Sign in to follow this  
scott967

Use of 0.75arcsec DEM mesh in FS2002?

Recommended Posts

I'm attempting to override the default terrain/elevation mesh data in FS2002 using a 1:50000 scale DEM data set I obtained for the area around St.John's, Nfld, Canada. I resampled the file which contains 1201x1201 dem points in a 0.25 deg square area (hence should be 0.75 arcsec resolution, which at my latitude is something like 12.5m).When I try to use this in FS2002 (adding a St.John's_DEM scenic area with just the resultant BGL) I do see an immediate impact. However, the default FS2002 terrain, especially the crappy coastline, still seems to be coming through.There's obviously something I'm missing. What is the most CORRECT way to exclude the default secenery elevation mesh?I've used Ground2k (version 4) to re-define the coastline but still the old coastline is still "showing through". I'm following the "Monaco" tutorial but it doesn't mention anything about how to override the base FS2002 terrain data.

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

Hi Jonathan:Your area at St. John's appears East outside the default FS2002 (FS8) LOD6 mesh area and would likely be a default LOD5 mesh, therefore any properly resampled higher resolution 3rd party terrain mesh should theoretically be loaded automatically for that area by FS regardless of its layer position as long as it is "actively checked" in the FS scenery library user interface.Assuming you have edited your FS2002.CFG file to set TERRAIN_MAX_VERTEX_LEVEL=21 (TMVL), based on your figures (taken at face value without doing the math on your mesh constructs myself) I would not expect to see FS2002 render your terrain details any farther than about 10.4 miles outwards from the aircraft due to the smaller FS rendering engine visual display radius associated with higher LOD mesh.The FS terrain details seen from your aircraft will quickly fall off down to the lower LOD5 resolution outside the visual radius of your 3rd party higher LOD mesh if you do not have other multi-LOD "buffer" mesh for the area in between that higher LOD mesh and the default LOD5 mesh.If you have a good grasp on the mesh making process, you might wish to create the other intermediate mesh LODs for use in your project area for best results in rendering both the near and distant scenery around your aircraft.As for the shorelines, assuming the coverage area of your higher LOD mesh extends into the areas you wish to correct, you must be sure that you have properly modified the shorelines and assigned the resulting Ground2K4 (G2K4) LWM and exclude files at compatible layer numbers in G2K4 (which can be a challenge in itself sometimes!) and loaded them from a "Scenery" sub-folder (ex: under your "St.John's_DEM" top folder) added for them in the FS scenery library user interface.Even after you have fixed the intended shape of your shorelines properly in Ground2K4, the default FS water flattens for the area may still alter your ability to render correct elevations around water bodies.The latter problem with default FS2002 "HYP*.*" or FS2004 "HP*.*" water flatten files can often be fixed using Steve Greenwood's excellent free FSTflatten utility (part of his free fstutilities.zip package) to write out a separate and precise flatten or un-flatten LWM or Area16 type "flatten" BGL:http://www.home.earthlink.net/~smgreenwood/resources-g.shtmlAlternatively you could "append" modifications to the default FS HYP*.* water flatten file(s) using SBuilder:http://library.avsim.net/search.php?CatID=...&Go=Change+ViewTo find out which water flatten HYP file is associated with that area, use Jim Keir's LWMViewer v1.3 and "follow" a live flight in FS around St. John's:http://www.jimkeir.co.uk/FlightSim/index.htmlOthers will no doubt be more recently familiar with the details of how these several steps are to be done, and perhaps they may add additional comment here on how to further solve your scenery development challenge.For a simple and wonderfully well-implemented correction of many (non-elevation mesh) terrain details such as water bodies, roads, etc. I believe Ultimate Terrain for Canada/Alaska would be an excellent investment:http://www.flight1.com/products.asp?product=FL1-UTC-001And last but not least, FS2004 (FS9) will 'interpret' LOD12 "mesh" information in its internal choice of slope textures, but apparently does not "display" terrain mesh morphology details above LOD11 per se, regardless of one's TMVL setting. FS9 however, would likely be a very worthy upgrade from your FS2002 and will probably be able to run most legacy sceneries and aircraft you may have; you could buy it 'new' as cheap as $15 to $20 USD if you look for it in a few places.Hope this helps! :-) GaryGB

Share this post


Link to post
Share on other sites

GaryGB,Seems we're the only ones in here?! Anyways - I'm still using Ground2K4 to create the corrected shoreline - which appears properly when I load the 0.75 st.John's DEM and then the Ground2K4 _3.bgl in the LWMviewer tool. Since upgrading to FS2004, I can't seem to find where FS now puts its world water/land class files? In FS2002, these were simple worldLC and worldWC.bgl in the root /Scenery directory. Another observation (in LWMviewer) is that when I load in my Ground2K4 generated BGLs, especially the _3 one which is supposed to define land/coast, LWMviewer reports "invalid LC" with a value of 255 when I move my cursor over Areas where the new coastline was placed, even though I have most definitely created a new LWM polygon encompassing the entire coastal region now, with type 62 (Cool Conifers)on the coast. I'm starting to wonder if there's something wrong with Ground2K4 - something to do with the "Use Raw" or "Update Raw" LC/WC options in the project perhaps?

Share this post


Link to post
Share on other sites

Hi Jonathan:Glad the screenies (posted elsewhere in these forums) of St. John's helped out with your project planning. You may wish/need to further modify FS scenery areas to your particular individual preference as a directly experienced local resident even after having installed UT Canada, and I certainly understand from my own experience how one might wish to see through to completion a project one has been working on for some time! :7 As to WorldLC.BGL and WorldWC.bgl, they were moved to [FS Install Path]SceneryBASEScenery in FS2004.I would need to refresh my memory on some of the intricacies of G2k4 to answer some of your questions; others here such as Luis Feliz Tirado ( who 'semi-anonymously' authored Ground2K_For_Beginners... whoops, sorry Luis! :-wave ), Edgar Knobloch (edgarone), Dick Ludowise (rhumbaflappy), and Holger Sandmann (to mention but a few) would have been much more experienced with Ground2K4 (G2K4) than I had thus far become when I last used it, but it probably has been a while since they used G2K4 also!However, an answer may be forthcoming here with a little patience; the worst that would happen is you'd have to transfer the G2K4 portion of your inquiries into the Scenery Design Forum to get some response. ;-)As a relative newcomer to this area of the forum system (I haven't explored AVSIM's other offerings too widely yet myself!), you may wish to note that the Mesh Forum always tended to be very specific to mesh production and theory etc., having indeed become a much quieter place in the last year or so.Most other scenery development related questions (including those to do with G2K4) tended to appear primarily in the Scenery Design Forum (with "G2K4" appearing somewhere in the subject field).For the record, which G2K4 version number are you now using?Please note that some FS default scenery file layer numbers are different in FS2004 than in FS2002; Holger has developed some new variations for use of layer numbers that may merit consideration too:http://forums.avsim.net/dcboard.php?az=sho...33952&mode=fullIn the mean time, check out this link on a possibly related topic in G2K4:http://forums.avsim.net/dcboard.php?az=sho...24077&mode=fullIt may come to down to the old "Land Ho!" factor (create LWM, declare a landclass, then put another LWM on top of it etc., but I will have to go back and read up on this to recall better.Also, be sure your new custom G2K4 LWM coastlines aren't still being clobbered by the default FS2004 LWM water flattens in the HP*.BGLs which accompany the water polygons and the shape of the default FS terrain mesh which still display even if the default FS mesh itself is substituted out by your higher LOD 3rd party terrain mesh.These default water flatten routines inside the FS2004 HP*.BGLs affecting the LOD13 cells you are working on can be "appended" using SBuilder, or "unflattened" using Steve Greenwood's FSTflatten utility which will output a separate BGL file.You can then place other custom LWMs for the actual coastline shape and elevations you want at a higher display priority in the FS2004 scenery library user interface and get the result you want.Apparently, to get best results with the SDK we all have to use LWM water "flattens" along with the FS terrain mesh because even if we use 'mesh clinging' water over the terrain mesh, resample doesn't always create consistently flat areas from 'flat' parts of the DEM source data when it is told to do so.Furthermore, the FS displayed mesh clinging LWM water polys/textures without underlying flattens would 'creep up' onto the shorelines and look terrible from a distance IMHO.It is my understanding that G2K4 creates the accompanying water flatten in the LWM BGL at the same time it creates the LWM water poly, regardless of whether we choose to have it also create a contiguous textured VTP shoreline. But our new G2K4 LWM water poly flatten info still gets overridden by the FS default water flatten, so we have to go do a 'search/copy/edit/append' or 'search/copy/edit/substitute' for those default Hydro Poly (HP) flatten data points disrupting LOD13 areas we want to modify.PS: Modified default files should never be distributed outside one's own computer without following appropriate procedures such as Holger Sandmann has implemented with default files he modified or substituted in his FS scenery projects (do a search and check out his excellent freeware and commercial sceneries for a better understanding of how this might be done with less risk of resulting chaos for the FS user community).Hope this helps! :-) GaryGB

Share this post


Link to post
Share on other sites

The version of Ground2K4 I have is Ground2K4 V5.1 09/11/2003 (this is what's in the Titlebar). I just learned there may be a more recent version?Meanwhile, I did some experiments yesterday with the creation of Areas within Ground2K4, in the 4 offshore areas where I have yet to get land to appear. It appears that anything I put in these locations gets "clobbered" by the default WorldWC (i.e. water appears, even when I force each area to be some non-zero elevation, which makes for some very strange views in FS2004!).I'll get UT Canada installed next before I do anything further. It's possible that it + my 0.75 Arcsec data may be all I need. Then, maybe I can concentrate in getting some photo-realistic textures in there ;-)!

Share this post


Link to post
Share on other sites

>The version of Ground2K4 I have is Ground2K4 V5.1 09/11/2003> (this is what's in the Titlebar). I just learned there may be>a more recent version?>Hi Jon:Check out this link for Christian Fumey's files and updates:http://library.avsim.net/search.php?CatID=...&Go=Change+View>Meanwhile, I did some experiments yesterday with the creation>of Areas within Ground2K4, in the 4 offshore areas where I>have yet to get land to appear. It appears that anything I>put in these locations gets "clobbered" by the default WorldWC> (i.e. water appears, even when I force each area to be some>non-zero elevation, which makes for some very strange views in>FS2004!).>Conceptually, (and its been a while since I did this myself!) I believe that in G2K4 one must first exclude areas and features to be replaced, declare land in those areas (Land Ho!), and then stack up more LWM/VTP features on different layer numbers in order to get it to render properly in FS.Getting water and land to show properly along coastlines in any legacy FS scenery tool has always been a P.I.T.A., IMHO.Welcome to the "Click-fest" (as Holger once called the G2K4 scenery making process)!Heh-Heh-Heh... now you know why I recommended foregoing the coastline stress, and instead using UT to fix most of the coastline issues, then fine tuning on top of that with G2K4 or other utilities afterwards! :-lol >I'll get UT Canada installed next before I do anything>further. It's possible that it + my 0.75 Arcsec data may be>all I need. Then, maybe I can concentrate in getting some>photo-realistic textures in there ;-)!Excellent; I think you'll be glad you got UT (I'm a happy UT-USA user).I'll look forward to seeing what you come up with next! :-) GaryGB

Share this post


Link to post
Share on other sites

Hello Jonathan,1. Concerning your land not showing over your new coast, the most common reason for this is insufficient land class coverage.Land class does not work by placing a texture on each individual Area (LOD 13 quadrant.) Instead, it assigns a value to each of the vertices of the Area. Then, depending on the region, season, and time of day, a ground texture centered on that vertex is displayed. The ground textures from the 4 vertices of the Area are blended together to avoid evident dissimilarities.http://forums.avsim.net/user_files/175788.jpghttp://forums.avsim.net/user_files/175789.jpghttp://forums.avsim.net/user_files/175790.jpgIf even one of the vertices is missing a land class assignment, then no ground texture will display there. So, if you are not seeing land, it is because there are not enough land class assignments.The solution is to extend the land class farther out from the coast so as to ensure that all the quadrants are covered.2. TMFViewer reports a land class null value of 255 over your new coast because there is no land class there. See above for solution.As for Ground2K4, there is nothing wrong with it and it is always a problem with user error.Best regards.Luis

Share this post


Link to post
Share on other sites

More on this topic:3. The default land and water class files in FS 2004 are in the:C:Program FilesMicrosoft GamesFlight Simulator 9SceneryBASEScenerydirectory. Files in the labyrinth of FS directories can always be found by searching one's computer.4. FS will always (almost) use the altitude mesh of highest resolution.Welcome to the wonderful world of FS scenery design. If I have missed anything, please do not hesitate to say so.Best regards.Luis

Share this post


Link to post
Share on other sites

Luis,Thanks for your very detailed help. I've attached a screenshot showing the most grevious error/situation in my project. I had to shrink this down quite a bit to fit within the AVSIM upload limit but I think this should work. I'm refering to the Cellgrid coordinates in my discussion below.While the new coastline is showing up, there are two serious errors that may be seen:1. The "missing land" problem, most obvious in 20:21. If I understand your Monaco example, I need to define some (non-water?) landclass at all 4 corners of this square. I've already done 20:20, 19:20 through 19:22 (and beyond). Would 20:22 suffice to define all four corners or do I also need to do 21:20 through 21:22? There is a similar situation further North on the coastline (you can see the problem starting in 21:19) but once I figure out 20:21, I'll simply use the same technique there.2. The original coastline elevation is STILL "holding sway" over the end product - even though I am using a very fine DEM (0.75 arcsec ~17m mesh size at this latitude). You can see the "ghost" of this coastline as an abrupt cliff-ridge which cuts NE-SW through 19:21 for example. Also, the new harbour is "filled in" to the south west in 18:22 (original harbour is approx. 1 cell west). The view out the cockpit is even stranger - my new DEM data is being used up to these "cliffs" but everything after that is at SL.

Share this post


Link to post
Share on other sites

Hello Jonathan,1. As mentioned, land class coverage must be extended beyond the coast in order to ensure that all the vertices of the Areas receive an assignment. Please extend your land class beyond the coast and into the water and this will solve that problem.2. This is not a problem with altitude mesh, but rather with the Water Mask. The Water Mask has an associated elevation, a value of 0 meters (sea level).Unfortunately, there is no way to exclude or override that elevation value in FS 2002 or FS 2004. So, when you draw a new Water Mask over the default, it will display the new water parts, but the default elevation value will still be there, flattening your new land.If you are using SBuilder, then you can append the default HP file and modify the coast directly there, save the HP and have a new default file with correct coasts and elevation.Or, if your computer can handle it, then you could consider FS X where the water and its associated elevation can be excluded in their totality quite easily, avoiding the problem altogether. Plus all the new and advantageous features of FS X.Best regards.Luis

Share this post


Link to post
Share on other sites

Luis,Excuse me if all this sounds dumb, but I am still struggling with some of the basic functionality of Ground2k4 (the help/user info is not always clear). I suspected something like this was happening (i.e. the default water mask was still setting Altitude=0). If this is the case, why does Ground2K4 even have the "Area Attributes" function where you can create or modify the land or water class? Also, there is also this "Invert LWM Mask" section which sounds alot like what you're refering to in SBuilder. Do you have any experience using this? Who does? It appears that you first turn this on (select the checkmark) then select either LOD13 Water, LOD13 Land, or Poly. I have no idea which one to use!!-Jon

Share this post


Link to post
Share on other sites

Hi Jonatahn:I am sure Luis will explain further that the "Water Flatten" (located inside the default FS2004 HP*.BGL files for your project area) that I referred to in a prior post is "flattening" the terrain mesh near your shorelines.This persists in spite of any excludes that G2K4 creates, and must be fixed by use of SBuilder or Steve Greenwood's FSTflatten program.I must leave for a meeting right now, but could guide you through Steve's method of fixing it perhaps as early as tomorrow (Wednesday), or perhaps Luis or some other kind person could walk you through doing it in Sbuilder.Alternatively, the UT Canada for FS2004 scenery replaces the default HP*.BGL files for both water body shapes and the matching water flattens and solves the problem from the moment it is installed.Yet another reason I find UT so convenient since it frees up my workload so I can devote my time to other FS enhancements! :-) GaryGB

Share this post


Link to post
Share on other sites

Hi Again:Jonathan, in preparation for working with either method to fix your HP*.BGL water flatten issue, you might wish to install and run LWMViewer3 and "Follow" a flight at St. John's over all the areas you are trying to modify and be sure that all scenery files associated with the area are displaying in the smaller pop-up style window; you may have to turn this feature on from an option in the LWMViewer menu system (I'm not at my FS computer at the moment).Among the various files (with 2-letter prefixes) which provide the components displayed in FS, please note the HPXXXXXX.BGL filename(s) listed as you fly or slew over the areas of concern to you.HP files cover LOD5 sized areas, and whereas in the past one had to recreate them from scratch with 3rd party datasets, now, enough is known from the fair documentation that was provided on this particular aspect of the FS2004 SDK that several parties have figured out how to copy/append with an accompanying partial or complete LWM file, or copy/delete/substitute with a partial file, the default FS2004 LWM code for water flattens.BTW: A 1 character change of attribute in the LWM code can interconvert water to land or make the entire polygon transparent, all with elevation data intact as assigned by the end user.The "Invert Water Mask" feature in G2K4 probably would toggle between Water and Land attributes in LWMs, but I should properly defer final word on that to Luis as the much more informed authority on G2K4.Hope this helps!:-) GaryGB

Share this post


Link to post
Share on other sites

I have LWMviewer v1.3 - I assume this is quite a bit older then LWMviewer3? I'll hunt around for this and install it. However, at this point my interest in checking out the coastal area would be purely academic (i.e. to understand it myself) since I'm currently in the process of getting and installing UT Canada. There are other areas in Nfld that similarly need desparate upgrading of Lake/Coastline topography. I did a quick check of one area in particular yesteday and discovered a very similar problem there (although this time is was water masks for inland lakes!). The bottomline seems to be that my 0.75 arcsec DEMs *are* showing through - but are getting trounced by the crappy default coastlines/lake outlines creating strange cliffs all over the place.UT Canada should get me close enough to the proper coastlines/lake outlines such I can use better DEMs for select areas, and then concentrate on other enhancements, such as good lankmark buildings and maybe even photo-realistic textures (like you've suggested before!).-Jon

Share this post


Link to post
Share on other sites

>I have LWMviewer v1.3 - I assume this is quite a bit older>then LWMviewer3? >>I'll hunt around for this and install it.>>-JonOOPS! :-eek Typo on my part; I meant LWMViewer version 1.3; to my knowledge there is no version 3 (although I'd love to see a version "3" successor to Version "2" released which was FSX compatible!) ;)I wonder if Jim Keir is considering such a project yet? :-rollGood Luck with your project! :-)BTW: Yet another wonderful level of FS splendor (this time in an already geo-corrected world with fairly well-rendered default water bodies) awaits you in FSX when you are ready to upgrade yet again, as Luis alluded to.And many thanks BTW, to Luis for his additional clarifications to the G2K4 info already generously provided in his original excellent G2K4 tutorial document! :-wave PS: The new "Ultimate Terrain X" (UTX) for FSX looks gorgeous as yet another special enhancement to FS; I don't know if UTX Canada is done yet, but would be well worth looking into!)Again, I'm not affiliated, just an appreciative user of Scenery Solutions' product line; check out the further enhancements in the FSX version:http://66.135.39.111/ultterrain/UtxUsaDemo.pdf GaryGB

Share this post


Link to post
Share on other sites

I think also at one time Jim Keir built a little utility that would remove an entire LOD8 cell out of the default HP9 file. Then you would create your own LWM polys for the sea within the "knocked out" LOD8 cells.I actually use LWMViewer 1.3 to generate a source code listing of the default HP file, and manually delete any LWM polys or area fills in my project area, and then recompile it using the tmf macros and bglc that are also used in Ground2k4. I'm kind of concerned if sbuilder actually appends all the default data correctly or not. The problem is possible copyright issues with edited default files. UT-USA and Canada replace entire LOD5 HP files with their own data. If required Sbuilder can help, since you can append a neighboring default HP file and properly join your polys/shorelines to default data outside of your project area.scott s..

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this