The original plan for Marathon Infinity's solo scenario "Blood Tides of Lh'owon" was that it was going to be an add-on to Marathon 2. So new aliens and no new textures.

Reflecting on game 25 years later Greg Kirpatrick wrote:

"Infinity wasn't really supposed to have a story, but we couldn't do that, right?! And we didn't have many assets or money to do art, although we did end up doing some anyway. So we had to tell a story with effectively the same art assets and presumably the same characters. So the storytelling for it was hampered by all those things."

The story did require one new texture set however which would be called Jjaro.

Bungie released the first Infinity screenshot using these new textures on their website on 16 April 1996.

Then on 12 June 1996 they released another screenshot showing the new textures this time on an Infinity net level.

They also released two textures from the new texture set.

   

But why were all the Marathon 2 textures redone in Infinity?

Tuncer Deniz (Infinity Project Manager) takes up the story:

"Randy Reddig, one of Greg's co-workers, decided one night in July to redo the water texture collection. We all thought the original water collection in M2 sucked, so he worked on it. The end result was great, Randy did a great job.

Toward the end of July, we started to work on the demo. We wanted to get one out for Macworld Expo in Boston in early August, so we worked feverishly on it. Unfortunately, we missed Macworld but we did ship the demo on the last day of Macworld. The response to the demo was great. A lot of people like the M1-like levels and the new textures.

Soon after Randy decided to redo all the textures in Marathon Infinity."

Concerning the Marathon Infinity textures Aaron Freed <aaronjfreed@gmail.com> writes:

They're all completely remade; most of them share elements with their M2 counterparts, but the aesthetic is completely different. In general, M2 is more colourful but also more... cartoony, for lack of a better term. Also, M2 sewage is predominantly brown while M∞ is predominantly green, and M∞ Pfhor is predominantly a desaturated blue while M2 is predominantly... the entire visual spectrum, basically.

Aaron has put together a very useful side by side comparison of the textures used in Marathon 2 and Marathon Infinity (see below).

Aaron writes:

In order, the rows are:   M2 water, M∞ water,     M2 lava, M∞ lava,     M2 sewage, M∞ sewage,     M∞ Jjaro,     M2 Pfhor, M∞ Pfhor.
Jjaro is included to show that many (though not all) of its textures fulfil the same functions as their corresponding sewage textures.

Aaron makes the following interesting observation:

There are a few Pfhor textures in Infinity that have the Jjaro pattern overlaid, but if the Pfhor stole as much of their technology from the Jjaro as we're led to assume they did, that probably fits.

Aaron continues:

The textures are a large part of the reason Infinity took place on Lh'owon, and thus a large part of the reason for the time travel and multiple timelines; Double Aught didn't think they'd have time to remake all four texture sets, and it would've been ridiculous to set the sequel on a planet that looked exactly like Lh'owon, but wasn't. Randy remade all the textures near the end of Infinity's development cycle. This is also why most of the terminal images in Infinity show the maps with Marathon 2 textures.

Since the new textures were a last-minute addition, they also had to fulfil the same purposes as their Marathon 2 counterparts - it wouldn't have been productive to retexture dozens of levels that late in development. However, the aesthetic of the game changed a lot. I personally am glad each game has its own textures; M∞ looks off to me with M2 textures, and vice versa.

You can see some of the Infinity terminals that have legacy Marathon 2 textures below.

Apart from legacy terminal textures you can also see the Marathon 2 textures used in this officially released screenshot for the game. It first appeared on Bungie's website on 12 June 1996.

Even though it was using the Marathon 2 textures it would eventually end up on the front of the Marathon Infinity box.

This is what it would eventually look like.

Aaron Freed provides the landscape textures for Marathon 2 and Marathon Infinity. In oder they are:

M2 Day
M∞ Day

M2 Night
M∞ Night

Moon

M2 Space
M∞ Space

Aaron writes:

The "Moon" collection appears in both games, but is only used in M2. The "M2 Space" collection is only used in one level, "Requiem for a Cyborg", which is a pity, because it may be my favourite out of the lot.

Overall, I again think each game looks weird with the its counterpart's landscapes. I did run through M∞ once with M2 textures replacing the Water/Lava/Sewage/Pfhor collections, and with the M2 landscapes, and although very little felt out of place, the atmosphere just felt off.

The appearance of legacy textures in terminal graphics is not just common to Marathon Infinity. Marathon 2 has its share. Right at the start on Waterloo Waterpark we have the legacy daytime Lh'owon texture.

As explained on reddit Marathon (r/marathon):

In the Marathon 2 Preview and Marathon 2 Demo the first level Waterloo Waterpark used the daytime Lh'owon skyline (yellow sky). This allowed it to fit with the other two levels which also used the daytime Lh'owon skyline.

In the full game it was changed to nighttime Lh'owon so it would fit the next level. By the time you got to the 3rd level it was daytime Lh'owon. Nicely showing you the passing of time.

Just how many more legacy textures/map changes appear in Marathon 2 terminal graphics? Seven or more?

Where are Mark Bernal's initials?

The Marathon Scrapbook states:

Mark revamped and created a large portion of the textures,
making them not only useful individually but also as a unified group.
(He managed to hide his initials in one of the switch textures.)

They were found of course... see the Mark Bernal's initials section for details.