Re: [Flightgear-devel] Implementing realistic radar inside the Flightgear engine

[Renk T. <tho...@jy...>]

> I have no idea  
> though about Nasal terrain sampling performance.

Pretty good these days - whenever a convective weather system is set up, we use about O(1000-2000) terrain elevation sampling points to generate the cloud-terrain interaction, they're done at a rate of 20 per frame. On my old computer, this is visible in the framerate indicator as a temporary reduction, on my new computer it doesn't even show. 

If you evaluate 1-5 rays per frame, you're certainy not causing massive performance drain.

> I know the advanced weather system uses a C++ random area terrain sampler
> written by Torsten Dreyer.

Yes - but the way this is currently set up it wouldn't help you - it just samples various averages and variances of the elevation, it can't be used to give you a profile of the terrain.

* Thorsten