[Flightgear-devel] FlightGear terrain engine

[Christian B. <chr...@gm...>]

Hello everyone,

my name is Christian Buchner. I am responsible for the notoriously
troublesome "Tileproxy" addon for
FSX and FS 2004. I have recently had a look at FlightGear - I compiled it on
Windows XP and I am quite
determined to do some hacking on the terrain engine.

I would like to get a few pointers where to look for information about the
terrain engine that is currently used by
Flight Gear. In particular about the irregular terrain mesh - how is it
created (at runtime or offline) and how does
photo texture currently get mapped onto terrain - how are roads and other
terrain features added? (is it all
vector or is it texture maps)

Some things that I would be interested in working on are:
- dynamic terrain tesselation, dynamic LOD
- terrain self shadowing (shadow maps)
- offloading some of the above to other CPU cores
- shaders for water surfaces
- mapping phototerrain dynamically (potentially reusing some Tileproxy code)
- more shaders for atmospheric effects

OpenGL and OpenScene Graph are quite new to me, before I've done some basic
DirectX and some
basic shaders (up to Shader model 1.4) So it will be a steep learning curve
for me.

First I need to learn about the capabilities and limitations of the existing
terrain engine. So any
resources you can point me to would be appreciated.

I would like to point some eyeballs towards an interesting technique that
was employed in the following
work published 2 years ago: They use z displacement mapping with Vertex
Shader 3.0 to get some
astounding detail at high FPS. Now map phototerrain on top of that and you
have a winner ;-)

http://www.diva-portal.org/diva/getDocument?urn_nbn_se_liu_diva-5623-1__fulltext.pdf

(try to ignore the military aspect of this work - the technology iused s
quite interesting)

Christian