Airphoto homepage 

• Airphoto homepage created..
  October 27, 1997

Airphoto is a tool for importing aerial and satellite photographs into the Flight Simulator ("MSFS") scenery. It also allows converting bitmap files into MSFS textures, generating MSFS palette and haze files optimized for displaying a particular bitmap, and generating a corresponding haze file for any MSFS palette file. Airphoto is suitable both for novice users and for experienced scenery designers.

This section lists bugs in Airphoto v1.1 and possible workarounds.

"Unresolved label" error messages when trying to compile a file produced by Airphoto

This problem only appears if the dimensions of the source bitmap do not exceed 256x256 pixels. It is caused by a bug related to reduced resolution textures. When Airphoto encounters such a small bitmap, the support for reduced resolution textures is disabled in order to generate a smaller BGL file. Unfortunately, it is not disabled everywhere.

Workaround:

Use the /NOREDUCE or /NR switch when converting small bitmaps.

The bug will be fixed in the next version of Airphoto.

"Floating point error: Stack fault" error messages when trying to start Airphoto

This problem can appear when using incorrect syntax for coordinates in /POS or /PPOS switches. For example,

/pos n1 w1 n1m01 w1m01 20

would result in a stack fault because 'm' is used instead of 'd' in 'n1m01'.

The bug seems to be caused by 16-bit C libraries. It will disappear with the next version of Airphoto due to porting to 32 bits.

"Flashing" of textures in scenery files generated by Airphoto

This problem happens with sceneries created from large bitmaps using reduced-resolution textures. It is caused by the way MSFS handles texture-mapping instructions. The first time the scenery requires a certain texture to be applied to a polygon, the texture name is placed into a 'queue' and the polygon is drawn using a solid color. For each frame, MSFS loads only _one_ texture from the queue; this is why some polygons may appear in solid color for a second or two if multiple textures have to be loaded at once.

As the aircraft moves above the scenery, the distance between the viewpoint and individual 256x256-pixel textures changes, thus causing different textures to appear at full and reduced resolution. When a set of textures is reloaded for display at a different resolution, "flashing" occurs.

Possible workarounds:

• If you are familiar with SCASM or FSASM, you can try to change the color of "flashing" in order to minimize the disturbing effect. Edit the SCASM/FSASM file produced by Airphoto and find the first RefPoint instruction. Insert a SurfaceColor( xx F0 ) [FSASM: SurfaceColor xx] instruction before RefPoint. Specify the desired color instead of 'xx'. "Flashing" will not be eliminated but could become less disturbing.
• Do not use reduced resolution textures. I do not recommend this, because in my opinion, "flashing" is less evil than enormous RAM requirements and the "boiling horizon" effect which would appear without reduced resolution.

It is impossible to completely eliminate "flashing" without significant sacrifices in the frame rate. The next version of Airphoto will introduce a "randomizer" which should reduce the flashing effect. I am also looking for other solutions.

Other bugs...

are unknown to me and should be reported. I cannot fix bugs if no one complains about them. Please always report the following:

• The version of Airphoto you are using.
• The version of Flight Simulator you are using.
• The scenery assembler you are using and it's version.
• Exact spelling of the command line you used to start Airphoto.
• Exact spelling of all messages displayed by Airphoto.
• The size of the source bitmap (pixels).
• Problem description.

It is illegal to redistribute Airphoto on commercial CD-ROMs and other commercial media without an explicit permission from the author, and it is illegal to use copies of Airphoto obtained from such illegal sources.

Following permissions for redistribution have been granted:

• On the CD-ROM published by Federation Nationale de Simulation, France.

Download aphoto11.zip (101k)

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