The low orbit views are now back to looking decent. I thought to a trick yesterday evening in my bed, while trying to sleep: using a dynamic texture scale, instead of a constant one. This makes the repeating pattern disapear at high altitudes, because the texture repeats less quickly than at ground level. The scale is dependent on the depth of the terrain patch (ex.: at level 12 of the octree, the scale is x32; at level 11, it is x16; at level 10, it is x8, etc.. ). Of course, there are now seams between patches of different levels, but there was already seams before, and it's not really much visible. If that really becomes a problem later, i can still use a per-vertex scale instead of a per-patch one, so that the scale value is continuous.
I've added an alpha channel to the detail textures, that encodes the bumpiness of the terrain. These are combined together in a pixel shader, to make lighting more or less strong depending on the surface (ex.: rock has a lot of bumps while grass has very little).
The next "big thing" to do now is to fix the texture popping problems, using alpha blending.
I've made a new 360? panoramic video to show off the detail textures on "Mount Showwhite".
Get it here (15.2 Mb DIVX 4)
Warning: it's a high quality video, encoded at 3500 bits/sec in 800x600. Due to this, there was some slowdowns while recording the video, so you shouldn't be worried about the performance. In real-time on my computer it runs at 130-150 fps.