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Guest liberalgeek

DEM/Photoscenery.

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Hi All,I've rummaged through a lot of the posts in the forum here, including the beginer's guide. However, as I have seen many tools mentioned for photoscenery and DEM, it's rather unclear as to where to obtain the best sources of data, and the appropriate program to use to obtain the best results. Needless to say, having everything in multiple posts is senseless and creates a large amount of distortion into the concept and confusion. I'm looking to do a small area, and have no idea of where to start, or what kind of data is best. I was going to use FS Resample Tools to accomplish the task, but I can't even find a help file explaining what kind of data it takes. It's turned out to be absolutely useless given that factor. Any ideas?Allan

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Hi Allan:Are you wanting to do a small "flat" area on and immediately surrounding an airport flatten for example, or do you want to cover much larger areas and have the custom photoreal textures "cling" to the terrain mesh of the scenery?Having just tried researching this subject myself recently, I share your concern about the scattered snippets of information on this (and many other FS-related topics) requiring vast amounts of time and effort to locate and interpret. This is very inefficient and vulnerable to potential loss with the passage of time; there are still many excellent insights and ideas by the FS community out there which should be archived for posterity (if one can just find them and and establish a safe central repository to keep them in)!Often when a particularly informative post is found, AVSIM has already "done the nasty" and deleted within a week's time the carefully-prepared images uploaded by a person seeking help with something, or by a generous soul who is trying to help others to understand something. This is appallingly disrespectful to the FS community members who are the ones that have made the "free service" of the FS forums truly relevant and meaningful; if "a picture is worth a thousand words" when clarifying a complex FS subject, it should be kept available for the life of that forum as learning resource, rather than compelling us to use more words in text form for fear that graphic images will eventually be deleted and lost from their intended and valuable purpose. :-zhelp In short, disk space is very cheap nowadays; the time, trust, and investment in learning of FS community forum participants is not, and I do not personally see any justification for deleting learning resources from a technical forum such as this one just so that elsewhere the latest showcased many-megabyte sized downloads can have space (for heaven knows how long!) on the AVSIM servers before "archive time" finally comes!!! :-8 Other posts are worded in such a terse and obscure manner as to be only understood by those who already have a more than basic grasp of arcane FS subjects. Although we should always be grateful for any effort by anyone who takes time to post, perhaps the FS community might also benefit in the long run from some further consideration being given to clarity in one's posts. If we can help the beginner to acquire at least a rudimentary topical orientation, who knows whether that person might accelerate their learning and end up creating an excellent FS add-on to bring us all greater enjoyment in the near future (freeware or payware!).I am sure we all appreciate the efforts of those who have posted things during the course of their own learning process, and who wrote and posted free tutorials when they had a given methodology down (before the constant and inevitable changes in the FS platform moved technical methodology into yet another direction and made such information outdated).As methods evolve and new versions of the FS SDK are released, one must always be studying the rather minimal SDK documentation and cruising the FS forums here at AVSIM and elsewhere to keep up; it is indeed very time-intensive.I believe the FS scenery design community might benefit from a further expanded and updated "Beginner's Guide to Scenery Design" with a table of contents having sectional thread targets, and hyperlinks to pertinent threads here at AVSIM and externally at other FS scenery related forums. This might help reduce the amount of time and effort (countless "person-hours!) expended by the FS community as they try to get oriented to the FS scenery design process via the search engines. Many thanks, though, to those who have contributed to the one we have thus far!Well, I guess I should step down from my soap box now! :-roll :-lol In the mean time, using the search engine at AVSIM, may I recommend that you conduct a query using "photoreal" and "resample", "custom" and "resample" for starters.Also, do read the documentation for the FS SDK pertaining to Custom Terrain Textures in FS2Kx, as various developers are using either FS2000 resample, FS2002 resample (version 1 or 2!), and the FS2004 resample to create photorealistic "custom" textures; read the FSX SDK docs too!There is also the option of using textured VTP (type 1 or 2!) polygons in FS2Kx and even applying them as "decals" in one's scenery; these are nearly always made as flat objects, although there may also be methods to divide polygons into triangles and map texture segments onto the vertices for smaller segments of non-flat areas.As to calculating extents of imagery for resample to create custom scenery textures from, for very small areas, Elrond Elvish's FS Resample Tool utility has been popular with some; however, it does not use an arc degrees per pixel computation which limits its accuracy over larger areas.Several other tools which seek to "semi-automate" the photo scenery development process merit consideration:Takuya Murakami's freeware utility uses the appropriate arc degrees per pixel approach, and has gained some popularity recently for FS2Kx photoreal scenery creation.http://scenerytools.sourceforge.net/Misho Katulic's "TerraBuilder" utility is reportedly still a viable program for FS2Kx photoreal scenery creation, and is available in a freeware "Lite" or payware "Pro" version.http://www.terrabuilder.com/It is important to remember that no matter what version of FS SDK one uses, true photorealistic custom terrain which is mesh-clinging will be a type of local "custom land class" in the WGS84 projected FS quad-tree world model.In FS2Kx, these special custom landclasses cover at least 1 LOD 5 terrain area using "transparency" attributes which allow default scenery tile display outside the LOD13 quads that display your custom texture BMPs. With photoreal tiles, alpha values of either 0,0,0 White or 256,256,256 Black in the BMPs allows display of custom land imagery vs default FS water.These photoreal LOD13 quad tiles are NOT blended at the corners of 4 such adjacent tiles as is done with default landclass tiles.INFs used with Resample to create photoreal LOD13 quad tiles may need to reference source imagery larger than the actual photo area to be displayed in FS by up to 1/2 of a neighboring LOD13 quad distance outside the desired area one wishes to display; the final photo area to be displayed must also be specified in the INF file.Custom photoreal scenery display by the FS2Kx rendering engine prevents display of other scenery components besides the terrain mesh (including all default or 3rd party VTP lines and features!) if those scenery components are located physically below the photoreal area BGL entry in the FS scenery library user interface.One can manually add autogen for use in conjunction with one's photoreal layer in the form of a custom-created autogen layer using the FS "Annotator" utility. In FS2Kx, VTP features can NOT be displayed in conjunction with "mesh-clinging photoreal" custom landclass scenery textures, but CAN be used and displayed with VTP photo-textured (commonly "flat") polygons (polys).In FS2Kx textured VTP polys , use of certain Landclass value "lookup" numbers are used for either transparency (allowing display of default FS assigned landclass) or other specified custom landclass types which the FS rendering engine blends at the corners of 4 adjacent LOD13 scenery tiles (if I understand the VTP poly rendering process correctly!). :-newbie Photoreal custom BMP textures are mapped to the fixed coordinates of FS world LOD13 257x257 grid vertices (not the 256x256 central pixel areas themselves!), and they always require a "placement" BGL created in Resample for FS2Kx; this will be associated with output of 24 bit DXT1 BMPs with Alpha and MIPs, (with or without seasonal variations) depending on what you request in the INF file you use with Resample.In FSX, the "photoreal" BGL in addition to placement parameters, will also contain variably compressed multiple resolution versions of the textures all in one big package, intended to assist with more efficient loading and use by the rendering engine. By contrast, in FS2Kx the rendering engine reportedly has to utilize MIPs and other information to achieve the desired real time display in FS.In FSX, the SDK allows the use of special "Blend Masks" to permit display of default scenery tiles (and VTP lines? :-hmmm ) as well as FS default water inside the area covered by a photoreal BGL (not sure I understand this feature, and look forward to learning more ASAP!).Various types of imagery source file formats may be used according to the type of custom landclass/terrain texture one is making, and depending on which version of FS Resample one is using.You might benefit from reading the original treatise on the FS world "Terra Model File Manual" generously provided to us by FS pioneering researcher Christian Stock:http://library.avsim.net/search.php?Search...=root&Go=SearchYou might also benefit from use of these Dick Ludowise (rhumbaflappy) utilities as tools for working with FS custom landclass and scenery development in general..."CellGrid2004a": http://library.avsim.net/search.php?Search...=root&Go=Search"TCalc2004": http://library.avsim.net/search.php?Search...=root&Go=Search and "PhotoCalc": http://webpages.charter.net/ludowr/PhotoCalc.zip(from this thread:) http://forums.avsim.net/dcboard.php?az=sho...25221&mode=fullHope this gets you started! :-) PS: As a relative newcomer seeking to fully understand these rather complex topics while helping another newbie, I would greatly appreciate anyone's further input and/or correction of errors here in this thread which might better clarify these topics under discussion. :-halo GaryGB

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That's actually a pretty nice write-up. "Resample" is designed to work on raster-type data. Finding good source data is the "holy grail" for terrain developers. For DEMs, the best large-area data have come from the SRTM program. This data can be augmented by local data, often derived from contour lines on various maps. IIUC, the contour lines themselves are generated by doing photogrametric analysis on stereo photography, augmented by geodetic benchmarks.For the US and Canada, high quality data are made freely available by national agencies. Elsewhere things aren't so nice. In most cases there are potential quality problems and there have been some suggested ways of finding and fixing things like no-data holes, data spikes, etc. I don't think there is any comprehensive site or tutorial on doing this. Once the raw data has been located and possibly cleaned up, it is necessary to get it in the right format. This requires ensuring it is projected in a geographic projection (each sample point is spaced by lat and long in degrees) and located on the WGS84 horizontal data. There are a couple of options for file formats, but for FS2x, generally band sequential based on 16 bit signed integer data is used. FSX adds the possibility of GeoTiff, using a single, 16 bit band.Coverage in FS2x generally requires that the data be clipped on LOD boundaries. I think in FSX that resample has relieved that restriction. Once the source data is prepared it is necessary to create the .inf file that resample uses as directives. This is where you tell resample how to resample the data (FS requires that all the data points be aligned within the LOD grid system). Photoscenery works much the same way. The main difference is that in FS2x the resampled photo data is output as a bitmap, which must be converted into DXT1 format. In FSX the resampled data is held in the bgl file as is the case of DEM dta. Photoscenery has some other wrinkles, in that there are options in FS2x to provide separate source photos for seasons and night. In FSX the seasons have been replaced by monthly photos. (I'm not sure this is a good thing, since there is no way in FSX to use the "seasons.bgl" to control which photo is displayed.) It is also possible to blend photosceenry with the "underlying land class / terrain texture. In FS2x and FSX it is by "masking" water areas. This allows for the wave effect and makes the water landable by float planes. In FSX, there is a new capability for a variable transparency which can be used to provide blending at the edge of the photo scene. It might also have some use in depicting inshore underwater objects, such as reefs along with floatable water.Most photoscenery source data is formated in a 24 bit rbg, or 32 bit rgba if water masking is used.the various tools out there are mainly directed at easing the process of clipping the source data and providing the necessary inputs to the .inf file.scott s..

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if you can wait to November, and go to the avsim conference, i have a solution!or if you really want my solution, email meliberalgeek at gmail dot comi have confirmed that it works!it is in game, photo scenery for a city.

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