Metallic alpha channel being ignored when exporting textures for unity 5

RabidRabit

He dudes and dudettes. Posted this over in the Allegorithmic forums as well. This one of the most random problems i've ever encountered:



I am trying to export for Unity 5. 

When I imported my asset into the engine I noticed it was looking super wet and greasy which was not the intention. I checked the texture in photoshop and noticed that the Metal map isn't being packed with the smoothness/roughness. My first instinct was to delete allegorithmic folder from the shelf to restore all the export settings yet the issue still persists.

Any idea's on what is going on here?

Thanks in advance!

Son Kim

I ran into a similar problem not so long ago, if you save your textures as PNG, it will not save the alpha channel. Try another file format like TARGA. You can also download a free plugin call Super PNG, which add alpha channel support.

RabidRabit

Ah, I've used super png within photoshop to export maps before. Didn't realize that would also plug into painter. The weird part is every other asset I have made in painter has exported fine. Has me wondering what I have done differently this time around.

RabidRabit

Your post inspired me to do a weird workaround. Exported the maps as TGA's from painter with the Alpha intact then re-exported from photoshop with the superpng plugin. Still wondering what the issue with painter is but at least I am able to get the textures into unity. Thanks Son Kim!

Son Kim

You could just stick to TGA, I think Unity support TGA last time I check. It would be annoying to have to use that workaround when you have tons of asset to do.

RabidRabit

Very true, I am hoping the problem just goes away haha. I would also have to consider switching every other asset in the project from PNG to TGA haha. More trouble than its worth for a glitch I think

Froyok

There is no issue. The PNG file format support only transparency, not an alpha channel (contrary to the TGA file format). In Photoshop you can extract the transparency as a mask by doing Layer > Layer Mask > From Transparency.

As for why your exported texture would be fully transparent, it's probably because you painted on the mesh but not with an opacity of 100%. Therefor the exported texture contains your paint blended with a black color and with the alpha mask stored as transparency. Putting a fill layer at the bottom of the layer stack is a good way to get rid of that.

RabidRabit

Thanks Froyok!

That is probably the difference between this asset and the others I have created. I'll check some of my previous files to confirm

Cheers