Background color in dds files

Caboose · #1 02-04-2005, 11:48 PM

Pretty sure its a basic question, but when ur selecting an image from the dds file, ur not just selecting the image, but ur also getting the background color because ur selecting using a rectanlge shape. In most of the dds files i see the background as either black with RGB values being 0 or grey with RGB values being 71,72,71. Does the game know not to pick up on the background and just the pic, or are there certain colors the UI knows not to display and show as being transparent?

ger · #2 02-04-2005, 11:51 PM

It's a display bug. If you use a DDS converter to change those images to PNG or PSD/PDD you'll notice that the grey/black "background" actually turns into the transparancy it's supposed to. For some reason working with DDSes in their native format, or converting them to TGAs, doesn't display that transparancy correctly.

Quib · #3 02-04-2005, 11:56 PM

It's not a display bug. Actually I prefer the native DDS style/TGA version of transparency. In Photoshop, transparency for DDS and TGA is a channel (alongside R G and B layers) and can be edited per pixel really easily.

So transparency isn't showing incorrectly, you're just used to it being displayed differently.

So, it's this alpha channel that EQ2 uses for transparency, the color of areas that are 100% transparent doesn't matter, since you won't see them. Personally, I always go with a 0,0,0 black since the texture compression can cause areas to bleed into eachother a little. When people use a converter or make the 100% transparent areas white, things seem to have slightly highlighted edges because the white bleeds over, black makes it a little darker at the edges, but this isn't usually a bad thing.

Quib

Edit: Attached a screenshot of the alpha channel for the default window_elements.generic.dds file. Ctrl+4 is Photoshop's shortcut to get to the alpha channel. Ctrl+~ to get back to normal RGB.

Caboose · #4 02-05-2005, 12:17 AM

So it doesnt matter what color i make the background, i coulduse whatever helps me see better even, what matters is if make an alpha layer? As long as theres an alpha layer the background will be transparent?

Quib · #5 02-05-2005, 12:22 AM

If you're using Photoshop, the easiest way to make sure it's set up properly, is to copy over a DDS file that already has an alpha channel (any of the default EQ2 UI DDS files), then paste your image over it and edit the alpha channel accordingly. I don't know how to "make" an alpha channel if the file doesn't already have one.

Notice I said colors can bleed over, use whatever color you want for the background while working on it, but I suggest making it 0,0,0 black before you save your final version. If you use hot pink for the background, it could bleed over onto the edges of your image due to DDS's compression.

Quib

Caboose · #6 02-05-2005, 12:40 AM

K, i get how it works now. And to edit the alpha layer using one from another dds file. I can use black to paint over the white areas used for the rgb layers and erase the shape of the image i made? Or a white paintbrush?

taco-man · #7 02-05-2005, 01:05 AM

Quote:

Originally Posted by Quib

I don't know how to "make" an alpha channel if the file doesn't already have one.

just select something with the selection tool and then do Select -> Save Selection and then name it Alpha 1. now when you go in to the channels tab, TADA you have an alpha channel you can edit all you want.

Corren Silverfir · #8 02-05-2005, 02:28 AM

Ok my 2 cents worth.

When I make a DDS in Photoshop I create whatever image I want and make my background transparent.

Then I save as , select DDS, in the popup window I choose 3 which saves the alpha of the transperant layer for me.

Now when I reopen the dds it will be a white background but the dds knows it's transparent and when i use it in my mods it stays transparent.

Also remember in order to save it you have to make your High and width of the canvas the same, example : 512 pixels x 512 pixels

taco-man · #9 02-05-2005, 02:47 AM

Quote:

Originally Posted by Corren Silverfir

Also remember in order to save it you have to make your High and width of the canvas the same, example : 512 pixels x 512 pixels

not only does the width and height have to be the same, they have to be a power of 2, i.e. 2,4,8,16,32,64,128,256,512,1024,2048,.....

ger · #10 02-05-2005, 07:30 AM

Quote:

Originally Posted by taco-man

not only does the width and height have to be the same, they have to be a power of 2, i.e. 2,4,8,16,32,64,128,256,512,1024,2048,.....

Ah ha! Now this time I know I'm not smoking crack (like I was with the display thing—that still bugs the crap out of me

) The width and height don't have to be the same, but they do have to be powers of two. The new frames in my target/implied target window are in a 512x16 DDS and they work just fine.

Corren Silverfir · #11 02-05-2005, 12:28 PM

Quote:

Originally Posted by ger

Ah ha! Now this time I know I'm not smoking crack (like I was with the display thing—that still bugs the crap out of me

) The width and height don't have to be the same, but they do have to be powers of two. The new frames in my target/implied target window are in a 512x16 DDS and they work just fine.

Yes my bad powers of two

Humudce · #12 02-05-2005, 01:29 PM

The biggest problem I had with my background graphic for my Blue Dragon Knowledge Book mod was getting the semi-transparency to work on the wings. I saved it in I don't know how many different variations of dds, and finally got one to work. The format I ended up using was DXT3. Any other formats did not apply the transparency color correctly to the wings and they appeared completely solid and not semi-transparent as I wanted them and as they showed up in my graphics program.