KDFW Sink-Hole Problem

[dkohl 0]

What is the default grid size for TerraScene? 8x8? Is 8x8 higher resolution than 4x4? This is all quite complex for me. I just use TerraScene and fly there. I never got into editing and all the other manual work around TerraScene that would probably be really good to understand, but which I never really got.-DK----David KohlFly! II v2.5.240Dell 8200 P4/1.8G, 1024MB RAM, Nvidia GF4 Ti4600 v41.09, WinXP Home Edition SP1.CH Pro Pedals and Yoke USB.

[Guest]

I believe the default elevation slicing is 4x4 with a 500 foot subdivide tolerance. That information is under the "Advanced" button below the "Slice with Fly" checkbox on the render window. I think that's right. I can't see it as I'm at work.I'll give a quick rundown of the divisions here. This is what I would like to put in a documant about this stuff....Each globe tile is divided into 4 quarter globe tiles. Those are what the g**.trn terrain files represent. Each quarter globe tile is divided into 64 super tiles. Each super tile contains 16 ground tiles. The ground tiles are numbered relating to the quarter globe tile, therefor the indices of the ground tiles run the range (0,0) to (63,63) to make up a grid of 64x64 ground tiles. Each of these ground tiles has 4 elevation points, one at each corner, but they are recorded in the .trn files related to the super tile. That means that each super tile contains 25 elevtation points (a 5x5 grid that represents the corners of the 4x4 grid of ground tiles). Now, within each of the ground tiles you can have high detail terrain data. This data further divides a ground tile (the smallest tile I've referenced so far) into a 2x2, 4x4, or 8x8 grid. To take the simplest case, if you slice 2x2 detail into a ground tile its elevation is now represented by 9 points instead of 4. There are three points on each edge (with the corners being shared of course) and one in the middle. 4x4 gives you 25 points, and 8x8 gives you 91 points. Som with the 8x8 high detail grid you can get the ground that is affected by the elevation data down to a pretty small area. I haven't calculated how small, though.Like I said, I'd like to put all this info together with lots of pictures. I just need to take the time to do it.Hope this helps some more,nick

[Guest Eagle]

David - I have been following this discussion and I have gone to KDFW.From your pictures it appears that you get that sinking feeling at runway 17L or 17C. I have taxied in that area but do not sink out of site. Am I in the right area? I would like to correct this, but can't find a problem.

[Guest]

Wayne, at least in that second pic he is between 35L and 35C. That makes sense because that is just east of the seam between the two globe tiles.nick

[dkohl 0]

Okay. I read your notes. I will try method one in a minute, but I was studying method 2 - manually synchronizing the points across the two globe tiles.I'm not sure what you meant by "change the elev data for point 8, 9, 10, 13.... etc.Here is a portion of the HDTL for 7,3 in D186152G11.TRN: -- super tile 7 3 ========== BEGIN OBJECT ========== -- dimension in tiles 4 -- tiles in this grid are this type -1 -- indeces in parent grid 7 3 -- texture list ========== BEGIN OBJECT ========== -- texture list 16 DATAd1861526EF495BC.RAW DATAd1861526EF495BD.RAW DATAd1861526EF495BE.RAW DATAd1861526EF495BF.RAW DATAd1861526EF495FC.RAW DATAd1861526EF495FD.RAW DATAd1861526EF495FE.RAW DATAd1861526EF495FF.RAW DATAd1861526EF4963C.RAW DATAd1861526EF4963D.RAW DATAd1861526EF4963E.RAW DATAd1861526EF4963F.RAW DATAd1861526EF4967C.RAW DATAd1861526EF4967D.RAW DATAd1861526EF4967E.RAW DATAd1861526EF4967F.RAW ========== END OBJECT ========== -- texture grid references 0 4 8 12 1 5 9 13 2 6 10 14 3 7 11 15 -- night texture list ========== BEGIN OBJECT ========== -- texture list 3 DATAd1861526EF4963C5N.RAW DATAd1861526EF4967D5N.RAW DATAd1861526EF4967E5N.RAW ========== END OBJECT ========== -- alt (MSL) for each vertex 592. 544. 603. 603. 544. 596. 588. 603. 603. 587.27032470703125 556. 552. 603. 603. 587.27032470703125 612. 644. 603. 603. 587.27032470703125 596. 620. 603. 603. 556. -- high detail grid ========== BEGIN OBJECT ========== -- dimension in tiles 4 -- tiles in this grid are this type 1 -- indeces in parent grid 1 0 -- alt (MSL) for each vertex 544. 603. 603. 603. 603. 556. 603. 603. 603. 603. 580. 603. 603. 603. 603. 592. 603. 603. 603. 603. 588. 603. 603. 603. 603. ========== END OBJECT ========== -- high detail grid ========== BEGIN OBJECT ========== -- dimension in tiles 4 -- tiles in this grid are this type 1 -- indeces in parent grid 2 0 -- alt (MSL) for each vertex 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. ========== END OBJECT ========== many lines deleted -- high detail grid ========== BEGIN OBJECT ========== -- dimension in tiles 4 -- tiles in this grid are this type 1 -- indeces in parent grid 3 3 -- alt (MSL) for each vertex 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 603. 556. ========== END OBJECT ========== ========== END OBJECT ==========What is it specifically I'm supposed to synchronize? I'll post in a few minutes if method one works (full deletion of HDTL sections....-DK----David KohlFly! II v2.5.240Dell 8200 P4/1.8G, 1024MB RAM, Nvidia GF4 Ti4600 v41.09, WinXP Home Edition SP1.CH Pro Pedals and Yoke USB.

[dkohl 0]

Just ran Fly. Good news is that with the edited G11 file, I can now taxi from the terminal to the runway without "falling" into the ground. But two things:1 - I couldn't locate any HDTL area in 0,3 of G01.TRN:[/i] -- super tile 0 3 ========== BEGIN OBJECT ========== -- dimension in tiles 4 -- tiles in this grid are this type -1 -- indeces in parent grid 0 3 -- texture list ========== BEGIN OBJECT ========== -- texture list 32 C2958D8D00 957E8D7E01 7E7E7EA802 7E95A87E03 8D8DC29510 8D8D957E11 8D8D7E7E12 8DC27E9513 8DC28D8D20 C28D8D8D21 8D8D8D8D22 8D8D8DC223 C28D8DC230 8DC2C28D31 C28D8D8D32 8D8D8D8D33 6F8D2C00.RAW 6F8D2C01.RAW 6F8D2C02.RAW 6F8D2C03.RAW 6F8D2C40.RAW 6F8D2C41.RAW 6F8D2C42.RAW 6F8D2C43.RAW 6F8D2C80.RAW 6F8D2C81.RAW 6F8D2C82.RAW 6F8D2C83.RAW 6F8D2CC0.RAW 6F8D2CC1.RAW 6F8D2CC2.RAW 6F8D2CC3.RAW ========== END OBJECT ========== -- texture grid references 16 20 24 28 17 21 25 29 18 22 26 30 19 23 27 31 -- alt (MSL) for each vertex 544. 564. 516. 476. 448. 556. 532. 496. 444. 448. 556. 516. 476. 444. 436. 544. 544. 520. 496. 424. 556. 500. 508. 492. 428. ========== END OBJECT ==========[/i]Second, by editing the first file, I now get that "bug" that used to exist in fly where your plane appears to slowly sink below the surface of the runway as you move along the ground. See a screenshot below....So, I think I need the help with method two as I noted above. I would guess manually "fixing" the seams between the two adjacent tiles will do the trick, but in both cases, the HDTL elevations must be left in.NOTE: First picture demonstrates the very out-of-scale size of the runway. I accept wide runways, but this is clearly visually incorrect. On the final two pix, the shot was taken at exactly the same place (parking brake on).FINAL NOTE: I tried Nick's KDFW.zip file (referenced several messages above), but had no luck. See some pix I posted under his message.-DK----David KohlFly! II v2.5.240Dell 8200 P4/1.8G, 1024MB RAM, Nvidia GF4 Ti4600 v41.09, WinXP Home Edition SP1.CH Pro Pedals and Yoke USB.

[dkohl 0]

The two shots below are after downloading the file above. It did fix the sinkhole, but the elevations need to be fixed to match the taxiways.Hmm... this appears to be much more work than I thought.-DK----David KohlFly! II v2.5.240Dell 8200 P4/1.8G, 1024MB RAM, Nvidia GF4 Ti4600 v41.09, WinXP Home Edition SP1.CH Pro Pedals and Yoke USB.

[dkohl 0]

This is the last post of the night. I'm tired.I ran Flattenator again. I selected KDFW and hit "go" (or whatever it is). I then launched fly with the edited Gxx.TRN files in the right place. The sink hole is gone! That's good. But like with Nick's edits, I slowly duck under the taxiways and runways as I taxi eastward. So it appears that Flattenator is working properly, but it is gradually synching the elevations. Since the runways and taxiways are at a fixed height, as I slowly sink, the runways and taxiways remain at the default height, thus begin to rise.So here's the solution as far as I can tell - Level the entire airport at the height of the terminal (which appears to be correct). I would guess that means copying the elevation data from one super-tile part of one of the Gxx.TRN files to the other super-tile in the opposite Gxx.TRN. If I've learned anything from all the above, I would take the data from G11.trn (7,3) and copy it to G01.trn (0,3). But given that there was no HDTL data in G01.trn (0,3), not sure if that is correct.I'll look for responses tomorrow. Regards all.Hope nobody minded my single-subject posts tonight. I kept trying different things between dial-up sessions.PS: Nick suggested I re-TerraScene the files without DEM data. If I do so, won't that remove the shadows? I thought you needed DEM data to get ground shadows. Although, maybe this is not a big deal b/c Dallas is pretty flat anyway.-DK---David KohlFly! II v2.5.240Dell 8200 P4/1.8G, 1024MB RAM, Nvidia GF4 Ti4600 v41.09, WinXP Home Edition SP1.CH Pro Pedals and Yoke USB.

[Harald_Kraft 1]

Hi DavidI never had this slowly sinking problem, so I don't know the reason.There is no problem with the missing HDTL data in tile 0,3, as long as all HDTL-points in 7,3 defining the seam between 7,3 and 0,3 have the same value (which should be no problem, because the airport is flat.If the area is not flat, you have to interpolate the HDTL-points to make those 2 supertiles fit exactly.for example:The altitude of the corners of your supertile is: 100. 500.and only one supertile has a 4x4 HDTL, than those HDTL-points on the seam must have following elevations: 100. 200. 300. 400. 500.or sometimes you will get strange effects in Fly.Does that make sense ?To avoid problems, I recommand to make the airport entirely flat.Harald

[dkohl 0]

Not sure I understand above. Please forgive me for what appears as a mental block!Last night, I kicked off TerraScene again, this time skipping the import of all DEM data. I am at the office now and didn't have a chance before work this morning to try it out (lots of Snow fell last night in NY so I unexpectadly had to dig out my car to get to the train station).I will try flying tonight with this revised TerraScenery at KDFW. According to Nickster, this should solve my problem, even if it is "cheating" a bit. I will report back tonight or tomorrow.In the meanwhile, I will keep studying the relevant files side-by-side. Perhaps this will clear the current mental block I seem to be having.-DK----David KohlFly! II v2.5.240Dell 8200 P4/1.8G, 1024MB RAM, Nvidia GF4 Ti4600 v41.09, WinXP Home Edition SP1.CH Pro Pedals and Yoke USB.

[Guest Dean]

>PS: Nick suggested I re-TerraScene the files without DEM >data. If I do so, won't that remove the shadows? I thought >you needed DEM data to get ground shadows. Although, maybe >this is not a big deal b/c Dallas is pretty flat anyway. David,I don't think it will as I believe the ground shading is created separately from the elevation data. Using the default data was the approach I took when I had this problem. Since the two entire globe tiles hardly vary with regard to elevation, I don't see any difference when I use the USGS DEM data versus the Fly II default. Below is a screenshot of the D/FW area slightly NE of KDFW using the default elevation data and I think the ground texture just below the A/C shows the effect of shading.

[Guest]

Dean is correct here. Terrascene uses high detail DEM data to generate the shadows which are then permanently a part of your terrascene-rendered area. The shadows are actually drawn into the ground tiles. They are not generated within Fly and therefore do not rely on elevations in the sim.

[Guest]

David, I screwed up the east end of the airport. I needed to "flatten" one tile farther east (and south I think) than what I did. I think that is what is causing the sinking problem.You don't really need the high detail grids in the airport area because the entire airport should be at 603 feet. Notice in your first post of the trn file that a few points were at 587.something feet? Those are some of the points that need to be at 603.I've begun slowly working on some graphics to put together a "little" tutorial concerning this subject. Maybe I can make a special effort to get a fair bit of it complete this weekend to help you out. The illustraions I'm working on should clear things up a lot. It really isn't that hard once you have a good grasp of how it all works, and now you've got me determined to make this easier to understand. ;-) In the meantime, your new terrascene project should take care of this for you.nick

[dkohl 0]

A combination of a tutorial + an update to Flattenator will do just great.-DK----David KohlFly! II v2.5.240Dell 8200 P4/1.8G, 1024MB RAM, Nvidia GF4 Ti4600 v41.09, WinXP Home Edition SP1.CH Pro Pedals and Yoke USB.

[Guest]

Well, I don't think I'll have any more time this weekend to work on this, so I'll just put out what I've done so far. It's rough. ;-) I've been writing it in Word 2000. There is just the Word document inside this zip file (which is 1.14MB):http://users2.ev1.net/~nik2/TrnTut.zipUnfortunately, I only got all the background information done. I haven't got to the actual editing of the terrain files around KDFW. If any one else reads it and has comments/corrections, I'm all ears.nick