multi TGA export

[Patrick Connor]

@Chris B

Please investigate this

[Sean P]

19 hours ago, MikhailPo said:

Hello.

I was tested exporting to TGA format with Alpha channel in version 1.7.3 and had some problems with it.

TGA header has information about bytes per pixel equals 4, but ImageDescriptor field hasn't any information about bits for alpha channel (it is equals 0). With it some programs can't open exported TGA files

File format reference - https://www.fileformat.info/format/tga/egff.htm#TGA-DMYID.2

 

Hi MikhailPo,

What applications are failing to open Affinity exported TGA files?

[MikhailPo]

22 hours ago, Sean P said:

Hi MikhailPo,

What applications are failing to open Affinity exported TGA files?

Hi Sean,

It's inner software in my company. It was created across TGA documentation and works well with TGA files exported from Gimp and Photoshop.

In other viewers it works fine (Photoshop, Gimp, Blender, MacOS default viewer, etc.).

I can acquire request for modification our soft but I think that better for Affinity is support TAG format correctly.

Example in attachments:

demo1.tga Header(hex) 00 00 02 00 00 00 00 00 00 00 00 00 31 00 31 00 20 20 (Affinity Photo)
demo2.tga Header(hex) 00 00 02 00 00 00 00 00 00 00 00 00 31 00 31 00 20 08 (Photoshop, no RLE compression)
demo3.tga Header(hex) 00 00 02 00 00 00 00 00 00 00 31 00 31 00 31 00 20 28 (Gimp, no RLE compression, origin top-left)
demo4.tga Header(hex) 00 00 02 00 00 00 00 00 00 00 00 00 31 00 31 00 20 08 (Gimp, no RLE compression, origin bottom-left)

As you see last 4 bits (0x0F) have information about alpha channel size (8).

demo4.tga

demo3.tga

demo2.tga

demo1.tga

Edited December 10, 2019 by MikhailPo

[Sean P]

Thanks for that MikhailPo,

I've passed that on to development to be investigated, thank you.

[MikhailPo]

On 12/10/2019 at 5:18 PM, Sean P said:

Thanks for that MikhailPo,

I've passed that on to development to be investigated, thank you.

Hi, Sean P.

Is there any news about fix tga export?

[ashf]

Alpha channel behavior has serious problem when doing round trip editing with other apps.
Needs improvement to handle straight alpha.

 

[MikhailPo]

One month left before the anniversary of the defect 🎉

All this time I have to use GIMP to work with TGA 😥

[MikhailPo]

Release 1.9. TGA works (alpha bit is correct)! Thank you!

[Sersch]

Hi,

I'm running into a small inconvenience with the TGA export. I'd like to use Affinity Photo for editing Quake 3 textures, because TGA is the only format that Quake 3 can use for textures with alpha channels.

The texture loads correctly in-game, but the game's console prints the following warning:

"WARNING: '[path to texture]' TGA file header declares top-down image, ignoring

I can fix this by exporting the TGA from Gimp instead. During export, Gimp lets me choose between Bottom left and Top left for the Origin setting. The error goes away when I use Bottom left.

You can find the code section in Quake 3's source code that's related to TGA rendering here, starting in line 1121. The error message is in line 1354. Maybe this is helpful in some way.

[Patrick Connor]

@Sersch

Welcome to the Serif Affinity forums  

That's very helpful thank you