I have created a bgl to lay an airport pictures directly on the terrain (lo-res, unfortunately).For each of the eight "squares" on the airport, I use the following:VTPDataArea 1, 1, 0, 0VTPLayer 7, 0VTPNumTexturesInLayer 1, 0VTPTextureId 0, 0VTPPolyCount 1, 0VTPPolyMethod2 4, 0, 0VTPPointXY2 9435, 4590VTPPointXY2 9690, 4590VTPPointXY2 9690, 4845VTPPointXY2 9435, 4845Does this look okay? It works fine. However, when slewing across the boundary for each grid for the first time, the machine hesitates. This did not happen with my other texture mapping programs, so I wonder if I am doing something wrong.The second problem is that the underlying terrain is "bleeding" through my terrain, causing variations in the color.On the other hand, it is creating some interesting "textures" which I would like to duplicate. (See attached)Thanks,Phil

Nevermind about part 1 of this question. I substituted Luis's excellent macro and it came up with the same result.The machine stills stutters when crossing the boundary. However, it appears that the stutter is not exactly on the boundary of the grid - or more correctly, on the boundary of the "area" (e.g. area 22_3) within the cell (e.g. cell 694_213). So, something else must be causing the stuttering.Still interested in the "bleeding" and the "textures".Some day I may actually know what I am doing.Thanks,Phil

Hi Phil.You might be able to stop the blending of underlying testures by placing a layer4 poly that is a black texture... then you layer7 will be placed over that.. just an idea.Dick

Dick,Looks like it's not bleedthrough. I tried several different landclasses and the same pattern shows up. Instead, it appears that the color variation is due to shading. Since my runway is laid right on the ground, there are small variations in the angle of the runway relative to the sun. So the gray (RGB = 128/128/128) is given different colors, some of which are very strange - purplish and greenish. Is there are shade of gray that doesn't end up with these strange complements?Still haven't figured out the texturing, but it sounds like that may be a mystery to everyone.Phil