Take Flight with Fly! II

When people talk about flight simulators for Macs, they mostly talk about X-Plane, but there was another somewhat overlooked flight sim for PowerPCs called Fly! by Terminal Reality. Actually that was the name of the first incarnation, but the sequel which we'll mostly focus on here was called Fly! II and ran on both OS 9 and X. I had the original Fly!, but when Fly! II came out I didn't give it much thought as it was met by a bunch of negative reviews for being incomplete and rushed. The distributors apparently thought it was more important to compete with a new Microsoft Flight Simulator release at the time than it was to put out a finished product.

Fast forward a few years and I see Fly! II is abandonware on Macintosh Garden, so I decided to check it out. While the interface was less polished than the original Fly!, it offered better graphics and made for a potentially better development platform for creating custom scenery and additional aircraft--if you could get the editing functions to work. And this illustrated one of the biggest problems with Fly! II. It was buggy, and on Macs the built-in editor didn't work. It turns out there were several patches released, coalescing into one grand final patch, but the Mac version of it seemed to have completely disappeared from the web. It was supposedly available at the AVSIM Library, but they had a hacker attack a few years ago and didn't keep backups, so they suffered massive data loss including the Mac patch.

So we were kind of stuck. But then, just recently, a random good samaritan uploaded the final Mac patch to Macintosh Garden and rescued us from our doldrums. I ran the patch, and suddenly the editor works. I can import elevation meshes without it crashing, 3 arc second elevations that address one of my biggest problems with Fly! II graphically.

When you first run Fly! II, you get just the default scenery and elevations. The generic scenery isn't bad, but the elevations have so few data points it makes everything look like rolling hills. So I downloaded a bunch of 3 arc second elevation tiles from the USGS website (one data point every 90 meters), imported them into Fly! II, and what a difference it makes. Everything looks more realistic, and familiar geographic features look familiar again. Here's an example of Washington's Mt. Rainier with the default elevations and the enhanced (click to enlarge):

 So now with these new elevations, I can finally enjoy Fly! II with all its other advantages over X-Plane, including its superior plane and flight models and overall realism in flight procedures. The enhanced elevations I made cover the US West Coast (most of Washington and Oregon, all of California, and parts of Nevada), and if you want to download them I've made them available here. But all that would be kind of useless if you live somewhere else, so here's a quick tutorial on how to make your own elevations in Fly! II.

First, go to USGS's Earth Explorer website and choose the area you want on the map (click to enlarge):

Then click the "Data Sets" tab and expand "NASA LPDAAC Collections", then "NASA SRTM (SRTM3) Collections", where you can finally choose "NASA SRTM3 SRTMGL3". Click the "Results" button and you can download the files.

When you unzip them on your hard drive, you get a bunch of .hgt files that you must rename to a .ras extension. Now you can import them into Fly! II by launching the program and pressing Command - e to enter the editor. Under the scenery editor's Tools menu, select "Import Scenery...", then check "Generate Elevations", choose your DEM file to import, and fill in the necessary data. The example below is for the SRTM3 file N32W115.hgt which I renamed N32W115.ras (click to enlarge):

The first row latitude and longitude is for the lower left corner of the tile, and the second row is for the upper right corner (the longitudes go backwards when counting from west to east). The samples width and height are always 1201 x 1201 for single tiles. For "Subdivide Tolerance" the default is 500 feet, but I changed it to 200. Some people recommended going all the way down to 50, but you'll pay a price in framerates. For even better detail, change the "Maximum Density" from 4x4 to 8x8, though that may cost you a few frames per second, too. Experiment with what works best! Finally, click "Import" and let it do its thing.

When doing these one at a time, the results aren't perfect. Sometimes data from neighboring tiles gets overwritten and some blank spots will occur where it falls back to the default elevations. A better way is to combine the .hgt files into one big .ras file, but for that you need two Windows programs, 3DEM and 3DEMBin2Ras (available at the AVSIM Library), and either Virtual PC or an actual Windows computer. I have Virtual PC 4, and it worked but since Virtual PC 4 has a 512 MB memory ceiling, I was limited to combining only 6 x 6 squares. In any event, the process is simple. Open the multiple .hgt files in 3DEM, wait for it to render, then choose "Save Terrain Matrix" from the file menu. From the save options that pop up, choose "Binary Signed Integer. This will give you one big .BIN file which you then use 3DEMBin2Ras to make a minor endian conversion so the file can be imported into Fly! II. The resulting file will have a .RAS extension which you must rename to a lower case .ras. Apparently Fly! II only likes lower case extensions.

When importing a combined .ras file into Fly! II, the procedure's the same as a single tile, except the sample width and height will be some factor of 1200 plus one. For example, a 2 x 2 square (2 tiles across horizontally) will be 2 X 1200 + 1. So the sample width and height will be 2401 x 2401. For a 4 x 4 square, the width and height will be 4801 x 4801, and a 6 x 6 square will be 7201 x 7201. And for this I only tried perfect squares--I don't know if 3DEMBin2Ras conversions work on rectangles.

Finally, be mindful that you get the lower left and upper right corner coordinates correct on the combined files.

Online resources for Fly! II are starting to dry up. For a long time there was the site Fly.Simvol, but lately it's giving an "Internal Server Error." (looks like it's back up now) It's still accessible with the Internet Wayback Machine. Also, their downloads are still available at fichiers.simvol.org/fly/fly_2/ including some cool planes and France scenery add-ons, but I don't know how long that'll last so grab them while you can.

Another good resource is the AVSIM Library (free registration required). There you can find all kinds of user-created scenery add-ons and utilities, etc, of which I plucked many taxiways and airport sceneries. There's also a file library at FlightSim.com which has "Fly!II Blue Sky", a sky.ini replacement that looks much better than the stock sky, especially with water reflections turned off.

On the subject of performance tweaks, there are a couple of hand edits you can make to improve framerates. The simulator itself has several scenery sliders and sound options you can adjust, but beyond that you'll want to open fly.ini in Fly! II's "System" folder and change the "popBuildingsIntoView" value from 0 to 1, and "popBuildingsTolerance" to something like 8 or 10. These changes make 3D buildings pop into view only when you get close, and increasing the "popBuildingsTolerance" value decreases the distance at which they become visible.

Also, open render.ini in the same folder and you'll see about a dozen MaxTextures lines. I changed "maxTextures128" from 64 to 250 and got a modest boost in framerates, but more importantly the simulation became much smoother and less herky jerky. This has to do with the slots Fly! II allocates to your graphics card, and flying with the debug info turned on, I saw that there was a logjam with the 128 x 128 textures. You can read more about render.ini settings at the Fly.Simvol FAQ.

Your Mac's menubar will present somewhat of a complication. In the original Fly!, the space key could hide it, but in Fly! II it's always there in the way. To hide the menubar with the space key in Fly! II, you need to add the line "allowHiddenMenubar=1" to your fly.ini, and this will only work in Mac OS 9, not in OS X. And it's a bit glitchy when unhiding, which is probably why it's not there by default. Though OS X users can't hide the menubar, they can run the simulation in windowed mode to get the full 1024 x 768 resolution without the menubar blocking its portion of it. To do so, have "autoFullScreen" equal 0 in fly.ini.

Though it's getting long in the tooth, Fly! II is definitely still the best flight simulator for Macs running OS 9, and may even be the best for PowerPC Macs on OS X. Hardware requirements are somewhat different depending on which system you have. Framerates are better in OS 9, so there you may want a 733 MHz chip or higher with a decent graphics card. OS X users will need a higher end PowerPC. It runs reasonably well on my aluminum Powerbook, but I wouldn't want to use it on anything less.

One last note about the elevations I made, there's a hole in the Earth off the coast at San Simeon, CA, near where Hearst Castle is. This is due to that particular SRTM file having the ocean at an elevation of -9 meters, which the Fly! II editor interprets as a bottomless fathom. I suppose you can edit the data files to fix it, but I decided to leave it in as a monument to weirdness.

And since this post is approaching terrorist-manifesto-length, I think I'll sign off now.