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OlaHaldor

How do I properly work with alpha channels?!

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I'm having trouble understanding how alpha channels work in Affinity Photo.

Just like TGA and DDS export, this is yet another thing that is forcing me to keep other software around to get my work done. :/

 

 

It's simply like this: I have an image file, it's got RGB and alpha channels.

I load the image in Affinity Photo, I see "composite alpha" with the list of channels, but it is completely white. It shouldn't be.

To check the file I load it in Photoshop, and see it appears as expected.

 

Where am I going wrong? Or is Affinity Photo simply not up for the task?

 

whereisalpha.jpg.77ab261977539cd34b2b616c78d25396.jpg

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AP seems to have a bit halfbaked channels support. If you create a layer mask in PS it transfers fine. If you create a separate alpha channel, it transfers fine, but you have to load it to image as selection separately. I did not find an easy way to paste channel as mask. Composite alpha seems to be quite separate from other channels..

Sorry, it has been a while since chops were the rage in PS world and I have no deeper knowledge how to work with channels. Your workflow is though common enough and there should be clear instructions how to do the thing.

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Thanks for replying at least.

I googled a lot last night trying to find a solution, but the info I found was not exactly encouraging.. 

 

I don't even know where to begin describing what I think about this workflow to pack channels for games manually is...

 

I would expect in your very intuitive apps that you'd think more about efficiency in other aspects than great tools for drawing and manipulating pixels, and let us work as fluent and smooth as possible. Going through "spare channels" is not it.

For an efficient workflow it makes no sense. It adds so many extra clicks when it could have been made into a user friendly copy-paste, and be done with it.

 

And what would I do in the example of the video, if I wanted something else in the alpha channel? It's not unusual to pack something like

R: roughness

G: metalness

B: ambient occlusion

A:  custom color mask (to change accent colors on the 3d model)

 

Imagine doing what's described in the video above 10 times. 20 times. 50... No thanks. I'm disappointed. :(

 

I hate for this to sound like an attack, I am just stumbled and don't feel like I'm getting anywhere.

Anyone official from Affinity that could enlighten me?

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45 minutes ago, Fixx said:

Composite alpha seems to be quite separate from other channels...

The composite channels are those of the entire document, a combination (composite) of the channels of all the separate layers in it. In Affinity Designer each pixel, mask, adjustment, & live filter layer (basically, anything that is rasterized) also has its own set of channels, which are shown in the Channels panel below the composite ones when that layer is selected in the Layers panel. The number of color channels depends on the color space ("color format" in AP speak), so 3 + alpha for RGB & Lab, 4 + alpha for CMYK, & 1 + alpha for grayscale.

 

For a single layer document with no transparency (like a photograph), both the composite & layer alpha channels appear as all white (because everything is visible); if you erase part of it, the alpha channels will show that. If you open a file that includes transparency, the alpha channels will show that:

channels.thumb.png.b9706cd3433ad0e4a9e290c571481109.png

The Document menu > Transparent Background option has no effect on this -- there must be transparent sections somewhere in the document.

 

Obviously, this is far from ideal for channel stacking.

 

channels example.afphoto


Affinity Photo 1.7.2, Affinity Designer 1.7.2, Affinity Publisher 1.7.2; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
Affinity Photo 1.7.2.153 & Affinity Designer 1.7.2.6 for iPad; 6th Generation iPad 32 GB; Apple Pencil; iOS 12.3.1

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This is probably OK when you create the image in Photo, but that's not the case here.

 

The image in my first post was created in a 3rd party tool which save a dedicated alpha channel for transparency inside the TGA file, which will show the image properly in the UI of the game I'm making assets for. And Photoshop sees the alpha channel.. It's beyond me why Photo can't.

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This post may shed some light on that....


Affinity Photo 1.7.2, Affinity Designer 1.7.2, Affinity Publisher 1.7.2; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
Affinity Photo 1.7.2.153 & Affinity Designer 1.7.2.6 for iPad; 6th Generation iPad 32 GB; Apple Pencil; iOS 12.3.1

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13 minutes ago, OlaHaldor said:

I've attached the file as a ZIP.

I opened the unzipped file in AP 1.5.2 on my Mac. Aside from the oblong shape & the tan colored pattern at the bottom, some of the black area is not completely black, so it is a little harder to select whatever should be transparent than I had hoped for, but if you can manage to select everything that should be transparent (presumably all the black area outside those two colored areas?) deleting those pixels should give you a composite alpha channel more like what you expect.

 

Still not very helpful for channel stacking I know, but it might be useful for something....


Affinity Photo 1.7.2, Affinity Designer 1.7.2, Affinity Publisher 1.7.2; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
Affinity Photo 1.7.2.153 & Affinity Designer 1.7.2.6 for iPad; 6th Generation iPad 32 GB; Apple Pencil; iOS 12.3.1

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Hi OlaHaldor,

Affinity Photo doesn't support alpha channels in TGA files and there's currently no plans to implement this any time soon.

TGA is an old and less and less used format and so it's hard to justify improvements here unless this was a highly requested feature which is not the case.

I've added you report to our log/bumped it so the dev team are aware of the request but don't expect changes here, sorry.

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On the Affinity Photo Feature List web page, in the Compatibility and Printing section, "TGA" appears on the Full Open or Import List. Perhaps there should be a parenthetical note included that says "(alpha channels are not supported)," similar to the notes for the AI & Freehand entries?


Affinity Photo 1.7.2, Affinity Designer 1.7.2, Affinity Publisher 1.7.2; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
Affinity Photo 1.7.2.153 & Affinity Designer 1.7.2.6 for iPad; 6th Generation iPad 32 GB; Apple Pencil; iOS 12.3.1

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40 minutes ago, R C-R said:

On the Affinity Photo Feature List web page, in the Compatibility and Printing section, "TGA" appears on the Full Open or Import List. Perhaps there should be a parenthetical note included that says "(alpha channels are not supported)," similar to the notes for the AI & Freehand entries?

Exactly!

 

 

54 minutes ago, MEB said:

Affinity Photo doesn't support alpha channels in TGA files and there's currently no plans to implement this any time soon.

Well then.. Good bye? o.O 

 

54 minutes ago, MEB said:

TGA is an old and less and less used format and so it's hard to justify improvements here unless this was a highly requested feature which is not the case.

I've added you report to our log/bumped it so the dev team are aware of the request but don't expect changes here, sorry.

It might not be requested as much as you'd like, but I and other have voiced our opinion and wishes about this before here on the forums. The same for DDS. Both are crucial for game dev.

 

TGA might not be the hottest format but it's still widely used for game dev. Affinity Photo is just the perfect price range for a lot of indie devs or students as well, looking for a cheaper alternative to Photoshop - but lack of TGA support is nothing but a huge "what the..?" o.O

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Hi OlaHaldor,

I do understand your frustration and i've passed this report to the dev team, but that's really all i can do. I'm still waiting for some feedback from their part regarding any possible developments here but with so much on their hands already (we have a small team) i didn't want to create false expectations around this. I will update this post if there's any feedback/development from their part.

 

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count me in on the need for proper TGA support.
Many game engines and other Programs rely on that file format. since its "old" it means, the specifications won´t change and thus due to the "old" status TGA is a reliable file format which is necessary for game dev tasks.
Please add it. Its simply frustrating to use other programs to get the needed result(s).


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Who does Affinity want as their user base? As of now I feel game devs are left out of the loop. I can't promise how many users they would gain by adding support for TGA (and hopefully DDS), but I dare to say it will be very interesting for a lot of people to jump on board. Besides this, I will have less of an issue to recommend Photo to others in various forums, friends, connections in the industry, modders etc.

 

It's not a great selling point when I say "Photo is awesome. It's got that MacOS flair of intuitive usability, performs great and it's affordable", and people are truly interested at this point, but I have to be honest with them, "BUT it does not support impot/export of X, Y, Z, and you need to have Photoshop handy to convert to the formats X, Y, Z"

 

Like TGA, DDS isn't evolving much.. It's a stable format. The last update for the Photoshop DDS exporter by nVidia was in 2013! ^_^

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1 hour ago, myclay said:

... since its "old" it means, the specifications won´t change and thus due to the "old" status TGA is a reliable file format which is necessary for game dev tasks.

Except that version 1 & version 2 contradict each other in at least one of the specifications regarding scan lines. The US Library of Congress sustainability project page for the format states that for LoC archiving it is "Not a preferred format. Lossless transformation to TIFF_6 recommended for final-state works."  According to the LoC page, it also does not support ICC color profiles, may be encumbered by patent claims (although they do not seem to be enforced), & has "minimal support for embedded metadata."

 

I am not disagreeing that support for the format would be useful for some users, only that it may not be as simple to implement as some might think.


Affinity Photo 1.7.2, Affinity Designer 1.7.2, Affinity Publisher 1.7.2; macOS High Sierra 10.13.6 iMac (27-inch, Late 2012); 2.9GHz i5 CPU; NVIDIA GeForce GTX 660M; 8GB RAM
Affinity Photo 1.7.2.153 & Affinity Designer 1.7.2.6 for iPad; 6th Generation iPad 32 GB; Apple Pencil; iOS 12.3.1

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I'm other game developer and now I find that I cannot work with affinity because it doesn't support alpha in TGA... I think that it must be a joke or something.

Yeah, is an old file format, a not good file format,.... but the only file format that allow thousands of video games companies... And the problem is not to convert to TGA, is that I can't import properly and I lost alpha.

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