This is a method:
First draw some fireball sprites (moving up, down ,left , right and between depending on how smooth you want it to move).

Remember: Yellow on the inside, then to orange and red on the outside.
Move these sprites accross the screen.

Here is another method:
Use area sampling to generate fire (These techniques should really be written in assembly).
You will have to set a specific palette though.

Just FYI... there's lots of commerical "Pyrotechnics" packs available for $$$. I don't remember who makes them but a little internet search should find something.

Also... if you're attempting to do color-additive alpha blending (a common effect for explosions), your best bet is to use D3D's Immediate Mode, so that you can get hardware acceleration. I believe someone (I think his name was Tobias?) wrote a gamedev.net feature article on this.

Hope it helps...

Mason McCuskey
Spin Studios
www.spin-studios.com

I plan to add the two pixel color values together if that's
what color-additive alpha blending means.

I never used palettes before, but if I create some B/W shapes
with an spray or airbrush, it is easy to just load a
red,orange,yellow,white palette into this image and everything
will look ok?

-Tank2k

I saw the following on the hosted site called Java Extreme. This URL has a pretty sweet particle system explosion applet, and there is Java source code for it on there.

I'm not sure if this is really what you want, but if you want algorithmic explosions, this is probably a good place to start.
http://www.gamedev.net/columns/features/diariesandsites/javaextreme/physics.htm

Good luck...

------------------

-Kentamanos

I just found out you can do this with Adobe Photoshop:

1. Create a new document in RGB mode.

2. Use the airbrush to paint some simple black dots on
a white background.

3. Go to the mode menu and change it to Indexed Color.

4. Go to Color Table... under the mode menu and select a
color table (a palette) called Black Body. This is a
256 color palette with colors going from black-red-orange-
yellow to white.

5. Click OK.

6. Your dots should now look like hot, white-centered
fireballs with yellow-red outer edges on a black background.

I also have Paint Shop Pro, so I saved the bitmap and the palette
to a file and loaded them, and there was hardly any difference.
However, I think bitmap looked somewhat better in Photoshop.

To get it to work in PSP, you have to Decrease Color Depth to
256 colors (8-bit) and then goto Colors -> Load Palette
and make sure you have Maintain Indexes selected when loading
your palette.

I don't know where this Black Body palette comes from (if you
can't find it in your directories), but if anybody wants it, I
could try to email it. It is a standard Microsoft PAL file, so
it should work in most graphic programs.

-Tank2k

[This message has been edited by Tank2k (edited September 17, 1999).]

I would like to create some 2D explosions, and was wondering
if anyone could offer some advice on how they would first create
the graphics, such as a simple fireball? Do you do it all by hand,
or for example, is there an explosion algorithm perhaps in C/C++
available that I could run to generate a couple frames?

Also, can anyone offer techniques to speed up explosions (other
than writing it all in assembly) that are drawn translucently
where you can still see the background pixels under the explosion?

-Tank2k

Make sure that you don't use up all 256 colors in your palette (at least when you're in a 256 color screenmode).

I think that you want to use other colors than red->orange->yellow->white.

Try using 64 colors. 64=white 0=black, than you have 192 colors left.