Is there a good way to reproject from mercator to QSC and re-tile map data that is in TMS format?

Question

I have several large data set in TMS tiled format (maps and satellite imagery). I am looking to apply them to a 3D earth model in Unity. My unity mesh is a Quadrilateralized Spherical Cube (QSC).

QSC has some nice properties in that there are no weird artifacts at the poles and level-of-detail texture-coordinate computation is simple, so I'd like to use that approach if I can.

Here has been my process so far:

1. Georeference tile images using gdal_translate.
2. Build a vrt from the resulting geotiffs.
3. Reproject the vrt using gdalwarp

This works nicely in that I end up with six tiffs (one for each face of my cube) and I can use them as low-resolution textures for my mesh.

Here is where I am stuck:

• warp processed my vrt into a tiff, but I don't think that would not work for a large data set. The resulting tiff would be too big. Is there a nice way to do this work in chunks?

• re-tiling with gdal2tiles yielded strange results. I used the 'raster' profile and I expected a quad-tree pyramid of tiles but the tiles appeared to be sub-divided along longitudinal boundaries rather than QSC grid boundaries. Is there a way to do this?

Answer 1

It turns out that my tiles are mostly what I need. I just didn't understand what I was looking at. The only weird thing is that there is transparency at the top and right edges. I will have to manually stretch the image and retile to fill the grid but that seems do-able.