So we will need to replace what we just downloaded from the previous post?
yes! you can compare both, check out the borders. The new textures are at the same location as before:
MoonView/The old ones have been moved to:
MoonView/old/Now each tiles have a bit of other tiles in it. The height mapping tells by how much a texture should be shifted at a given location. Close to a boundary, if the shift asks for points outside the boundary, you see a seems. Previously, we were seeing a seem of the same color as the closest point on the texture. With the new border, you see what is in the adjacent texture. As far as I understand, this is exactly what you are supposed to see, so there is no seam left.
So there are no more visible frontiers between tiles ?
The trick works provided the texture shift required by the height mapping is less than the border width we put. For the Moon's flying I've done this morning, that works super nicely most of the time. But, if you go to the polar region with the huge craters, take a low flying, then the parallax asks for a shift larger than the border width, so there, I see far away a seem appearing again. It disappears when you get closer, or higher, this is the expected effect.
There are still some lines visible, but they're not mine, they are the ones from NASA/ASU! There is a missing pixel line in one of the polar cap height map, and, at the pole the lighting is quite different between different tiles. Nothing we can do here, up to editing the map by hand. We can complain though to these lazy researchers
But at low flying other issues appear. The parallax shift I am using searches for only one solution for the intercept of the line of sight with the heightmap. So distant deep craters at low flying appear to be "cut opened" because the line of sight finds an intercept for the inner wall and stops there. I am pretty sure well known methods exist to solve this, but I did not look into that...
And nice to hear you found a solution for the pole problem! Maybe we're getting FG-Earthview back from the sad future of no polar icecaps.
Yes, we would need good polar images, and some color matching, but that's possible. All the TIFF flags warning we see in the world textures are precisely datums, so all these images can be re-projected as we want with gdalwarp. I am currently testing what the new border method for NASA2FGEarthView gives!