   Terrain LOD and Skirting
  Terrain LOD is quite a popular topic on the internet, there are countless articles on the various techniques and systems, but very little on the way you can skirt around the edges of tiles to fill up gaps between different LOD levels.I currently have a chunked LOD system, which does the simple task of decreasing the LOD based on the distance from the camera.  Currently, a tile is guarenteed to be no more than one LOD level higher or lower, and will definatly have either two times, or half the number of verts.So I have a situation as follows   Lowest Level LOD   vvvv  v  v  v  v  v  v  v  v   Highest Level LODEdit: These verts are meant to have spaces between them, but the formatting has been lost!Does anyone have any information on how to fill the gaps between these LOD levels, either papers or tutorials?  I'm hoping that because there is a guaranteed number of verts on either side, it will be pretty simple.It is not important for the skirts to be created on the fly, as I am happy to pre-create the skirts for each tile.ThanksSpree   
  What you are talking about is not a "skirt". A skirt hangs down from a patch (like a skirt). It does not join adjacent patches together, so there is no need restrict the LOD of adjacent patches.The technique you described was discussed recently on GameDev and is generally referred to as "stitching". I believe Promit posted his algorithm and code at one point.   ;  Let's say your patches are like this (letters denote corners, dots denote edges):A.......B.. .. ...  .    ..   .   ..    .  ... .. ..C...e...D..  ..  .. . . . ..  ..  ..f...g...hThe problem, of course, is that the 'e' corner might not be on the same plane as the ACD triangle. The solution: split the ACD triangle into two. This creates no new vertices, just new indices. This is the correct solution; the vertices do not need to be altered at all.A.......B.. ...... ..    .. . .   ..  . .  ..  .  . ..   .  ..C...e...D..  ..  .. . . . ..  ..  ..f...g...h;  Eh, I prefer to remove rather than add. So if you start with this:Ok, I just finished trying to replicate CGameProgrammer's ASCII diagrams to demonstrate my method, and failed miserably. Basically, the triangles that use vertex e are moved to use vertex C. This means that CEG becomes the degenerate CCG, EGH becomes CGH, and EDH becomes CDH.   ;  I do understand your idea of removing verts, as the removed verts would be on the LOD boundry, so hopefully, the player would not notice the lower resolution.Thanks for that, its def one area I will look intoSpree   ;  Lemme drop in a screenshot to show what mine looks like. Keep in mind that the stiched regions are part of the high resolution patch.;Quote:Original post by PromitEh, I prefer to remove rather than add. Why?;  It's simpler to do, you simply go through the indices and scan for ones that should be changed. You change those into degenerates and you're done.(Also, a cookie for the people who can spot where the driver messed up the wireframe rendering.)[Edited by - Promit on February 27, 2006 6:00:35 PM];Quote:Original post by Promit(Also, a cookie for the people who can spot where the driver messed up the wireframe rendering.)A missing pixel around (979, 190) ? (origin at top-left)and quite some missing pixels around (300,130)   ;Do I win? It may just be an odd angle though...   