Editing MESH with MicroDem

[Guest pecrowther]

I understand that MicroDem is the only ("best"?) freeware package to edit terrain points. I tried to do so, but am baffled (again!). I am using Microdem 7.01 alpha.1. I went to In/Out.2. On the "Data Manipulation" Screen, I went to "Edit Dem".3. This loaded my file and an empty table.4. I outlined the area of interest, which populated the table.5. I edited values in the table.6. However, when I saved the data, it did not save my file, as edited. It saved a small file. This small file is not recognized as a dem by other programs.How do I save my whole dem file as edited?Is there a good online tutorial on using MicroDem with FS2xxx?Thanks,Phil

[Guest sgreenwood]

Hi Phil,To save the Edited version, be sure the Edit window is selected. The File menu should then offer only one option: Save DEMThis should save the entire modified version.I don't know of any good resource for learning how to use the program. The MicroDem Forum can be helpful, and a search with Google will list a few related sites, but I haven't found any that were very helpful.Posting questions in this forum is probably as good an approach as any.Stevewww.fs-traveler.com

[Guest pecrowther]

Steve,Thanks. You were right. It was a dem, unreadable by my other dem viewers. But I was able to convert it to a bsq using mdem6bsq.Two things I learned:1. On microdem, you can't make changes directly to the table. You have to click on the number in the table and enter the number in the query form that pops up. Otherwise your "changes" will not be saved. Also, watch out for the query form presenting you with a number with a leading decimal point.2. On mdems6bsq, if you have a 10m dem you have to enter .1 for the first mdem6bsq entry.I am trying to see if I can flatten the terrain enough to lay a runway directly on the terrain, without losing the natural upslope of the runway. Instead of a runway, I am using 3 side by side FSSC generated taxiways with lots of points."Mostly" successful, but there are a few spots where the underlying terrain peeks through.I used Coastline maker to lay a road underneath, but it is not the same color as the runway and shows through. Also the road has yellow edges.Phil

[Guest luissa]

Hello Phil,For 3 arc second SRTM files you can use this litle tool:http://www.ptsim.com/downloads/DEM2BSQ.ZIPto convert an HGT file to a special BSQ file format. I say special as it includes in the end of the BSQ file, its size, its location and its resolution. Once you convert the HGT to this "special BSQ", you can manipulate the BSQ in different ways: merge BSQs, crop a BSQ, view a BSQ, up sample or down sample (3 to 1 arc second or 1 to 3), low-pass filter, interpolate void values and convert to Bitmap and back to BSQ.When I want to to edit a mesh I convert the BSQ file to a bitmap file. Then, with Paint Shop Pro, I edit the green and red channels. Then I save it as a 32 bit bitmap, convert it to BSQ and view the result in the "BSQ Viewer".There is no help for the tool but may be it is useful. One thing that you need for editing altitudes is:Altitude = Green + Red * 256Regards, Luis

[Guest pecrowther]

Sorry I didn't notice your message until now.What tool do you use to edit BSQ?I tried manually editing the runway area with MicroDem. There is some improvement, but it could take a lifetime. I did notice that Microdem has a feature that allows you to eliminate a rectangle.One idea I had was to wipe out an area, find out the values at the corners and interpolate. This would create a flattened area that is on a slope and should be smooth enough to lay those runways (really taxiways) on top.Or perhaps the BGL editing tool will do all of those things?Thanks, as always,Phil