VT help: Background texture scaling

[PlutonianEmpire]

Ok, I've been crunching numbers on and off for the past couple days, and I've seem to come to a brick wall.

I've introduced VT's to Belle Hades in preparation for another update, to be released in conjunction with my short story once I finish writing it.

I took a 20 x 17 pixel segment of the 2048 x 1024 map of Belle Hades, containing only an island, which has a radius of 5469.6462 km, and determined the cut region to be 335.6671... km wide (335.7491... km w/lat. stretching?) and 285.2713... km high, centered at 1.51617° N and 63.99944° E. I then inflated it to 4000 by 3400 pixels, and enhanced it using some of the tutorials here on shatters.net and my own personal flair, for use in VT levels 4 to 7, with a tile size of 1024.

I noticed that levels 4 and 5 of the island required me to cut out larger, square, sections of the original 2048 x 1024 texture, stretch them, and use them as the background texture surrounding the enhanced island, to minimize seams.

Upon viewing the finished VT in Celestia, I found that a tiny sub-island created through the enhancements was in the exact same spot as a location label I placed for my story. Not wanting to used the shrunk down image located in one of the level 7 tiles, which had to be 2560 x 2176 for use in level 7 1024px tiles, I located the sub-island in the original 4000x3400 texture, and and cut out a 16 x 12 pixel area, and enhanced it using the same techniques I used for the larger island. The image width of the sub-island is also 4000 pixels, but the height was only 3000 pixels.

Heavy number crunching revealed the new area to be 1.3424... km wide and 1.0068... km high, centered at 0.94951° N and 63.50049° E. This is where I ran into the brick wall, because I need to include the surrounding larger area in all the remaining VT levels (8 - 12). Even with a tile size of 8192 px, the max my computer can sustain, the sub-island's image area is only 2621 x 1966 pixels at level 12, so the original larger island still needs to be included as the background texture even at level 12.

Finally, here comes my request for help: How do I figure out how many pixels I need to cut out of the original 4000 x 3400 image of the larger island, and the new pixel sizes I need to stretch the cutout to, for use as the background texture surrounding the sub-island?

The remaining levels, 8 to 12, will all be 8192 tiles. (I don't need to do any latitude stretching as it is already provided for, as the responses I got in my thread in the Textures subforum indicate.)

[John Van Vliet]

--- edit ---

[PlutonianEmpire]

Not necessarily. I am using basesplit, but am not doing the incremental increases you just described. Levels 0 to 7 are all labeled in the ctx as having a tilesize of 512 (with the corresponding actual size being 1024 pixels). Levels 8 to 12 I want to use as 8192 tiles (meaning 4096 in the ctx).

EDIT: This is why:

vt_tile_info_1.jpg

vt_tile_info_2.jpg

At just the base resolution of 1024 pixels, the appearance of the sub-island is pitiful, even at level 12.