Hi all I am looking to try and generate an output which will always have the same co-ordinates. I am try to do this as we have a rapidly expanding cave system which we would like to plot on google earth (or the likes) using Bill Chadwicks map of the Mendips http://www.bdcc.co.uk/mendip.html Now after consulting with Bill it appears if we predifine the size of the plot the crunching, just becomes computer power, so we can update then map as data comes in, full instructions are at http://www.bdcc.co.uk/GoogleCrunch/Crunch.htm Any hints welcome, one idea I have had is to use a 'blank' bit map as a surface, does it always displace the whole surface? This is something that I am having dificulty understanding the instructions for thanks Andrew PS as soon as we fix the corners we will go back to the old fashiones paper problem of going off the sides....