GXModel viewer supports command line usage. It isn't as feature complete as the UI, but it has what most people need.
The command line can be used with just command line flags or in interactive mode. Interative mode is activated with the -interactive flag and cause commands to be read from standard input. It reads one line of input at a time and tries to split it into commands/arguments. Then operates on them just like command line flags. This means multiple commands can be in one line of input.
The only command difference in flags between non-interactive andmode interactive mode is that the -interactive flag is not available in interactive mode and the -quit flag is not available in non-interactive mode.
GX Model Viewer Command Line Help
Description:
If no arguments are given, GxModelViewer starts in its normal GUI mode.
Otherwise the GUI will not open and it becomes command line only.
See the '-interactive' switch for interactive mode.
Usage: .\GxModelViewer [arg [value...]...]
args:
-help Display this help.
-interHelp Display help specific for interactive mode.
-interactive Start GxModelViewer in interactive mode.
While in interactive mode, GX takes newline separated commands from stdin.
See '-interhelp' for interactive specific commands and differences.
-game <type> The game to use when importing/exporting.
smb: Super Monkey Ball 1/2 (default)
deluxe: Super Monkey Ball Deluxe (beta)
fzero: F-Zero GX
-mipmaps <num> The number of mipmaps to make on import.
-interpolate <type> The type of interpolation to use with mipmap generation.
default: The C# default type (default)
nearest: Nearest neighbor
nn: Nearest Neighbor alias
-importObj <model> Imports the designated .obj file.
-importTpl <texture> Imports the designated .tpl file.
-importGma <model> Imports the designated .gma file.
-exportObjMtl <model> Exports the loaded model as a .obj/.mtl file.
-exportTpl <textures> Exports the loaded textures as a .tpl file.
-exportGma <model> Exports the loaded model as a .gma file.
-setAllMipmaps <num> Sets the number of mipmaps for every loaded texture to <num>.
Texture files should be loaded before calling this flag.
GX Model Viewer Interactive Mode Help
Description:
GX Model Viewer Interactive mode works by reading lines from standard input.
Each line of input works just like command line arguments, so each line can have multiple commands.
Input continues to be read until the -quit command is recieved.
The -interactive command does NOT do anything in interactive mode.
Special Interactive Mode Args:
-quit Quit interactive mode and exit the program.
That's because texture wrapping isn't supported on those formats. I'll attempt to figure out some way to hack it into or switch to another model format.
This appears to be a bug of the original packer used to create the TPL files of the game.
In this file, there's a 256x32 texture in I8 format, with 6 mipmap levels, which only has 0x2AC0 bytes of space allocated for it in the TPL file.
However, according to the I8 format, which has a tile size of (8x4) with 8bpp, the size should be:
256x32 = 0x2000
128x16 = 0x800
64x8 = 0x200
32x4 = 0x80
16x2 -> 16x4 = 0x40
8x1 -> 8x4 = 0x20
----------------------
0x2AE0
When reading this file, GxGma will read 0x2AE0 bytes of input, effectively taking an extra 0x20 bytes from whatever happens to be the next texture. This will "corrupt" the last 8x1 mipmap.
Since this problem, unlike the F-Zero GX CMPR bug, only affects a single texture on a single file, and it shouldn't have any negative effect in practice, it's unlikely to be ever fixed.
This is because those files are actually headerless image files, instead of TPL files. They aren't supported to pass the TPL repacking test.