oceanheightfield.bmp water effect question

[Magneto]

I'm wondering if someone can advise me.
I've been trying to experiment with water textures, etc.., and I'm having a problem with the oceanheight bmp file.
The original size and format is 512x512, 8-bit, indexed color, uncompressed with a file size of 342k.  Both Photoshop 5.5 and Corel Photopaint show this file as a normal 8-bit BMP, and they show no special "masking" or alpha channel.
I've used Photoshop 5.5 to convert a rework of mine to (what should be) the same size and color mode, but my file size comes out to 257 kb.  
Ok.. something is wrong here. File sizes should match if they are the same dimensional size and format.
When I install my 257kb file into FS9, the sim crashes at scenery load with water effects set to high.  Works just fine with the original 342kb file.
So I then tried installing a 24 bit color version (768kb) into FS, and the sim will load, but I have no water effects. Ok. so that isn't working.

Any ideas what I need to do to get my file correctly formatted to FS9?  DXTbmp shows the file as a "normal" bitmap, but I guess there's something else that I'm missing.

Your help is seriously appreciated.. Thanks. Mag...

[garymbuska]

I have read here somewhere that alot of the BMP files use extended textures and the programs that you are using will not support that and is porbably chopping of parts of the file. There was mention of a program that could be used that would allow you edit those files in that format but for the life of me I can not rember what it was.
I am not sure if the oceanheight.bmp file is one of these files but from what you are saying it sounds like it might be. That would explain the file size differance.But I could be out in left field here.

[Magneto]

I have read here somewhere that alot of the BMP files use extended textures and the programs that you are using will not support that and is porbably chopping of parts of the file. There was mention of a program that could be used that would allow you edit those files in that format but for the life of me I can not rember what it was.
I am not sure if the oceanheight.bmp file is one of these files but from what you are saying it sounds like it might be. That would explain the file size differance.But I could be out in left field here.

Thank you very much for the reply.  If you happen to remember which program that was used to edit those types of files, I would be extremely grateful.  I'm not even sure exactly how the alpha info is stored in a bitmap, but it does appear to be there.  I was able to get a "targa" of the file with the alpha on it, but was unable to convert this back to the proper bmp format that FS needs.
Not much info around the web on this.  I was hoping some of the designers might help me out a bit.  

Mag...

[garymbuska]

try searching for a extended bitmap editor using your favorite search engine .You might get lucky The program I saw might have been for FS2002 and that would be of no use to you. Since fs2004 uses a diferent approach.

[RollerBall]

[quote]

[Magneto]

Rollerball,

 Thank you for the in-depth reply. I appreciate the help.
I have found the answer to my problem, and it wasn't an alpha channel problem like I thought it might be.

The oceanheightfield.bmp shows as an 8-bit indexed(or grayscale) bmp, but it contains mips.
After downloading Microsoft's TerrainSDK , and getting the ImageTool.exe utility, I was easily able to add the missing mips and save the file in the proper format and size. It works correctly now.

Another thing I wanted to touch on is way DXTbmp won't load a normal bmp as an "extended" one.  It also would not convert my 24 bit version to an 8-bit one. I'm not even sure if it matters if the file is 8-bit or 24, but the mips are essential.

So now I can do some experimenting..  Thanks for all the help.   I needed ideas, and you people helped.

Mag...