New Landscapes for Eagle Lander 3D

By Al Cikas

Eagle Lander 3D is a realistic flight simulator for the Apollo Lunar Module’s final approach to the Moon’s surface. The program presently comes equipped to simulate four of the six Apollo landing sites, only Apollo’s 14 and 16 are excluded. Having mastered the program to well over 500 simulated landings, the author began to look for new ways to make the program more interesting. Here are some suggestions other Eagle Lander 3D fans might like to try.

Each landing site consists of three photo-maps, named for their relative size; Large, Medium, and Small. Each of these designations is broken down into a Texture map and a Height map. For program purposes, these images are reversed from normal; bottom becomes top and likewise. In the Apollo 11 simulation, for example, the Small area represents roughly 1500 ft by 1500 ft of lunar real estate. West Crater dominates the area as the Lunar Module approaches, with a boulder field off to the right (North). The actual landing site lies beyond West Crater. It doesn’t take very many landings in the Apollo 11 or 12 sites before the newness wears off and the flat terrain becomes boring.

By incorporating a few new photographs from the Ranger and Lunar Orbiter missions, the author was able to create entirely new landscapes for Eagle Lander 3D, with some very surprising results. Simply changing the Texture maps, though, was not enough. The Height maps were what gave the terrain its vertical features, and some minor tinkering with the Height maps brought new and interesting possibilities to the program. The most basic way to change the landing area is to simply rotate the Texture and Height maps by 90 or 180 degrees. A more interesting approach is to "borrow" a map from one of the other missions. Finally, a little cut-and-paste from several height maps will generate entirely new terrains, difficult enough to become lost in. Also, re-sizing the West Crater Height profile will allow larger or smaller craters from other photographs to assume their own vertical profiles. The following examples use some of the basic images from Ranger and Lunar Orbiter to generate entirely new Lunar landscapes.

Most of the experimentation shown here was done on the Apollo 11 mission folder as it will be easily recognized by all owners of Eagle Lander 3D. The first thing to do is to copy all six Height and Texture maps (originals) over to a safe place on your hard disk. That way you can restore your program back to the original configuration after you are through experimenting. You’ll also want to set up an intermediate file folder for working with your new landscapes. In that folder, for example, you may want to make a copy of say the Apollo 12 Medium Height map, then rename it SmallHeight for experimental purposes. In all cases, you’ll want to experiment AWAY from the original game program files. In contrast, you’ll soon find out how easily the program is to modify, by planting new images within it, using the original image names. Until you become more proficient in transplanting these images, it would be best to simply tinker with the Apollo 11 Small images ONLY. Don’t worry, you won’t be there very long.

The first few ideas the author tried involved a couple of "A" and "B" Camera pictures from Ranger’s 7 and 8, which were in turn named SmallTexture. The Ranger camera grid marks were left as is at first, mostly to demonstrate the concept. It soon became apparent that these "plus" marks could be useful in learning to fly to a particular target area. These plus marks provide pinpoint targets. The program will allow you to land on them providing the Height information remains reasonable. (Later we’ll see what happens when it doesn’t.)

The first photos show the process in general.

Height Maps

These are the actual versions used in the Apollo landing site scenario, and the ones you’ll want to preserve. (Click on each image for a full-sized image) Most lunar images have to be scanned this large, or they will distort if enlarged. The Ranger images used had been scanned at 1100 by 1100 pixels, so no appreciable detail was lost as they were enlarged. Note how "West Crater" stands out in the Small versions (top, the Medium versions are below). By moving these around, and by using the cut-and-paste, technique, new scenarios are readily available.
Ranger photo
Note the dramatic effects of the new Height maps, and that the "plus" marks tend to follow the lay of the land. By aligning these images with features from the Height maps, a close proximity of the new areas could be generated. These Height maps have a waxed-paper look to them and do not seem to contain a lot of obvious detail. Also note the Apollo 11 boulder field has remained, while "West Crater" has been replaced. This will be a constant theme from now on.

Yet another Ranger picture demonstrates the ability to land on the plus marks.

Ranger photo

Note the height map for Apollo 11 has been simply flipped 180 degrees, putting a variation on "West Crater" off in the distance. A little more experimentation with another Ranger image generated a new landscape from the Height images, creating a lava flow across the crater which spilled over the rim and into the crater. Hiking this lava flow made for some spectacular images.
Ranger photo

Even more cut-and-paste with multiple Height images brought about a more unusual scenario
Ranger photo

Bear in mind, the goal was new landscapes, not technical perfection.

Somewhat more experimentation with a typical Lunar Orbiter image was augmented by borrowing Height maps from the Apollo 12 and Apollo 15 missions, particularly the Apollo 15 Rille maps. Here a smaller rille is actually walkable, and some nice screen shots resulted.

Lunar Orbiter photo
Lunar Orbiter photo
Lunar Orbiter photo

The main point in these images is to demonstrate the tell-tale "striplet" lines throughout the scenery which have replaced the Ranger "plus marks". For all these modifications, the Lunar Module’s landing radar works better than 90 per cent of the time, with very few last-minute, unexpected crashes. You do crash, though.

With all of these features forged into the program, it was time to set sights on two particular lunar features, Alphonsus and Tycho. By this time the SmallHeight and SmallTexture maps had undergone many exchanges. For Alphonsus, the "grid" or "tick" marks were completely removed using Photosuite’s bitmap features.

Alphonsus photo

This gave a more natural look to the new landscape. "West Crater’s" Height map was also modified and enlarged, and a shrunken version was added for the smaller near-by crater. The 65 mile wide Alphonsus was now down to 1500 ft square in the early versions,
Alphonsus photo

but the landing radar worked well and the terrain became so rough as to actually be able to lose track of where the Lunar Module was during EVA, even though the area was only 1500 feet on a side. The last image, an EVA screen grab, gives an idea of the difficulty level that can be stitched into the program.
Alphonsus photo

Later on, the Alphonsus area was adjusted to both the Medium and Large ranges, but with considerable loss of definition.

From Alphonsus, it was on to Tycho, using another Lunar Orbiter Image which had also been bitmapped in Photosuite to clean out the bright spots.

Tycho photo

Once again the "West Crater" Height map was modified with enough cut-and-paste to suffice. Originally, Tycho was also reduced to the 1500 ft. limit,
Tycho photo

but later it was moved to the larger area.
Tycho photo

A loss of definition similar to Alphonsus was experienced with the Tycho pictures. Landing on the edge of Tycho was a treat
Tycho photo

Similar but less-impressive landings had taken place at Alphonsus as well.

Sometimes all did not go smoothly. In many cases, improper cut-and-paste brought about some unexpected and bizarre scenarios. The first of these demonstrates how rocks and boulders can become suspended well above the surface level (if it weren’t the moon, we could call it mid-air).

Strange Height

It is often possible to walk under rocks and boulders, even under craters if the height information doesn’t agree. Often this confuses the landing radar and usually you will crash unexpectedly. In some cases, you simply come down too hard and the landing legs snap off.
Strange Effects

The author thought he was imagining things the first time this happened, there then came a landing where the broken footpad was wedged in the doorway. No doubts after that one; this program has some very sophisticated hidden traits. One puzzling effect was that when Apollo 12 was modified, the Surveyor dropped out of the simulation, thus a very desirable modification failed to materialize.

Finally, it was time for a bit of fun. The most facetious prospect of all was to determine if the Lunar Module could land on a Sunday comic character, the winner was Opus; a landing on his belly worked on the very first try. The biggest surprise was the color retention, after viewing so many gray-scale landscapes.


First Landing on OPUS ! Now if only the program would handle MIDI music!


Posted 6/16/2007