Paste images into RGB channels (Channel packing)

[NatCLK]

I'm a 3d artist for games and I often need to create ORM textures. ORM stands for (ambient)occlusion, roughness, metallic. The ambient occlusion map goes into the red channel, the roughness map into the green channel and the metallic map into the blue channel. I never managed to do this in Affinity Photo, working with RGBA channels in photo looks very complicated. In photoshop it's so easy, I just have to copy the texture map and paste it directly onto the channel.

Is there a way to achieve this? It would be great if Photo had such an easy workflow for managing channels, in PS it's as easy as copy/pasting anything into them.

Edited August 1, 2021 by NatCLK

[kirkt]

 

Channel packing in PS, GIMP and AP.

kirk

 

[NatCLK]

THANK YOU! I wouldn't have figured that out by myself. Anyways, goodbye photoshop. 😁

Edited August 2, 2021 by NatCLK

[kirkt]

I know there is also a discussion in a video from James Ritson, the AP tutorial guru, about channel packing for 3D applications, but I cannot remember exactly what video addresses it (it could be a general video about Channels, for example).  Here is a link to the AP tutorials list:

kirk

[kirkt]

Also see:

https://www.jamesritson.co.uk/resources.html

and specifically, the "JR Channels Macros," which include automation for channel packing in AP.

kirk

[NatCLK]

Thanks a lot! The JR Channels Macros look really useful indeed. 

Edited August 2, 2021 by NatCLK

[ambersand]

It's a bit sad that I can edit a channel with the tools, select all in a channel, but neither copy nor paste it to the active edit channel in the same image or another open one.

Let me point out that AP is now very close being able do this, just please enable the paste. Please! (of course a warning might occur if the copy has more bits than the expected 8bit)

P.S.: I tried the workaround with Spare Channels, it's just too annoying and wasting A LOT of time.

[Lisbon]

What is channel packing?
Just copying and pasting channels between documents, is that it?

[telemax]

30 minutes ago, Lisbon said:

What is channel packing?
Just copying and pasting channels between documents, is that it?

Channel packing is needed to create an ORM texture. Or to store 3 different masks in one texture.

Target: get one file, with 3 or 4 grayscale textures inside.

[Lisbon]

25 minutes ago, telemax said:

Target: get one file, with 3-4 grayscale textures inside.

But for 4 grayscale textures you need 4 channels, right? Like CMYK.

[telemax]

1 minute ago, Lisbon said:

But for 4 grayscale textures you need 4 channels, right? Like CMYK.

Right, not CMYK, but RGBA.

[Lisbon]

52 minutes ago, telemax said:

Right, not CMYK, but RGBA.

Thank you telemax.

 

If I understood correctly, I think "channel packing" can be done quickly in Affinity Photo.

First download the macro at the end.

Document_A will be the ORM texture.
Document_B is a grayscale texture.

1) Create document_A and add a pixel layer filled with any colour.
If document_A already exists go to step 2.
2) Run the macro on document_A
3) Copy Document_B
4) Paste on document_A over R, G or B

When finished flaten the document.

In this example, I pasted Document B on the group corresponding to the green channel.

Split RGB.afmacros

[ambersand]

Channel Packing as you describe is a different workflow, it will not work efficiently with EXISTING 4 channel / 32bit textures.

But, it is an interesting workflow for texture artists creating NEW textures. Thanks for pointing that out.

Sorry about the confusion and clearing it up so detailed. Thanks.

[Mike_A]

What is telling is that in the first video answer posted above the guy takes around 2.5 mins to demo in Photoshop - and 5.5 mins to demo in AP  : )