Creating Environment Maps for FS2004

Microsoft's Flight Simulator makes use of environment maps to give aircraft the appearance of reflective skin surfaces. Creating an environment map with different qualities can give the skin of an aircraft quite a variety of changes in appearance.

Note: Before editing any files in your Flight Simulator installation, make a backup copy first!

First up is getting an image that's suitable for use as an environment map. The image must be cropped into a square, which has the vanishing point of the horizon about 50% down the height of the image. The default MS envmap.bmp is a 256x256 resolution file with mipmaps, so this is what I'll work with for this article.

Here's a shot of DTXbmp, available for download here, where I'm saving a digital photo I've cropped to the proper size using Photoshop. I'm saving in extended .bmp format, DTX1 settings, and including mipmaps.


Below are shots of both the envmap image I used, as well as how it looks in FS2004. Clearly visible in the screenshot, the environment map shows detail, perhaps too much detail for an aircraft that isn't well polished.


To solve this, I took my original cropped digital photo into Photoshop, and used the Gaussian Blur filter on it, and repeated the save process in DTXbmp. This gives the results shown below. The environment map now has more subtle details, an improvement I think.


I want to take this a step farther, so I return to Photoshop, and add some additional Gaussion Blur filter, and also desaturate the green in the lower part of the image, being careful to keep the blues on the horizon area, and resave with DTXbmp. Back in FS2004, now the 727 seems a bit less polished, but still you can see some terrain forms below, and a nice horizon line.


Using these same ideas, it's possible to create a wide variety of environment reflections. However, there are some limitations. Firstly, the environment maps cannot change with the scenery, so flying over water or desert will still show the same reflection. Secondly, it appears that all aircraft in FS2004 share the same environment map, instead of individually.

Overall, given the flexibility shown here, it's worth looking at the environment map to get a more realistic appearance for a new repaint project with lots of bare metal. Below is another environment map I created, with very subtle colors and detail.