Designing Particle Textures for Unity

I think the best place to look to understand how to edit particles would be here http://unity3d.com/support/documentation/Manual/Particle%20Systems.html Then it would be a case of finding the right material shader with the right textures.

We have used a photoshoped image of a circle with transparency, exported as a PNG and applied that to a new material, we chose the shader, Particles/Additive (soft) and that has made a very nice sphere particle.

If you combine a mesh particle emitter and particle animation effects, then make a few of them emitting at the same time from an empty object, with a script on that activates all your particles (you can also script a few changes to the particle emitter to add some extra effects) parented to your player. With enough time and effort you can make something like final fantasy. (better watch out for performance issues tho lots of fancy particles can be heavy on the system)

You could download the detonator package here and look at the example prefabs in it, and read the documentation :-).

As for customizing the capabilities of Unity's built in particle system, you could look at using the Nvidia PhysX developers tools to create the features you want and call them externally using C#. You can modify the particles to fit your needs both aesthetically and behaviorally.

http://developer.nvidia.com/object/physx_partners.html

To make a basic particle texture in photoshop, etc..., add a transparency layer (otherwise known as an Alpha layer,) set parts to be transparent, and save as a PNG instead of a GIF (gifs can fake transparency, but can't get partials for fog and the smooth fall-off we need.)

I use gimp, so I: fill the image to black, paint with whatever colors using the brush or sprayPaint tool (the ones that give feathered edges) Layer->AddAlpha, Layer->ColorToAlpha and tell it to make black transparent. You should see a checkerboard pattern in the transparent parts. In Photoshop, I'm told you select Transparency first, and it will automatically fill in the parts you paint. When you view them in a normal pictureViewer, they will look all blobby -- that's normal, the viewer isn't using your transparency.

To use your texture in Unity, create a material, select that image for your material and select the Particles/AlphaBlend shader (or try other Particle shaders.) In the ParticleEffect, down in ParticleRenderer, pop open Materials and select yours.

Two schools for the texture color: One is to use the exact color you want, and leave the unity colors as all white (which means "no change" in this case.) Two is to use mostly white/grey/off-grey, then, in Unity, select the colors you want. For example, green for poison, then reuse it with white for mist.

To make Animated textures, do the same thing, but, for example, use the 64x64 corner of a 256x256 texture (sticking with powers of 2 is a good idea.) The most common trick for Cut&Paste is to create several layers (copies of the 1st,) move/rotate them, then merge them all down when finished. But, try using one texture and select RndRotation and AngularVelocity, RndVelocity and maybe SizeGrow(in the Animator) -- identical overlapping spinning floating particles can look like chaotic swirls.

Using layers to move things around (think about sliding around a bunch of transparent slides until they overlap the way you like) is a generic topic -- not specific to particles -- and should be easy to find.