Sonic the Hedgehog (2006) uses a number of suffix "tags" in the filenames of its textures. Each of these have a very specific meaning that affects how the object is rendered.
Four Character Tags
Some textures contain a four character tag composed of two halves.
| Tag
|
Description
|
_ntxx
|
Tangent-Space Normal
|
_nwxx
|
World-Space Normal
|
_dfxx
|
Diffuse
|
_enxx
|
Environment
|
|
| Tag
|
Description
|
_xxnt
|
Tangent-Space Normal (Again?)
|
_xxsp
|
Specular
|
_xxpt
|
Punchthrough
|
_xxlu
|
Luminance
|
|
Other Tags
| Tag
|
Description
|
_nt
|
Tangent-Space Normal
|
_nw
|
World-Space Normal
|
_lm
|
Shadowmap
|
_zlm
|
Lightmap
|
_sp
|
Specular
|
_rf
|
Reflectance
|
_rfa
|
Reflectance + Alpha?
|
_df
|
Diffuse
|
_envmap
|
Environment Map
|
_dif
|
|
_dm
|
|
_pm
|
|
Textures can appear with a final single letter suffix. The only letter that does not appear as a suffix is _w. It is unknown as to whether these serve purely as an organisational tool, or actually affect rendering.
