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have flown Flight Simulator for longer than I care to remember, right
from the early days in the 1980s, when wire frame aircraft were all there
was and scenery of any description was beyond our wildest dreams. Because
of this I still marvel slightly at the Microsoft default scenery in
FS2000, although I guess I must be getting used to it these days, because
when Eddie Denney started to release his series of US mesh sceneries I
began to download them out of curiosity, state by state. Before long a
combination of the new scenery and Fred Banting's recently released
DHC-2
meant that I was up late every night canyon flying - by the time Eddie had
released the first half dozen files I was completely hooked.
The reason I was so interested in Eddie's scenery to begin with is because
it is based on the public domain United States Geological Survey data,
which provides accurate elevation data for the Earth's entire surface. The
USGS data is important because the FS2000 default scenery uses a far
simpler scenery model than the simulator engine is actually capable of
displaying, and this will be familiar to anyone who has explored the
FS2000 world to any extent. One problem is that some areas have had more
attention than others: the Montana scenery, for example, is unbelievably
inaccurate, missing out entire ranges of hills, while Alaska is relatively
detailed.
The other problem is that the polygonal default scenery in FS2000 inevitably results in repetitive shapes, particularly in mountainous areas, where every ridge tends to look the same, with the result that VFR navigation is far less interesting than it should be. Eddie's files transform flying in the US, because with his scenery installed terrain elevation is completely accurate and someone who is familiar with real VFR flying should be able to navigate with confidence in Flight Simulator. This is not to say that the terrain is completely accurate after installing the mesh scenery; a couple of problems remain, due to the limitations of FS2000's placement of items such as water and roads, but if I say the Grand Canyon gives me an almost irresistible urge to download an F16 and fly down the valley flat out, you will get the idea how good it is. The one problem users are likely to face with installing this package, apart from the total 190 Mb download, is that Eddie gives very concise installation data, which means that you need to be reasonably confident handling FS2000 sceneries to install it.
The man we have to thank for this is an AH-64A Apache Technical Inspector
for the U.S. Army, stationed in Korea, and he has done the entire project
in his spare time, downloading the USGS data files which contain elevation
data for the entire world, re-organizing them and running the output
through the recently released Microsoft terrain software development kit.
Although Eddie shrugs off the complexity of the task, there is no doubt
that it is one of the most ambitious projects ever undertaken for Flight
Simulator by a single individual. The fact that this fantastic US terrain
is available as freeware is enough to raise him, in my eyes at least, to
an automatic place in the Flight Simulator hall of fame. Eddie's scenery
is incredibly important not only because it is the first accurate mesh
scenery to cover the United States, but also because it is freeware. I
have no doubt that we will see commercial releases of mesh scenery for the
US (and hopefully elsewhere - anyone fancy doing Europe?) before very
long, but these will be the product of professional teams or programmers,
and they will cost.
I asked Eddie what inspired him to take on the heroic task of tackling the entire continental United States, 'I guess the thing that got me started was the fact that the first scenery I tried to make with the SDK worked, and it looked so good I had to keep going and share it with everyone,' Eddie replied. 'After I did the area around my home town in Alabama and moved up to the Smokie Mountains area I knew this would be something everyone would want as an add-on. That is when I released the Southeastern Mountain Scenery (Atlanta West). Then I decided to do Colorado since I had spent a few years there and knew some of the landmarks. I had to see what they would look like on the sim.'
One of the disadvantages of highly detailed scenery is that it hammers
frame rates, particularly on lower specified machines. I ran the scenery
on a 733 MHz Pentium with the terrain texture detail distance down to 24
miles and in the canyons I was pulling frame rates of 20 or less with
clear skies, compared to 60 or more with the default scenery. My
conclusion from experiments on a couple of other machines is that it is
debatable whether it is worth running the scenery on less than a 450 MHz
Pentium, and on my 300 MHz machine the spot plane view of the Beaver in
the canyon failed to paint the aircraft textures, things got that slow.
One way to get increased frame rates is to turn terrain detail down within
Flight Simulator, but this defeats the whole object of the loading
detailed scenery in the first place. If you do have a machine fast enough
to run it, apart from few areas which suffer from inexplicable choppiness,
despite fairly high frame rates, in general the scenery runs like a watch.
This isn't surprising given the amount of time that Eddie has devoted to
making things run smoothly, and he told me, 'I think the biggest obstacle
has been working to find a way to stop some of the system pauses and
increase frame rates. My first three releases were made with the Level of
Detail (LOD) on auto, which after some experimentation I found to be LOD
9, and this resolution was causing very poor frame rates and long system
pauses. I then started using LOD 8 and this helped a lot. That is when I
decided to redo Colorado and the Grand Canyon, and then released Version 2
of these sceneries.'
The new US scenery and FS2000 are not a perfect match. The most obvious
problem is the placement of rivers. This is pretty bad
in the default setup, but Eddie's mesh scenery is so good that it is often
possible to spot where rivers should be, but almost always are not - you
have to get used to rivers defying gravity half-way up the side of
mountains and the occasional eye-catching flying lake. Another problem is
that some airports are at the incorrect elevation in Flight Simulator and
so a percentage either sit on small hills, or are recessed into the
ground. If your favorite field is affected the solution is to slew a plane
to all four corners of it and work out a custom exclude file. Given the
number of airports affected, this is likely to deter many causal users who
just want to fly and aren't interested in hacking the scenery.cfg file.
The USGS data files are mind-bogglingly complex, and to give an idea of the trouble to which Eddie has gone, it is worth hearing him out on the data handling problems he faced, 'The hardest scenery area I have done is the Alaska scenery. The lower 48 DEM files are pretty easy to arrange since the USGS has a map to select the areas from. But the Alaska DEM's are listed in alphabetical order, and therefore all out of order. As I converted each file I had to get the coordinates of each one and then arrange them so that I could put them order to finish processing them.' And we should all be thankful that he did, because in many ways Alaska is the most interesting scenery in the entire package.
So what next? As I said earlier, my greatest hope is that Eddie will turn
his attention to Europe next, so I asked him what his thoughts were. 'I am
planning on releasing a CD version of the scenery soon, if all goes as
planned, and I plan to put some high resolution areas on the CD also. I
will have to see how this goes, as I have about one and a half months left
here in Korea until I head back to the wife in Georgia. I will definitely
have to slow down for a while when I get home, or the wife might kill me.
I am presently working on the Columbia River Gorge and Yosemite National
Park, each with 30 meter resolution. It is amazing how much detail shows
at this resolution.'
The Microsoft Terrain SDK, coupled with the USGS data, heralds a new era for flight simulation. Take a look at the 'before and after' shots (FS2000 default scenery is always at the top) and you will appreciate that there is little doubt that the days when users would tolerate polygonal hills scattered on a flat plain are gone.
The next release of Flight Simulator, as well as any commercial scenery
currently in the pipeline, will have to use mesh data or face relegation
to the second division. On this basis, Microsoft will do well to look
carefully at rivers and lakes, as not only does their shape and location
lack accuracy in the current version, but the lifelike appearance of mesh
scenery highlights the need for a better visual appearance. As the icing
on the cake, I'm looking forward to the release of Lennart Arvidsson's
new textures
which should appear in beta form in late August; couple these with Eddie's
scenery and Flight Simulator takes a step closer to reality. But right
now, I'm looking for an F16. Anyone want a ride?
Likes:
Dislikes:
Andrew Herd
Download
Eddie Denney's terrain mesh scenery
andrew.herd@btinternet.com
| Frame Rates -- Eddie Denney's US Mesh Scenery | ||||
|---|---|---|---|---|
| These frame rates were calculated in six standard situations | ||||
| 733 System | 300 System | |||
| Mesh | Default | Mesh | Default | |
| Montana canyon | 20 | 62 | <10 | 30 |
| Montana canyon - spot plane | 20 | 55 | NP | 26 |
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Both machines running Windows 98 second edition, FS2000 Professional
Edition, update 2b applied.
Specs: 300: Intel Pentium 300 MHz, 128 meg RAM, Voodoo 3000 16 Mb RAM.
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