particle effects

General Discussions
#1

I’m trying to get some nice particle effects for a game. I’ve played around a bit and I am having a lot of trouble getting anything that looks nice. I then decided to mimic one of the effects I found in a particle system tool. They combine these two images:

http://n4te.com/temp/glow.png

http://n4te.com/temp/flare.png

Here are my results:

http://n4te.com/temp/particles.png

On the left is the particle system tool, with a feature called “intense” enabled. The middle is the same tool but without “intense”. The right is what I have implemented using GL_SRC_ALPHA, GL_ONE.

How could I mimic the “intense” blending that the tool is doing? I’d like to do it as simple as possible.

Also, any other tips on how to get nice particle effects would be helpful.

#2

aren’t the glow and blur post processing effects those that make the particles look shiny and such.

#3

Additive blending, which is either glBlendFunc(GL_SRC_ALPHA, GL_ONE) or glBlendFunc(GL_ONE, GL_ONE) depending on your needs.

I just saw you already did that. Anyway, just do it ahead-of-time, and render the resulting texture.

#4

Yeah I’d mess around with blending combinations, and if you can’t get it exactly then you can always create what you want in Photoshop and just draw it.

#5

Yeah, the thing is, you’d have to render the result to a texture, because you probably don’t want to render the ‘combination’ through additive blending. You’d quickly reach ‘white’ pixels. One benefit of additive blending is that you don’t need to depth-sort your particles. Have fun.

#6

Yeah, that’s a good point. For this reason my particle systems are almost always just a Sprite being drawn over and over, with color changes (glColor4f), rotations, and scales applied. This works pretty well for mostly anything, and there is very little in-engine processing.

#7

I am trying, but it isn’t working out so far. :stuck_out_tongue: I hadn’t much luck with nice looking effects by creating my own assets in Photoshop, so I looked around at some particle tools. I was hoping to get somewhere using their assets, but even that failed! I guess I’ll play around in Photoshop with the spiky particle and try to get it to blend like I want. Does anyone know how to mimic GL_SRC_ALPHA, GL_ONE in Photoshop?

I’ve built a pretty sweet particle engine tool, which I’ll share when it is done. I guess if you’re bored you could take a sneak preview. I might as well ask how you guys feel about my triangle-based particles. I use degenerate triangles and do the translate/rotate/scale math to render with glDrawArrays. I was a little worried (on Android) since it is a bit more work than just point sprites, but I’m hoping it isn’t that much worse. Haven’t had a chance to test it yet.

#8

Just try out the different opacity options (put the two in different layers and then give the top one opacity and mess with Multiply, Overlay, etc.).

#9

I did. I posted an image showing the results I get with GL_SRC_ALPHA, GL_ONE. I believe GL_ONE, GL_ONE looked the same. Using the same images, it doesn’t look as good as the particle tool’s blending.