Hi,I have a small problem, I am trying to create LWMPoly3's. While investigating the geometry, I extracted a typical LWMPoly3 from an HP* file and got the following:You will see that the minimum x and y values are 1 and the maximum 255. Am I correct in thinking the x=0/y=0 are never used?Any help would be appreciated,George

Hi George.It was found some time ago that zero is treated as one for LWM polys. I think this allows an overlap of one pixel, so there isn't a gap due to mipping or view angle.You can code 0, and the sim shows it just fine.Dick

Thanks Dick,You are a fount of knowledge. You gave me the basis of what I am trying to do with your lat/long conversions.I am now ready for some serious programming. It's amazing what problems there are in a simple excercise of decomposing a closed polygon into separate areas. Well, I am retiring from work at the end of next week to I should have plenty of time.George