Celestia Forums

Hello there,
I am looking for software that subdivides a giant texture (in my case, textures up to 64K) into smaller tiles for each level for a VT.
Does anyone have any idea where I can find such a software?
(EDIT: I have tried Ftex tools and I either cannot figure out how to use it or it does not work on my computer)

Gimp free software -> Image menu -> Guides -> Slice Using Guides -> export as DDS image.

I would but that would take my computer like 2 whole days to do and I plan to do 7 of 64K resolution and several at 32 or 16K resolutions.

i have a linux bash script i use to cut images into tiles
it uses the vips image library

other than this there is only frigers texture tools

the tex tools require that the input image be in RAW!!!!! format
the Gmic program is what i use to convert a png or tiff into a raw image

Shadow-Dragon-777 wrote:I have tried Ftex tools and I either cannot figure out how to use it or it does not work on my computer

Use 8192x8192 pixels tiles, so there will be only a few of them. Most video cards can handle that much.

possible for anyone to show him how to use the Ftex's tools (witch shadow said needs CMD, witch is confusing the living heck out of him)
or help him with troubleshooting the program and see why its not working (if this is the case) and get it fixed

Some members on the Discord server have been helping him with it, but it hasn't been working. According to John Van Vliet's post above, it's because the input images need to be in a raw format, like with NmTools. I've tried converting png images to raw images using both GIMP and (today) G'MIC for use with NmTools, but the results weren't much better.

Just recently on Discord, ajtribick suggested that F-TexTools and NmTools may not work on Windows. If that's the case, then probably the only way to create VTs on Windows is what john71 said.

SevenSpheres wrote:probably the only way to create VTs on Windows is what john71 said.

Gimp allocates the tx_ x_y tile designations perfectly, after that you can use a batch renaming utility to change the name of the Gimp exported tiles in one step.

You only have to export manually the tiles, which are 2, 8, 32 etc. manual exports.

I was able to create a 256k Mars VT manually, in a few days.

for the getting ancient fxtools libpng 12 MUST be installed




this is the std output of just running "txtiles" without any arguments

the input image MUST!!! be a raw image

use " png2bin" -- part of the texture tools package


that gives you a 8 bit raw image

then as per the std output above that tells you how to use it

you run ( for an 8 k image level3 vt with level 3 png compression)

FWIW, I use a bash script based on Fridger's original zsh script which uses ImageMagick's convert utility. It isn't particularly fast, but is understandable (to me, anyhow). I use Cygwin under Windows to provide a linux-like environment with bash and ImageMagick, although Miicrosoft's "Windows Subsystem for Linux" (available for free through the Microsoft Store) probably would work, too.

Performance greatly depends on the amount of RAM, too. When using this virtualtex script, if three copies of the original full-resolution surface texture image don't fit into RAM, the computer will "page itself to death" (i.e. run absurdly slowly) because it has to use on-disk virtual memory.

selden wrote:FWIW, I use a bash script based on Fridger's original zsh script which uses ImageMagick's convert utility.

I think this problem should be handled by the developers (?). Or maybe a Gimp plugin would be practical, because Gimp has excellent memory handling capabilities and can slice and convert any image file. Using RAW files is not a great solution in 2021. Using Gimp manual slicing also sucks in my opinion, compared to an automated solution.

Without future VTs Celestia is dead.

i use Vips image library and the Nip2 GUI quite a lot

here is my bash script

it takes as input a Vips ( *.v ) image and exports png tiles
a 64 k map takes about 4 min. to run

the script can also be edited to except any supported image format by un commenting out a few lines

Okay so, my best bet is to use Gimp to subdivide it?

Does the grid feature on Gimp act as lines for the guillotine tool or do I have to manually add each of the 126 lines? Also does Gimp allow bulk saving of tiles?

Sorry about the necropost, I was busy last month and this sorta got buried.

You should use 8192x8192 pixels tiles, so you have to slice only 2, 8 or 32 parts.

Use Image/Guides/New Guide by percent.

You need 1 vertical line in 16k (50%), 3 vertical and 1 horizontal lines in 32k (25%, 50%, 75% and 50% again).

At 64k you have to add 12,5%, 37,5% and so on.

After adding the guides, you slice in one step, but you have to export each new image manually.

You should also change the names: when there is ......0-0, the name should be tx_0_0.

I believe I may have found a shortcut that shortens this process greatly in Gimp. The filter section has a web slice function that I tested on a 16K Charon LOK texture I made and it seems to be able to do the job rather well, mass exporting the sliced images to PNG and adding a prefix to the tiles. though the guides still have to be placed manually before doing this, Gimp still to this day doesn't have a grid to guide transformation function. This tool shortens the process from taking a few days to taking just a couple hours. All I have to do is add the hundred something guides, put "tx" in image name prefix, and put it in the appropriately named level folder. Now to find a day where I have a few hours to do this.

Few questions:
Is 65536 pixel appropriate for level6 textures?
Are 1024 x 512 textures an appropriate size to use for tiles?

Shadow-Dragon-777 wrote:Is 65536 pixel appropriate for level6 textures?
Are 1024 x 512 textures an appropriate size to use for tiles?

Levels are like this:

level0 2 tiles
level1 8 tiles
level2 32 tiles
level3 128 tiles
level4 512 tiles.

If you use small tiles (like 512x512 or 1024x1024), it means you need a LOT of levels.

On the other hand if you use 8192x8192 pixels tiles you will reach 64k at level2, 128k at level3 and 256k at level 4.

Well, update: I was able to get the images made but... Gimp names the tiles backwards IE the x coordinates are the y coordinates. I had to manually rename each one to its correct coordinate which took a few hours. After this the Titan texture worked perfectly. I plan to eventually release it here once I get a VT closeup of the Huygens landing site.