color space, so yeah that does cause some issue.

I wasn't aware of the exact math behind linear/sRGB calculations, but I was able to correct the 0.44 color imbalance by adjusting the scene's Color Exposure to 1.2. Which, if my math is correct, may have pushed that 0.44 into being perceptually closer to 0.528, which would make it look closer to correct. Adjusting the scene exposure does work, but it also has the effect of over-brightening any object that isn't using this specific shader too.

I'll experiment with the numbers you mentioned here later though and see what I can get. You seem much more knowledgeable about the exact math of it all -- I just approach the issue from an artist perspective, so I'm eyeballing it to get colors at approximate correct values.

I don't know much python, but I skimmed over that link you posted. Is that an entire automation script to import Vagrant Story models? It looks like it even automates the "File > Import" process too, if I'm correct. I'll have to look at it closer.

Do you have a sample model I can borrow to test out your script (or point me to a link to which models you used)?

Here's an interesting thought: I know that you can change the rendering engine in a Blend file, the usual options being "Eevee, Workbench, or Cycles". And I know there used to be an older Blender Render which was scrapped to focus on improving Eevee. Would it be possible to write a 4th render engine that is specialized to render in a videogame sRGB manner? I wouldn't expect it written from scratch, more so a tweaked Eevee renderer that just adjusts some of the internal math values to be more in line with sRGB color space.