This is from a quick python utility I wrote that parses an obj and builds a list of unique materials. Once the list is built, it sorts the list and inserts it above the list of verts...

Below is a snippet from running Victoria 3 through it.

To see what it does, insert the following at the top of the obj...

Begin Ordered Material List

g Materials
usemtl EyeSocket
usemtl Eyebrows
usemtl Eyelashes
usemtl Fingernails
usemtl Gums
usemtl InnerMouth
usemtl LCornea
usemtl LEyewhite
usemtl LIris
usemtl LPupil
usemtl Lacrimal
usemtl Lips
usemtl Nipples
usemtl Nostrils
usemtl PubicHair
usemtl RCornea
usemtl REyewhite
usemtl RIris
usemtl RPupil
usemtl SkinArm
usemtl SkinFeet
usemtl SkinForearm
usemtl SkinHand
usemtl SkinHead
usemtl SkinHip
usemtl SkinLeg
usemtl SkinNeck
usemtl SkinScalp
usemtl SkinTorso
usemtl Teeth
usemtl Toenails
usemtl Tongue

End Ordered Material List

Loading from a cr2, in pro pack it works fine (no geom .rsr to contend with), the list shows up as expected within the material editor. But, standard p4 could care less. Importing the obj (in either standard or pro pack) results in the list being the inverse of the ordered list (above) in the obj.

Inspecting the associated geom .rsr shows the list as:

SkinTorso
Nipples
SkinNeck
SkinHip
SkinFeet
SkinLeg
Toenails
SkinForearm
SkinArm
SkinHand
Fingernails
SkinHead
SkinScalp
Lips
EyeSocket
InnerMouth
Nostrils
Lacrimal
Eyelashes
Eyebrows
Teeth
Gums
LCornea
LEyewhite
LPupil
LIris
RCornea
REyewhite
RPupil
RIris
Tongue
PubicHair

Which is the order they appear in the obj (sans - inserted ordered list). Still, standard P4 doesn't follow this list either.

-Rob