Re: [Flightgear-devel] Particle system future

[Thorsten R. <tho...@sc...>]

> There is per particle system z-ordering, is there not?  Just not per
> particle z-ordering.  And there is per-particle system lighting and
> fogging.

No to both.

Particles come with their own shaders OSG side and we can't access them at  
all - which means we can't merge them correctly into our scene  
organization. Their lighting is never really correct, and you have to use  
lots of trickery to make it even plausible.

> If the total size of the particle system is not too great,
> which for many applications is the case, then this should be no more
> of an issue than an effect bounding object poking through an aircraft
> model.  The modeller just has to fix it.

That's the point - it can't be fixed. It can be sort of hidden but without  
access to the underlying effect it can't be fixed.

>  For much longer
> applications, such as space shuttle contrails, then segmental blocks
> of particles or a super long effect might work better.  However the
> lateral displacement of the contrail due to wind that is present in
> the particle system might be difficult to model in a effect.

It's a one-liner in the vertex shader to displace something.

> Emmanuel
> and many other aircraft developers have used the particle system to
> good effect, I don't see a need to invalidate that work.

So have I - but it's a dead end which we can't ever merge into our scene  
properly. So my view is we need to get out of the corner and move to  
something we have control over rendering-side.

* Thorsten