PNG with metallic and smoothness - How can I edit (in PS) the two separately within one PNG?

Bumper · Apr 2018

Hey all - so I'm stumped. I'm relatively new to Unity and am having difficulty getting used to using a PNG (format is client mandated) for metallic/smoothness. My PNGs are coming out of Painter which has combined my metal/smooth upon export.

I understand that the value AND transparency work together to affect metal/smooth. What I want to know is how I could go about editing/tweaking the two separately. I would MUCH prefer to use TGAs, where I could more readily access the color channels and alpha for editing independantly.

Any help would be much appreciated!

Obscura · Apr 2018

I doubt that the transparency "works together" with those. I believe it works the same as tga, and the transparency should do nothing, unless its grabbed by some another property of the shader. But even then it does't affect the metallic - smoothness maps. Feel free to correct me if I'm wrong, I'm mainly not a Unity user, but I used it in the past several times.

Axi5 · Apr 2018

Hi Bumper

In Photoshop, if you open your PNG and then go to:

Layer -> Layer Mask -> From Transparency

It'll create an alpha channel on your PNG for you to play with.

Bumper · Apr 2018

Obscura said:

I doubt that the transparency "works together" with those. I believe it works the same as tga, and the transparency should do nothing, unless its grabbed by some another property of the shader. But even then it does't affect the metallic - smoothness maps. Feel free to correct me if I'm wrong, I'm mainly not a Unity user, but I used it in the past several times.

Unless I'm mistaken, the Unity Standard shader looks at the transparency (alpha) as a measure of smoothness, and the RGB values for metal.

Bumper · Apr 2018

Axi5 said:

Hi Bumper

In Photoshop, if you open your PNG and then go to:
Layer -> Layer Mask -> From Transparency

It'll create an alpha channel on your PNG for you to play with.

Thank you! That is magic. I really appreciate the help.

poopipe · Apr 2018

Remember to stop photoshop converting colour spaces and wrecking your data.

Or as I usually advise when working with substance - stay away from photoshop

Obscura · Apr 2018

Right. Now I dug a little bit in it on the internet as currently I don't have Unity installed, and it turns out that you can store the smoothness only in alpha channel of some map. But you can select which map to grab from (smoothness source). This is kinda weird though because having an alpha channel, when you could pack metallic, smoothness, and ao together for example, is a waste. Oh well.

Noors · Apr 2018

Yes smoothness on alpha and metallic on red.
It's a bit silly use of textures, but well you can still make your own (surface) shader if needed.

As for png, i never really got this format, or is it photoshop ? If it's pure transparent, how can you specify the color ? Seems to be a poor choice for packing single channel textures.

kio · Apr 2018

its photoshop which handles PNG alpha in a .. not so cool manner. I dont get why its alpha is treated differently than in other formats, but oh well..

This should help you:
http://www.fnordware.com/superpng/

Farfarer · Apr 2018

Yeah, use SuperPNG, which will let you treat the alpha channel as, well, an alpha channel - rather than transparency.

Photoshop's native handling of PNG sucks.

Bumper · Apr 2018

kio said:

its photoshop which handles PNG alpha in a .. not so cool manner. I dont get why its alpha is treated differently than in other formats, but oh well..

This should help you:
http://www.fnordware.com/superpng/

Gah, that is awesome! I really should come out from under my rock more often. Thank you so much.

PNG with metallic and smoothness - How can I edit (in PS) the two separately within one PNG?

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