White fringing around Alpha'd Bitmap in Composite Maps, help?

[HowardDay]

Howdy, guys. So I'm running into something I have been unable to fix. I've got a composity map with a bitmap in a triplanar map. This bitmap has an alpha component to it, and I'm getting some white fringing. There's no white on this map - it's a TGA with a dark gray color channel and detail in the alpha. I've tried TGA, PSD, and PNG - none can resolve this. I've tried Premultiplied both on and off. I cannot Changing the Bitmap to a VRayHDRI also doesnt solve this issue. So far, the best I can seem to fix this is by using a second copy of the map in the composite layer alpha slot, using color correction to set all the channels to "alpha". This doesnt actually get rid of the problem, just trims away a bit of the white.

I hope there's an easy way to fix this that I've overlooked.
Thanks!

[^Lele^]

I tried doing the same thing, and have no issue.
Can you share the shader setup which creates this?

[HowardDay]

Sure! Here's the scene, with the model part in question: https://drive.google.com/file/d/1WCG...ew?usp=sharing
And here's part of the render that results:
I am using the RTX render engine, Dunno if that matters.

Thanks!

[^Lele^]

It's the Bitmap gamma being wrong, by virtue of the max gamma setup being off.
If you turn the max LUT/gamma on at defaults, the issue will disappear.

Alternatively, set the bitmap gamma from sRGB to none, or manual 1.0.

[HowardDay]

I've tried both those things, with no joy on my end. I've reduced it to the simpliest possible scene - a ball blending between two textures. If you can give this another look, and fix it, I'd appreciate you sending it back, cause as of now, no combination of things is fixing the issue.
Here's the file:https://drive.google.com/file/d/1xLy...ew?usp=sharing
And here's the result. you can plainly see white fringing still apparent, even with Max's Gamma setup turned on defaults.

[^Lele^]

Umh, indeed it had looked fine (ish. the alpha would show dots) on dark colors.
I have not managed to fix it with that bitmap (changed composite map and render engine too.), however, i saved myself an alphaed tga from photoshop, and this is what i got putting it in place of yours.

[HowardDay]

Extremely odd. Thanks for taking a look at it! I made the image in photoshop, too, and I have no idea why it would be having issues like this.

[^Lele^]

All i can think of is that somehow the alpha premult is done against the wrong RGB color space.
However you managed to save the image so. Maybe CMYK working space, which then PS gets wrong when transforming to RGB?

[HowardDay]

Ah! Nothing quite so simple. I think I figured it out. under Color settings, I turned *On* the blend layers by gamma option at 1.0. The only reason I even thought to look here was that I dimly remembered turning this on a while ago, and thought that perhaps turning it off would fix the issue. One restart later, I simply opened the TGA, and re-saved it...and everything works. What the crap. Thanks so much for your help, Lele!

[^Lele^]

Yw! Splendid that you found out!