PNG alpha displays incorrectly

General questions and troubleshooting SOFTIMAGE©
IslandDreamer
Posts: 58
Joined: 08 Jun 2009, 17:57

PNG alpha displays incorrectly

Post by IslandDreamer » 07 Jul 2013, 14:49

I don't believe this is strictly a Softimage issue, as I've seen the same result in C4D. I just hope someone here can point me to a fix.

The PNG texture maps were created in Photoshop CC (smallest, compressed). As you can see below, they render correctly but display incorrectly throughout the rest of the software.

Was there something I missed in saving them in Photoshop? Notice too how the (9 and )0 textures are correct even though they were saved in the same way.

Image

Much appreciate any insight you guys can provide!

IslandDreamer
Posts: 58
Joined: 08 Jun 2009, 17:57

Re: PNG alpha displays incorrectly

Post by IslandDreamer » 08 Jul 2013, 21:32

Lots of views, but no advice to share? :((

Lord Futzi Voldemort
Posts: 440
Joined: 06 Jun 2009, 12:01

Re: PNG alpha displays incorrectly

Post by Lord Futzi Voldemort » 08 Jul 2013, 21:51

IslandDreamer wrote:I don't believe this is strictly a Softimage issue, as I've seen the same result in C4D. I just hope someone here can point me to a fix.

The PNG texture maps were created in Photoshop CC (smallest, compressed). As you can see below, they render correctly but display incorrectly throughout the rest of the software.

Was there something I missed in saving them in Photoshop? Notice too how the (9 and )0 textures are correct even though they were saved in the same way.

Image

Much appreciate any insight you guys can provide!
Your png may have unpremultiplied alpha. PNG has also the option to use transparency instead of apha. What you see in the displa is actually what png does with color in transparent areas. It is repeating the colored pixels into the transparent areas. Since at some point the colored pixels will be multiplied with the alpha or made transparent in the areas in question (as you see in your render region), this is ok. if you want correct texture display try saving the png with alpha premultiplied, or convert it to a tga or tif.
Check here: http://en.wikipedia.org/wiki/Portable_N ... y_of_image
I'm now part of an endangered species...

IslandDreamer
Posts: 58
Joined: 08 Jun 2009, 17:57

Re: PNG alpha displays incorrectly

Post by IslandDreamer » 11 Jul 2013, 15:43

Thanks. I didn't find any premultiplied save options in Photoshop, so I converted all the textures to TIF and they now display and render properly. I usually shy away from TIF textures because they tend to result in larger file sizes.

User avatar
Superpositivo
Posts: 123
Joined: 18 Feb 2013, 13:48

Re: PNG alpha displays incorrectly

Post by Superpositivo » 12 Jul 2013, 08:49

It's a known issue.
In Softimage you got 2 options to reveal the alpha channel in viewport.

1: in the Image PPG.

2: in Display Options PPG.
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