CompuServe Messages

Shucks. I guess it's what you mean by 'accurate'. My 3d terrain files only end up as visualization tools, we don't do volume takeoffs or sections, for example. It's just a fast way to get the general terrain in quickly. If and when more detail is required, or revisions are made, I manually edit the faces, and add things like curbs, cuts, and so on. As usual, part of the trick is to know how much detail is needed, and only work it up where it's required. Anyway, the level of accuracy is relative to the data I start with. These days, if we comission a survey, we require that we get the data as a 3D AutoCAD file, which puts much of the work on someone else's plate, and it usually arrives quite accurate. To carry this accuracy forward if required is a function of the Surftab variables that I set when hanging faces between the contour lines. Anyway, sounds like you have more precise needs in the terrain field than I do. I reserve my accuracy for the buildings we do, since that's our meat & potatoes. Anyway, talk to ya' later, Gary