The right PNG format ...?

Target Platforms Mobile
1

Hello,

I’m having some trouble with PNG graphic tools, as they seem to be randomly correct with iPhone PNG format.

I’m using these PNG for AtlasTextures (so no PVRTC, but the best possible compression).

What tool do you use to save your PNGs in order to have a correct iPhone adaptation ? Using which settings ? (interlaced ? 8-bit ? 24-bit ? etc)

Do you even use JPGs on import ? Seems like it’s not supported by the iPhone either, at least when I try to pack it into a TextureAtlas.

How do you create your iPhone texture atlases ? (with and without alpha channel)

Thank you :wink:

2

I just use Photoshop’s Save For Web, saving 24bit png’s.

3

Thank you Smag.

No interlaced ?

4

Nope. The way I understand it, interlaced is used to make the image appear progressively on the web. I don’t think it has much use in an iphone app.

5

Ok that’s perfect. Thank you.

I’m still curious if everybody do use PNG RGBA 32 textures in their TextureAtlas here ?

It’s so huge for iPhone …

6

The original format you use is irrelevant; the only thing that matters is what the texture is set to with Unity. i.e., uncompressed 32-bit RGBA, PVRTC, etc. There is no PNG format for textures, so PNG compression is never used, except for your source textures, but those only exist in your project and never on the iPhone, so it’s pointless. Likewise, JPG is useless (and lossy, so don’t use it for anything). You should use the format that gives you the most control, which is PSD, since you can make alpha channels, and keep the layers and so on. Use the highest compression you can get away with that still looks OK. If that’s PVRTC 2-bit, use that. If that looks bad, try PVRTC 4-bit. If that looks bad, use uncompressed, but only as a last resort.

–Eric

7

PSD seems to be fine for my perimeter, thanks for the tip Eric.

But still, I was asking this question because I’m experiencing textures bugs depending on the 3rd party tool I encode the PNG with.

Illustrator : the textured character is ok.
Photoshop : he’s all blackened.
GIMP : the same.

And it’s the same business for other textured elements : I have to choose the right software coupled with the right Unity compression with the right format.

Didn’t find that correct equation yet, but with the exact same TextureAtlas generation code, I have varying results when I change that 3rd party-to-Unity workflow.

:confused: