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Hi I have a very detailed image 4000 x 9000 aprox /about 39 pixels per centimetre Can Terrabuilder work with this file odd file dimmension the detail is extreem as you can see a sample piece on my sitehttp://nzcoaster.kiwiclub.com/mesh.htmI give terrabuilder the right coordinates and it comes out at a scale like 0.5 metres per pixel which does'nt seem to produce anything when processedI then change the settings to say 2metres per pixel and lock it there and I get this image that displayes well in the sim but it is like 27 kilometres long by 10 kilometres wide,and I know for a fact the area involved is only about 2.5 km wide and around 5km long aprox valuesReally any help would be appreciated and also is there a tool for calculating pixels to metres I recall some calculater or converter that was mentioned some time ago for calculating image dimensions for terrabuilderMuch ThanksGreg

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Greg, terrabuilder is a front end feeding resample.exe, which only can process an image into terrain at LOD 13, which corresponds to 4.8m/pixel. If you convert your image to 4.8m/pixel, you should see what the image will look like in terrabuilder. The reason the extent of the area is wrong with what you're doing now, is that you imagine the resolution to be very high, but resample.exe doesn't care, it locks your resolution at 4.8m/pixel.Bob B

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Thanks Bob for your replyIs there a formula for this conversion and does the image have to be squareThanks Greg

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the image can be any rectangular dimension. That doesn't mean the entire image will be displayed. Resample.exe will ignore any LOD13 grid areas that are not completely filled with image. Its pretty easy to define the extents of grid squares in your area, I made an excel spreadsheet that calculates the nearest lod borders from any point in the world. write me at bob@"Removethis"blarg.net, and I'll send it to you.Image resolution is a pretty simple matter. My favorite way to explain it is to start with realizing that the objects in your image have a fixed dimension. If you have a runway, its even easier, cuz its normally easy to find an accurate length for the runway.I take the known length in meters and compare it to the measured number of pixels from my image. That's resolution in m/pixel. Say I do that and get 2m/pixel. Now to resample the image and result in 4.8m/pixel, I now let the pixel count be unknown in the same equation, and determine the needed pixel count for that resolution.for example: let X equal the length of a known object in meters, let P equal the number of pixels needed to display that feature and let R equal the image resolutionX/P=R, determines the starting resolutionto determine the pixels that would be needed to see the image at a different resolution, set R = to the new desired resolution, 4.8m/pixel in this case, and solve for P (the runway ain't gettin longer or shorter in the near future, so X is constant!)so, P = RXNow we know the pixels we started with for the feature, P(0), and the pixels we want to end up with for that feature, P(1), devide them and you know the amount you need to modify the overall image.Say, P(0) = 155 pixels, and P(1) = 95 pixels, you need to be shrinking your image by 155/95, or 1.63. Now if your orignal (2m/pixel)image is say 3000 x 4000 pixels, you devide those numbers by 1.63 as your goal for the final image size after resampling in a graphics program. The final (4.8m/pixel)image in my silly example would be 1839x2452 pixels NOTE: to drive you nuts Microsoft used the word resample in their terrain tool resample.exe. Resample is a standard word that means to change the pixel count used to display the same information. Resample.exe does do resampling, but it does a bad job of it. I'd suggest you modify your image in a graphics program designed to the job. Elrond Elvish has produced a kick butt stand along program for this, give it the # of pixels you want the image to be and let it do its thing.Note 2, basing the resolution on the overall image to a measurement made on a small part of the image will amplify error. This has NEVER been a problem for me, but I do try to use the biggest object that I know the length of when using this method.Bob Bernstein

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