CompuServe Messages

>>Eric, You might also consider 3dSurf (Ipas) and QuickSurf (AutoCAD) by Schreiber Instruments. My choice is Quicksurf, which is a full featured terrain modelling software. The nice feature for 3DS is the fact that the surface faces can be isolated for material application in 3DS. You can also use the large bitmap approach for mapping the surface as well (see the VAIL.3DS model on the R3 CD). Quicksurf can also read DEM files directly from USGS. This will give you the capability to import high resolution models and refine the data to the level of detail that is necessary for your project. Hope this helps, CT.<< Actually it was Chris Thomas who talked about Quicksurf and all that, as you can see above. Here we use and Autocad plug-in called Landcadd. There is a small program we purchased from a company in Colorado that converts DEM information into points, dxf, or faces. We use that information to create the landscape meshes in Landcadd. The progrmam (called DEMDXF.EXE) would work for your program as well, assuming it can accept ascii xyz files (most terrain generators do). Most likely Quicksurf uses the DEMDXF.exe program since the people who wrote it have a fairly close working relationship with Schrieber Insturments. I have never used Easysurf, so I can't comment on how it works, and have only glanced at quicksurf. The 1-degree DEM info is mostly useless since the spacing between points is something like 100 meters. The 30 meters stuff is much more usable. There is also the matter of projection. DEM files are generated in the UTM projection, and if you plan to use any other type of digital data (TIGER or DLG files, for example) you need to make sure they are in the same projection. This may not be a problem for you, but it is something to be aware of. This is something we have to deal with all the time. I believe 3dsurf has a 65,000 face limit, which you can run into very quickly if doing any type of large mesh. The files can get very large, face wise. For this reason I would not recommend purchasing it, you would be hitting the limit far too often. If you are wondering how we convert the dem data into a useable file, here are the steps I generally take to get to a finished mesh. 1) convert the DEM file into and xyz ascii file (using DEMDXF.EXE) 2) convert the xyz file to the proper projection (if necessary, that is. We have several programs that can do this) 3) use Landcadd (or whatever terrain generation program you have) to read in the xyz file and triangulate the points and create a mesh based on the cell size we have entered into the program (ex: square faces that are 150 feet to a side). Since landcadd is an Autocad program, I then have to export it to dxf then that to 3ds. Since 3ds has a 65,000 face limit, I have to break it into pieces to import it. Most meshes I generate have between 200,000 and 300,000 faces. The Optimize routine on the IPAS boutique disk #7 (I think) has been real handy. forgive me if you already knew some of this. I wasn't sure exactly what you wanted me to comment on further, so I tried to touch everything. Let me know if you hav any more questions.