Help fixing Alpha channel

[TREBoy]

Hey, first time poster here!

 

I've used Paint.NET for as long as I can remember, and love every aspect of it. Recently, I've been dipping my toes in color channels, and I must say, they're a bit confusing to me. I'm currently working on eyebrow textures for a game that uses .DDS format, and found a problem with the textures I made related to the Alpha channel. 

 

My process was: opening ClipStudio, deleting all layers non transparent, making the texture, saving as PNG, moving to Paint.NET, finishing the texture up, saving as DDS. But apparently there's an issue in the process in ClipStudio that made it so all my textures have a "fake" transparent background, so even though it looks transparent in any image viewer, when you invert the Alpha channel, the background turns white instead of black.

 

Actually deleting a chunk of the background with the select tool in Paint.NET seems to fix this issue for that chunk, but the texture isn't set up in a way that would make the background easy to remove (the texture isn't flat, meaning it has different transparencies along the way).

 

I found some sort of a fix, by simply creating another transparent layer and merging the both. Doing that seems to fix the alpha channel somehow, but another issue appears:

The image shows the texture with it's alpha channel inverted. It is black, as intended, but there are a few white squares here and there that don't seem quite right. 

 

So after a lot of trial and error, I'm here asking for some insight from the pros. Is there a better approach to this all?

[Tactilis]

Magnified excerpt of your above image showing the defects

 

 

58 minutes ago, TREBoy said:

My process was: opening ClipStudio, deleting all layers non transparent, making the texture, saving as PNG, moving to Paint.NET, finishing the texture up, saving as DDS. But apparently there's an issue in the process in ClipStudio that made it so all my textures have a "fake" transparent background

 

Could you post a link to the the PNG that you save from ClipStudio, i.e. before you make changes in paint.net

[TREBoy]

I had to downscale the image so I'd be able to send it here, and it made me realize something. If I export as PNG from ClipStudio, it will have the "fake" transparency issue, but trying the layer merge method leaves no artifacts. This makes me think the artifacts were left there from the DDS compression of the weird Alpha channel, which is a shame, since I made the issue of not having the PNG copies of any texture besides the first one. I'm leaving the original texture here in case you still want to take a look at it.

Subranceia.zip

[Rick Brewster]

It sounds like ClipStudio is using transparent white (#00FFFFFF) instead of transparent black (#00000000).

 

When PDN does any alpha blending or compositing, any transparent pixel -- regardless of the values in the color channels -- will flatten to transparent black. It's how the math works out. All transparent pixels are mathematically equivalent and lose their "color identity" as they move through the rendering pipeline.

[TREBoy]

Right, it's really good to know there are 2 kinds of transparent. Tbh, I'm pretty much illiterate when it comes to more technical image matters, so anything related to Alpha is quite the mystery to me. 

 

Do you think there'd be a way to set CS to use transparent black instead? Also, would you happen to know why transparent white causes issues in 3D rendering (or at least in a DDS-based 3D engine like The Elder Scrolls games)?

 

I would very much like to keep using ClipStudio for this type of work, so I guess I'll just convert the transparency before converting to DDS so there'll be no artifacts like the ones mentioned.

Edited Sunday at 05:18 PM by TREBoy

[Rick Brewster]

16 minutes ago, TREBoy said:

Do you think there'd be a way to set CS to use transparent black instead?

No idea. This is a Paint.NET forum. You'd get a better answer on a forum (or Discord or whatever) dedicated to ClipStudio.

[Tactilis]

1 hour ago, Rick Brewster said:

It sounds like ClipStudio is using transparent white (#00FFFFFF) instead of transparent black (#00000000).

 

Yes, it is.

 

Here's the supplied Subranceia.png showing that the fully transparent pixels are transparent white.

 

 

 

@TREBoy you could do this:

1. Open Subranceia.png in paint.net

2. Press Shift+S to activate the Magic Wand tool

3. Set the Tolerance in to toolbar to 0%

4. Hold down the Shift key and click on a transparent pixel in your picture. This will do a global select of all  transparent white pixels.

5. Press Delete to do Edit > Erase Selection

6. Press Ctrl+D (or Esc) to do Edit > Deselect

Now, all the previously transparent white pixels will be transparent black:

 

 

 

There may be a plugin that can do this in one step. If there is, I'm sure someone will be along soon to advise.

 

[Red ochre]

1 hour ago, Tactilis said:

I'm sure someone will be along soon to advise.

https://forums.getpaint.net/topic/111800-transparent-to-transparent-black/  🙂

[TREBoy]

4 hours ago, Red ochre said:

https://forums.getpaint.net/topic/111800-transparent-to-transparent-black/  🙂

Unfortunately, that would only solve the transparent white background issue, and not the artifacts one. The background one can be solved by simply merging the current layer to an empty one. Thanks either way.

 

6 hours ago, Tactilis said:

 

Yes, it is.

 

Here's the supplied Subranceia.png showing that the fully transparent pixels are transparent white.

 

 

 

@TREBoy you could do this:

1. Open Subranceia.png in paint.net

2. Press Shift+S to activate the Magic Wand tool

3. Set the Tolerance in to toolbar to 0%

4. Hold down the Shift key and click on a transparent pixel in your picture. This will do a global select of all  transparent white pixels.

5. Press Delete to do Edit > Erase Selection

6. Press Ctrl+D (or Esc) to do Edit > Deselect

Now, all the previously transparent white pixels will be transparent black:

 

 

 

There may be a plugin that can do this in one step. If there is, I'm sure someone will be along soon to advise.

 

I ended up going with this solution, though for the DDS artifacts 0% on the Tolerance wasn't exactly enough for the job. Had to crank it up to around 50% for it to get all the white pixels and not mess up the rest of the texture. 

 

Thank you all so much, never saw a forum so quick and helpful!