PS transparent on texture edges?

i have read that on textures for buildings like brick etc it is good to have several pixels of transparency around the edges.

i don't know how to do this. I can get it by makeing my image say 510 x510 and pasting it into a new image of 512 x 512. when i flatten the image the transparent canvas is now background white. any other way i know how to do that i try this i end up with the same result. like makeing layers that are transparent. all ways goes to white when i flatten.

thanks,
sharron

Hi Sharron!

This is a very bad idea, since it will make the entire wall vulnerable to the infamous "Alpha Sorting Bug."

In other words, from certain angles, things with transparency (trees, grass, property lines, "privacy tape," cars with transparent windows, avatar hair that uses transparency... anything with an alpha channel,) will appear to be in front of your wall, when they should be behind it.

It's bad enough with a window. But, unless you want distant trees to look like they are in your building, don't do this.

Hope this helps!

edited to fix misspelling of Sharron's name. I'm so sorry, Sharron!

Plus, at least until they get around to finishing off the new shaders, it will mean you cant apply any form of reflectivity or bumpmapping to that texture.

Oh, i read in a texture tutorial or post somewhere (i have read so much i can't remember) that you do this to keep the texture from wrapping on the edges. i think in the article or post where i read this the writer used a picket fence picket as an example.

so, i don't know how to do it anyway.

thanks,
sharron

I'm not sure it's right for a picket fence texture either, although it could be I guess.

But a picket fence is different to a normal wall, in that it has alpha in it already, for the gaps between the posts (pickets?) that you can see through.

For general tips about transparency - the techniques are the same whatever you're making, read the stickies at the top of the forum about transparency and alphas (they're essentially synonymous, although transparency is how you see (or don't) and alpha is how you make it to be precise).

This is a different story: If your making a texture with transparency, like a white picket fence, in any direction you dont intend the texture to tile, you should leave a bit of transparent border, otherwise you will get some artifacts around the edges. But for brick walls and stuff, don't do it.

thanks Reitsuki,
now i understand. I was reading with 50% or less retention rate and only remembered part of what i read. It makes sense now.

thanks to all of you that replied.

sharron