Thanks Luis,Dick has just sent me his new version of TerrainCalc2004 which shows the current bmp and the other 8 surrounding it. It works beautifully.I was able to fly (taxi) around my lake in top-down view and it displayed all of the bmp's required. Now, armed with your alpha channel tutorial it should be easy to uncover the water.Thanks again for such fantastic support,George

Hi Luis.George and I have been in contact, and he has been helping me to squash bugs in TCalc2004. I hope to release this next week ( waiting for some other input, and some communication from flightdecksoftware.com ).The current version seems OK.http://webpages.charter.net/ludowr/TCalc2004_AyersRock_2.JPGhttp://webpages.charter.net/ludowr/AyersRock.JPGHere I have crushed a mesh-clinging smiley face with Ayer's Rock, and placed a nearby label as "19, 4". ( JR Morgan was my inspiration for this ). :-lolTrue elevation, true heading, terrain stuff, odd bitmap names, different lat-long formats, and gets info from the running sim.====================Here's the code for the nonsense at Ayer's Rock:include TDFMacros.incinclude TDFHeaders.inc; ===========================VTP2Custom Macro ZoneX, ZoneY, LayerNum, TextureID, AreaX, AreaY NWVtpX = ( AreaX * 255 ) + 4080 NWVtpY = ( AreaY * 255 ) + 4080 VTPDataArea 1, 1, ZoneX, ZoneY VTPLayer LayerNum, 0 VTPNumTexturesInLayer 1, 0 VTPTextureId TextureID, 0 VTPPolyCount 1, 0 VTPPolyMethod2 4, 0, 0 VTPPointXY2 NWVtpX, NWVtpY VTPPointXY2 NWVtpX + 255, NWVtpY VTPPointXY2 NWVtpX + 255, NWVtpY + 255 VTPPointXY2 NWVtpX, NWVtpY + 255; Usage = VTP2Custom ZoneX, ZoneY, Layer, TextureID, AreaY, AreaYEndM; ==========================; S25* 21.0443' E131* 2.7823'BGLHeader -24, -26, 132, 130, TerrainHeaderStart, VTPHeaderVTPHeader label word VTPFileHeader 256, VTPIndexStart, TextureStart, VTPEndVTPStart label word; ---------------------------------------------------------------------------------------------------------; Cell_663_328datamark_0 label wordVTP2Custom 23, 8, 4, 0, 18, 3VTP2Custom 23, 8, 4, 0, 19, 4datamark_1 label word; ---------------------------------------------------------------------------------------------------------Cell_663_328 EQU VTPCellID 0, 663, 328 VTPIndexStart label word VTPIndexHeader 1, VTPIndexData, VTPStart VTPIndexData label word VTPIndexEntry Cell_663_328, VTPStart, datamark_0, datamark_1; ---------------------------------------------------------------------------------------------------------TextureStart label word VTPTextureListHeader 1, TextureIndexStart, TextureDataStart,TextureDataEndTextureIndexStart label word VTPTextureListEntry TextureDataStart, texturemark_0, texturemark_1TextureDataStart label word texturemark_0 label word VTPTextureName "253" ; no seasons... use 252 for a seasonal set VTPTextureType 1, 0, 0, 4 texturemark_1 label wordTextureDataEnd label word; ---------------------------------------------------------------------------------------------------------VTPEnd label wordThis uses a new macro to place a VTP2 poly as texture ID "0" which can be made as "253" to use Custom textures. It will place them over whole LOD13 Areas.Dick

Hi Dick,I didn't understand a word of your code, but it has given me an incentive to do some more reading.Just an update on my progress, I have successfully converted one of the bmp's for my lake, just 9 more to go. I am using Lynn and Bill Lyons' water textures which don't really fit with the dark waters of the English Lake District, (well, I was warned by Luis), so I think I will revert to the default VFR water textures.Thanks again for all of your help,George