ETRLE Image Engine (.STI)
The Jagged Alliance 2 asset engine does not natively support modern alpha channels or true-color RGB formats. Image arrays are compressed into the proprietary .STI format.
Mathematical Dimension Boundaries
The engine requires all character textures to be cropped out of a central canvas, mapped directly to specific aspect ratios utilized by the game's UI containers.
| Image Container | Resolution | Engine Function / Usage |
|---|---|---|
BIGFACE |
106x122 | The primary profile canvas shown on the AIM website. It features a taller vertical aspect ratio, exposing the neck and upper clavicle. |
FACES |
48x43 | The tactical HUD format. It utilizes a wider aspect ratio, omitting the shoulders and the top of the skull. This is the geometry from which the Eyex, Eyey coordinate overrides are derived. |
65FACE |
31x27 | The active squad selection strip at the bottom of the screen. Scaled linearly down from the 48x43 aspect. |
Animation Strips & Sub-Frames
A functional Mercenary SmallFace (48x43) is an index containing 8 nested graphic strips:
[0] Base Render (48x43)
[1] Eye Blink - Half (17x6 offset)
[2] Eye Blink - Full (17x6 offset)
[3] Eye Blink - Unused duplicate (17x6 offset)
[4] Eye Squint - Tiny (17x6 offset)
[5] Mouth - Slight parted (14x6 offset)
[6] Mouth - Wide shout (14x6 offset)
[7] Mouth - Mid syllable (14x6 offset)
255-Color P-Mode Index Constraint:
All sub-frames (blinking, talking) must share the exact same 255-color indexed palette as the Base Render. If an animation attempts to use a color that does not exist in the base palette block, the ETRLE compressor will corrupt the frame buffer, resulting in color artifacting across the mercenary's face.
All sub-frames (blinking, talking) must share the exact same 255-color indexed palette as the Base Render. If an animation attempts to use a color that does not exist in the base palette block, the ETRLE compressor will corrupt the frame buffer, resulting in color artifacting across the mercenary's face.