Quick question concerning flare and targa and transperency


(ndnchief) #1

I use Pub 2.25 and I was making a flare type bullet. I created it in Photoshop Made the background black, with the flare centered and fading to black. I was under the impression that the game engine views black color on Targa as transparent, but when I test it out I can see the black background. Can anyone help me out, what am I doing wrong?

The NDN…


(OOPz) #2

TGA (and in fact most transparent textures) store an extra layer (RGBA) where A is the Alpha channel… youll need to go into photoshop/paintshop and add an alpha channel to the image, these can be a pain in the butt… you often have to add the channel, then save the channel to the alpha layer then… save the image, but once youv figured it out its easy…

Tip, make the RGB data with a view to cutting out the shapes afterwards, e.g. If your making a glowing halo- Make the whole image bright red (for example) then add the alpha channel to cut out the shape you want… because if you start with a white sheet then add a soft red blob in the middle it will appear as a red dot with a faded white outline in game.


(ndnchief) #3

I have tried, but cannot figure out how to save a targa image with an alpha channel in photoshop. It cant be that difficult. I am familiar with the program, I know about layers and channels, but just cant get a grasp on it. Can some one please give me a quick lesson, Step1, step2, step3, etc… Just quick and simple, Just to get me on the right road. I am using PhotoShop 6, If you can help thanx…

NDNChief…


(Ben) #4

-Blender looks as transparent all black parts of tga images if in the paint buttons window when you have pressed F on 3D window and have selected Add button.If you select alpha the tga image must have tranparent parts.I dont use photoshop, but the transparent parts can be obtained in this way.create a transparent layer as background.Then add another one with the texture,select the parts you need as transp and cut them.Then merge layers and save it as a tga.


(lizard809) #5

here’s an image that tries to explain

http://mysite.iptic.com/cluh/alpha.gif


(wiseman303) #6

Ben, that’s not true. a TGA needs a proper alpha channel. black only works if you choose ‘add’, and in that case, the image does not have to be a TGA.

Transparent areas of an image show up as a checkerboard pattern in the image window, this is true for both GIMP and PhotoShop.

I’m more familiar GIMP than PhotoShop, but the way I make a transparent texture in PhotoShop is to choose ‘transparent’ for the background color when creating a new image. Then the alpha chanel is already created and I just paint normally.

In GIMP, you can do it that way, or right click in the image window and choose layers->add alpha channel. Then to get chroma-key like transparency, right click in the image window and choose filters->colors->color to alpha… set the color you want to make transparent, and click OK. Then save as TGA.

For you’re flares ndnchief, I would save the image as JPEG, and set the paint mode to add. This will get a similar effect to an alpha channel without all the trouble. JPEGs can also be compressed to a much smaller file size, so your game will run faster.


(ndnchief) #7

Thanks everyone, MortalNME, Ben, Lizard809(Thanks for gif), and Wiseman303. Everyones information helped me to figure it out. Its great to get such good feedback. I am satisfied with my results finally, and all because of your replies… Thanks again, and I say again, I really appreciate everyone taking the time to reply…

NDNChief…

P.S. I will try your sugggestion Wiseman303, about saving as jpeg but still achieve same affect, always good to keep filesize down…

Thanks again :smiley:


(Ben) #8

-Wiseman!!
I wrote:

Blender looks as transparent all black parts of tga images if in the paint buttons window when you have pressed F on 3D window and have selected Add button

you wrote:

Ben, that’s not true. a TGA needs a proper alpha channel. black only works if you choose ‘add’, and in that case, the image does not have to be a TGA

-We are saying the same thing.
-I don’t understand why you dont like my way of making transp. tga.Yours is valid too.


(wiseman303) #9

Oops, I misread your post. Sorry, I’ll try not to do that again.
I was distracted when you specified TGA. Add works for any image format, including TGA and JPEG.
Sorry again for the misunderstanding.