Some more GZDoom related questions

[Patrick]

here goes. So what exactly is an alpha channel? How do I use them in GZDoom, and what could I use them for?

[Gez]

Patrick said:

here goes. So what exactly is an alpha channel?

Level of transparency.
http://en.wikipedia.org/wiki/Alpha_compositing

Patrick said:

How do I use them in GZDoom

With PNG files that have an alpha channel.
Alternatively, you can also specify the alpha property of actors with the Translucent renderstyle. Also the strength of a PowerInvisibility powerup in translucent mode. And linedefs have their own way of getting an alpha value, but I don't remember it OTOMH.

Patrick said:

and what could I use them for?

Making stuff more visible than invisible, but less visible than opaque.

[Patrick]

This is all jargon to me (thanks for the response though.) But from your last description, is there really any need to create alpha channeled sprites/textures if I can simply apply these effects in the TEXTURES/DECORATE lump?

So how would I create a PNG image with alpha channels, what would it look like in a good image viewer/editor (like... photoshop/gimp?) and how would it look in GZDoom?

[exl]

Patrick said:
So how would I create a PNG image with alpha channels, what would it look like in a good image viewer/editor (like... photoshop/gimp?) and how would it look in GZDoom? [/B]

In Photoshop, the easiest I've found is to just have no background layer, like so:

When saved as a PNG, Photoshop will convert the transparent parts into an alpha channel automatically. In this case the smiley would have a fuzzy outline when used as a texture in GZDoom.