Pie in the sky query here, but I was just wondering if stuff like bump mapping and normal mapping, motion blur, has been used for creating more realistic explosions, (which afaik, are mostly based on billboard textures), to had a bit more 'depth' to the overall effect (think a mortar hitting soft ground).

I've had a quick look into this myself recently but havent gotten around to actually trying anything as yet. What I've come up with is a presentation from a guy at Unity and a Direct3D sample showing an example implementation.

It's a neat idea and a very pretty effect, but I'm short on time with University work at the moment so I haven't had a chance to give it a blast.

Explosions are also something which I have been thinking about recently. I was quite impressed with the ones in this video:

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On the Ogre3D forums the author gave a quick description:

http://www.ogre3d.org/forums/viewtopic.php?f=11&t=56844

The main fireball is using real geometry rather than particle systems and I think it looks good. Also kind of similar to the way Quake 2 did explosions.

I'm thinking to define the fireball meshes procedually, though.

You mean explosions like in this game?

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Yup, I was spending a week trying to reproduce something a bit similar, with no success. (You can check yourself in my signature: it's like shit-confetti, but the muzzle-flush is acceptable)

I guess a good artist and a good particle editor would suffice.

Assuming you're talking about "normal" explosions, like an oil-drum or a tank brewing up, there's some important little bits to remember.

1) Light isn't additive, at least not like you get from adding orange circles over each other until they saturate to white. Making your textures additive does brighten them up, but not in any way that's at all realistic, especially if you don't use the "screen" blend mode to draw the additive. Make the colours bold but only slightly translucent.

2) What most seem to miss is that in really good looking roiling explosions, there is more black than orange. Unburnt fuel, soot and smoke do more to hammer home the reality, but getting it to move properly can be a challenge.

3) Make the particles move properly - basic interation with each other works wonders, but don't overdo the math as you still wants lots of them.

Quote:Original post by Rubicon
2) What most seem to miss is that in really good looking roiling explosions, there is more black than orange. Unburnt fuel, soot and smoke do more to hammer home the reality, but getting it to move properly can be a challenge.

It is also important to note that the light from such an explosion is coming from INSIDE of that cloud of soot and unburnt fuel, it not from the surface.

I did my muzzle flash in two passes: first I rendered the system with an orange color and bigger particles, then rendered again on top of the previous with white, smaller particles.

This way it saturates to white in all the volume, but has the orange glow at the edges. That gives a pretty good look (I spent hours just with looking at real tank muzzle-flashes). But I guess it's only okay for short, intensive explosions. But maybe if the intensity of the white pass would be reduced in time (to zero), it could be used for any explosions.
I used the default GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA blending mode.

I was thinking about a three pass method: black smoke - orange glow - white stuff

The hard thing is the soil explosion, but I guess some stretched white smoke particles, and some good soil-particle textures (and a good artist) would do.