I have failed to find any explanation what the 3_PLUS_1, 3_PLUS_4 and 7_PLUS_4 texture layouts exactly mean, and why they are needed. Anyone? I could also not find anything in the DirectX SDK documentation about these layouts, is this an FSX internal thing and not something DirectX would know about?I have read the SDK's Environment KitTerrain SDKTerrain Configuration File.html file but it just says, for 3_PLUS_4 for instance: "Three vertical strips and one strip with four subdivisions: one half, one quarter, and two one eighth sections." Umm, yeah, so? What are the half, quarter and eighth sections used for?Viewwing (using dxtbmp) for instance railroadsu.bmp, which terrain.cfg says to be in the 3_PLUS_4 layout, I fail to see anything speciual with the fourth column.I guess I could experiment and edit railroadsu.bmp to identify the stripes and check visually then in FSX how it uses them...

From the FS 2004 Terrain S.D.K.:In this structure, and in the default texture file, type refers to the layout of the texture. Currently only three texture types are supported. Each type specifies how line segments are placed in the texture, where the endpoints of each segment should blend with the endpoints of each other segment. Each of these types assumes a texture that is 256x256.

Hi there,to add to Luis's SDK excerpts: if you make your own textures using 3_PLUS_4 or similar formats then you need to ensure that all segments, including the short ones, are fully tileable; otherwise you'll have visible seams where segments meet.Thats why, in the example of the streams, the left three columns are quite "curvy" while the right column, with the shorter segments, is much straighter: the ends of each segment need to match the ends of all other segments.Cheers, Holger

Sorry, wrong picture 3 - here is the correct image:http://forums.avsim.net/user_files/177475.jpgPicture: Example of Type 3 Texture DivisionsBest regards.Luis

No problem, I got the idea. Thanks to you both!