Fire!

[Dan]

Seems like most people never mention a very important problem with particles in 3D... if you have a z buffer when you render particles, you will almost definetly see glitches where a raticle rendered earlier will make a particle rendered later partially or completely invisible. In that case disabling writing to z buffer somewhat solves the problem. However, imagine you have a particle system with a very thick smoke, and another system right behind it, say a fire. If the smoke system is rendered earlier than fire you will still see fire through the smoke, because the smoke doesnt write anything to z buffer. How would you people solve this problem? you wouldn't sort every particle by the distance to camera, would you?

[Huehnerschaender]

@ILovePascal:
If you use a texture from a real fire explosion, it will look best.
Make it semitransparent. About half transparent in the middle and then the more to the edges of the texture, the more transparent it gets.

@Dan:
This is exactly how I do it (see above). Using semitransparent textures will makes it nearly regardless in which order the particles are displayed.
You can do the following to achieve an effect without obvious glitches:

You want to draw a fire/ an explosion at position x/y/z with a radius of r.

Spawn particles randomly in radius r around the position, defining the starting transparency more transparent dependend on the distance to the midpoint (points which are more far away are more transparent from startup).

I will show an example when we have a particle engine in DanJetX

Greetings,
Dirk

[Dan]

Huehnerschaender,
I will try to code the problem and show it to you later...
If I make a particle engine in DJX with instancing then you wont be able to sort each particle easily... unless I somehow combine instancing with sorting.
The problem I'm talking about will only appear when you have a complex system with lots of different particles, some of them rendered with blend mode and some just semitransparent.