> We could also simulate the condense effect by this (when in right
> combination of temerature and rel. humidity, water drops appear behind
> the engine).

That would be nice.  In the interim I'll have the contrail level default to 
30000 feet, and make it user-settable in the startup configs.

> Texture for this puff should be a bit more transparent, but 
> should vary as well. 

The trouble with transparent puffs is that they change transparency when they 
overlap.  Textured might work out better.  Here's a nice reference photo:


> It should last for more than 4 seconds as well and 
> should slowly scale up (like the real condense lines when you look at
> them from the ground).

A 4-second trail looks like it has about 50 puffs in it (I'm guessing).  At 
some point there is a limit to how many AI objects you want at one time, but 
I don't know where that point is.  An 8 mile long contrail will take an 
airliner one minute to make, and that will require 750 puffs to build.
I think we'll need a different system to build long contrails.

As for the scaling, I don't know if that's possible.  Does Plib support 
scaling an object over time?

David Culp

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