I have a number of MegaScenery X titles (and some earlier MegaScenery titles too), and now I'm seeing products called "Ground Environment X" and "Ultimate Terrain X" packages. Today I got an email selling yet another, called "Flight Environment X."How do these three types of products relate to each other? Do they work together? Do they enhance each other? Are they competitors? Which is best?I'd appreciate your thoughts!BTW, I'm running FSX under the following configuration:

Hi,As far as I know (and I could be off on some of these):Megascenery = Sattelite imagery (no seasons?)Ground Environment = enhanced generic textures for ground (with seasons)Ultimate Terrain = Actual roads, rivers, streams, coastlines, and enhanced landclass boundaries, on top of generic ground textures.Flight Environment = improved atmospheric visuals, conditions & control.As far as interaction goes... not sure, curious myself. Though adding any of this stuff will probably kill my computer ;)

Let's start with GEX (and we can add FTX as well although the scope of FTX is larger).GEX primarily is a one-for-one replacement of the default textures used for displaying terrain. In addition to this, it places autogen objects (3d objects placed anywhere a specific terrain texture is used) on the replacement textures. It also has one for one replacements for textures used on autogen buildings. If you have UTX, it can also replace terrain textures from that addon with ones that color-match the GEX textures. Note that FSX supplies different terrain textures for different regions of the world. GEX only replaces those used in North America and Europe. Keep in mind, though, that MS never provided complete texture sets from every region of the world, and if a unique wasn't created the North American ones are used, so GEX North America can impact more areas than the title would imply. (In my experience it has a positive impact.) Because GEX replaces default scenery textures it is important to use the GEX configuration tool and take a backup of the default textures before adding ANY replacement terrain texture addon. That way, you can sure of restoring the default textures if needed and start over. (Same thing for any other texture addon like FTX.)Note that the use of any one of the various textures (default or replacement) is determined by a set of bgl files typically referred to as "landclass" but actually encompasses four files, worldlc.bgl, worldwc.bgl, seasons.bgl, and regions.bgl. "landclass" addons typically provide modifications to these files to control which texture is selected. Photo scenery aka custom terrain is designed as a replacement for the default terrain textures, and take priority over any default or addon terrain textures. BUT, one feature of photo scenery is that it is possible for the developer to blend the photo scenery texture with the "normal" texture, so in that case both are visible. This mainly is done at the edges of a photo scenery coverage and for water bodies.UTX is a primarily variety of terrain feature textures. These textures either cover a polygonal area, or are polylines. They are used to represent features such as roads, parks, etc. The actual placements are defined in graphics language (bgl) files. These features are location-dependent, so position accuracy is important. UTX also supplies its own textures for the features. The textures are "painted over" the base terrain texture while the sim is running so there is a concept of layering. MS calls the result of this painting over a "synthetic texture". Because the terrain features are location-specific, an addon like UTX is limited to specific world areas. But, if UTX is installed, in theory another addon could make use of the UTX textures (while supplying its own positioning data.Aside from it's core function, UTX provides a configuration tool which is a sort of "Swiss-Army knife" of tool for tuning your terrain feature textures (though this is a power-user feature and most people probably ignore the power available to them in this tool).FEX, REX, and some others have positioned themselves primarily as "environment texture" addons. This includes clouds, sky, sun, moon, etc textures. These are direct texture replacements for the default textures. To a certain extent they have also provided replacement for certain airport ground element textures such as taxiways and runways. The impact is global. You have to look at the product documentation and reviews to figure out what the overlap in texture coverage is between the products. They can also provide some real-time features, such as texture replacement based on current weather conditions.scott s..

First, let me thank both Turner and Scott for your prompt and informative replies. I appreciate your help, gentlemen!Turner, thanks for your concise definitions of the different products. That makes things a lot clearer to start with, and makes Scott's technical explanations easier to understand. If you do try the interactions, back up first, and best wishes for the enduring health of your computer!Scott, your technical explanation makes my head hurt, :( but that's nothing new. Below is what I understood you to say.I didn't know that MicroSoft had not created world-wide textures, but it doesn't surprise me, or bother me, since most of my flying and sightseeing are in North America. Beyond that:First, I think you're telling me that UTX will (or can) enhance GEX. But is that really the case, or are you saying that I'd be just as well off using UTX instead of GEX?Second, I think you're telling me that MegaScenery will sit on top of GEX and UTX, therefore effectively replacing them in the area the MegaScenery title covers. (By the way Turner, MegaScenery 2004 does not do seasons; MegaScenery X does.)Third, it sounds like FEX is for clouds and other atmospheric conditions. Frankly, I'm not that interested, so will go with the default.Since I already have a bunch of MegaScenery, I guess I should buy UTX and (possibly) GEX for the areas MegaScenery doesn't cover.Did I understand what you said?Barney