Corellia: Past and Future

Spaghetti

the grinch
R2D2
Movie Battles II Team Retired
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Corellia, like many popular maps, has a long and storied history. It has existed almost as long as Movie Battles II itself and undergone multiple revisions with work contributed by several map makers. Earlier this year I began work on the map's first major revision in over a decade, and possibly its last.

Scroll down to the "Corellia 2020 Update" heading below if you only care about previewing the upcoming changes, but I strongly encourage looking at the history for a better sense of how much it has changed and more context for how the current update came to be.

A Brief History of Corellia
Original

The original map was created by L-5-R and =Profcorron= and released in 2005 with the very first Community Map Pack version [opinion]: While a bit crude looking by modern mapping standards, it really wasn't that bad compared to its contemporaries. Its gameplay, though flawed, was fun enough to make it a community favorite.

Redo

The Corellia redo was a collaboration between MBII team and CMP mappers (Frost, Juggernut, Plasma, and Yzmo). Eventually it was released in 2009 with the Community Map Pack 5.0. The redo focused on prettifying the map without any significant layout changes. This version was distributed side by side with the original until later CMP releases, where it become the only available version. [opinion]: The redo definitely succeeded in improving the map's visuals, but it was not universally well received due to seemingly minor changes that negatively impacted gameplay. For instance slower lift movement speed. The visual improvements unfortunately also caused performance issues, which gave the redo a reputation of "pretty but laggy".

Official

Because the redo version was one of the better CMP maps visually and its source was available, it was a prime candidate for being "promoted" to official status. At some point before V1's release in 2014, work began on sanding down the rough edges of the redo with optimization and removing some unnecessary visual elements. That, along with an extra five years of computing improvements, helped mitigate the performance issues to acceptable levels. Gameplay was also tweaked to address some common complaints.

Soon after joining the team I began working on additional gameplay tweaks for V1.1. The main changes were extra cover for the cargo room vents (floor blocking blasters) and adding the left side route from the business center (where the protocol droid is) to hangar. This is also where the artificial delay on opening cargo room doors to hangar was added, intended as a temporary fix to mitigate defenders rushing the entry lift corridor and catching the attackers in a chokepoint. The delay helped prevent that issue at round start, but was rather awkward and didn't do anything to prevent lift camping later in the round.

Unfortunately that "temporary" fix has been in place ever since. There were no further changes to the map beyond some minor bug / exploit fixes.

The Process (how the sausage is made)
A lot of people wonder why certain aspects of Movie Battles get updated while others are rarely touched. There are many reasons this can happen, but the most important thing it usually boils down to is someone being motivated enough to actually do something (to completion). The mod is a hobby after all, and the fuel for improvements in such things is necessarily passion.

Personally I have always enjoyed Corellia for its unique aspects like the vents and cargo room, but at the same time hated how unfair the map could be to attackers if there is even a slight imbalance between teams. This last February, after a dozen rounds playing as attacker on a fully populated server (and getting thrashed), I finally grew frustrated enough to fire up Radiant and do something about it. Part of it was also the feeling of work that had been left unfinished.

At the start I only planned to redesign the entry area and make a few other tweaks, as that was what I perceived as the most significant issue in public gameplay. Some ideas for this were brainstormed back in 2016, though the history of that discussion has been lost along with those forums. After finishing those changes I threw the result at the beta team with the request for someone to do a scrim with it. AOD and their public scrim initiative were the first (and only ones) that tried it out. While the few changes were generally well received, they did not have much if any discernible impact competitively.

Watching the scrim, along with input by some beta testers and devs, provided a lot of valuable feedback. Map feedback is a tricky thing though. Often it doesn't focus on the larger picture, like performance concerns or movement flow (where players choose to go most often and thus where fights tend to take place). It's easy to unintentionally make a map play entirely different if you're not careful. Even so, there is usually some small kernel in feedback that can be used as the basis for an improvement.

At this point the project kind of snowballed in scope. The major changes were a new entry to cargo room from the vent side route, improvements to the new catwalk route, a crossover catwalk connecting the two in cargo, and a second lift to the access vents in the cargo room. A second scrim was held about a month after the first. Fortunately the changes appeared to have the desired effect. Areas of the map other than the cargo room entrances had plenty of interesting fights, and the match was much closer overall.

With that confirmation, I began working on the final set of changes intended to make the secondary objectives (security center and generator) viable options for the defenders to hold, so matches could be more varied than just "who managed to hold cargo room". After that it was "just" a matter of updating graphics like layout, and automap, which in this case really meant redrawing everything from scratch. I was able to get some help with that from Frenzy, but it was still the most miserable aspect of the update.

Corellia 2020 Update
So that's a lot of words. Without further ado, here is the final result:


And a comparison with the last version's layout (main level only):

From here on I will be going though each changed area and describing the changes. If you don't care about the commentary, you can simply view the gallery by clicking below, though it does not include everything.



Entry Area

The landing platform has been expanded to accommodate the extra door and ensure plenty of room for spawning players to reduce instances of falling off (in theory that should be impossible now if players only hold forward without strafing). The area has also undergone lots of optimization.


The goal here was to make it possible for attackers to reach the main hangar door around the same time as the defenders, without any type of artificial delay. Removing the lift from that path was the most obvious way to reduce congestion, but that brings more choices - players still need to get up to the hangar level somehow after all. One option would have been stairs, but I decided against that as I felt it would still create too much of a chokepoint area. That left only one practical alternative - raise the landing platform up to almost the same level. That in turn created a new problem: How to deal with the performance implications?

I'm not going to do a deep dive here, but the basics of the engine's VIS system are fairly easy to describe. When a map is compiled it gets chopped up into sections, which are then used to determine what is rendered by the rest of the game depending on where you are located. This saves on performance because your client does not have to render the entire map and other player models at once, and the server only needs to network clients within the same map section. Simple enough so far. Where it gets complicated (and inflexible for map design) is the system expects "hard" breaks between sections if you intend to block visibility, which normally means walls. Poke a hole in that wall? Everything behind the wall, whether you can see it or not, is now visible if you face it (unlike modern engines which use occlusion culling).


The solution I settled on can be seen in the gallery above - splitting the entry into two doors (which helps further reducing player congestion and preventing attacker spawn camping) and carefully positioning two walls to block visibility between those doors and the one to business center and the rest of the map. This minimizes the potential performance issues by ensuring that you cannot see into attacker spawn from the business center and beyond, and vice versa.

A solid wall between two central doors would have also worked, but in testing being forced to navigate around it just after entering felt very clunky.



The final piece of the puzzle was what to do about accessing the commercial area, but that was actually quite easy. Reusing what used to be the main lift (entrance visible above in the lobby screenshot) works perfectly as players jumping down will not cause any delays, especially for a secondary route. This also satisfies a secondary goal I try to maintain out of respect for other map artists: don't remove anything if it can be repurposed easily.

Tapcafe




As you may have noticed above, the commercial area is significantly smaller than before. This is no accident as I moved part of that to where the hangar side route used to be and expanded it into a tapcafe. This extends all the way to the second door at the back of the hangar. I think this is a much better use for the area and more likely to result in some interesting skirmishes compared to the original location.


The door behind the bar grants access to a storeroom with what should be a familiar vent jump pad setup that goes up to the central hangar catwalk.

Hangar

The most significant visual change here is the floor, restored from the redo version of the map. It was removed from the official version because of complaints about being distractingly shiny (I think, memory is hazy). Here it has been modified to reduce that while also improving performance compared to its prior iteration. Gameplay wise there have been a few changes. New ladders located between the fighters can be used to easily reach the side walkways (it is still possible to use the forcefield lip, but this is better in the middle of a fight and more obvious to new players).


The observant may notice the catwalks are slightly lower, so there should be fewer camera issues when looking down from them. Finally, because the central catwalk is now a tertiary route for attackers to access the cargo room, the "mando" hatch has been removed as superfluous (and to slightly reduce defender advantage).

Cargo Room

Here is the attacker's closest cargo entry from hangar. On the right there is now a ladder and adjusted boxes, giving regular gunners an additional option for getting on top of the boxes. In the center rear there is no longer a door to generator (more on this later). On the left, between the boxes, there is a small cover area positioned for attacker use. On the opposite side of the same set of creates (not pictured) there are also two more of the same small niches.


This is the cargo catwalk lift anyone who has played the map should be familiar with. It now starts lowered and offset to the side, allowing for a regular floor on the catwalk above. This should make it faster to access, and the gameplay around it slightly more consistent as the floor cannot suddenly drop away. In the lower right of the image, the boxes have been adjusted so they are easier to climb and/or shoot over.


The defender spawn area has had some more significant changes. The hidden vent route is no more - moved to the security center's new location. Instead there is now another catwalk lift, giving defending gunners a quick travel option to the catwalk, and attackers another path to the access shafts and security center. More minor changes include a few extra small boxes for cover and mobility (you can now climb to the top of the rear box stack in two places).


This view from the back of cargo room lets us see the rest of the major changes. On the right you can see some extra cover around the door (designed to favor attackers) and the fact the door starts unlocked. The main reason this was changed was because of a bugged area portal which stopped working after the first time the door was unlocked (area portals are used to allow areas behind a door to be hidden when closed). The door being locked was generally not much more than a four second roadblock, and tended to be exploited by defenders for easy kills, so it being this way should hopefully be a general improvement anyway.

In the upper center you can see the new crossover catwalk. This change tends to favor defenders as it provides them two additional areas they can use to defend against the vents. This helps moderate some of the new attacker advantages so they are not too strong. On the left side you can see the new location for the remaining generator door. It still starts locked, but is now a bit farther back, and the hack side is facing the defender spawn, so it should be safer to hack if there is no one nearby to interfere. The area behind that also has some boxes removed to give a clear path from attacker's secondary spawn area.


The door on the right is the end of the new tertiary route from the hangar catwalk. Attackers can use it as high ground for long range attacks, drop to the boxes below, or roll into the adjacent catwalk thanks to the conveniently placed breakable grating.

During development I tested out a few different configurations here that involved ramps between the catwalk and door. While it would make practical sense for such a ramp to exist, I decided it gave defenders way too much of an advantage. It was to the point of it likely making the entire route useless to attackers (because of the ramp's angle you could almost completely conceal yourself while sniping or shooting the hangar catwalk).



If you look carefully in the first image above, you can see a new central vent shaft between the original two. This leads to a new cargo room area where attackers may plant a bomb.


The bomb opens up an entrance to the attacker's secondary spawn area. While this is not a great position to attack through if the defenders are focusing on it, it still serves the purpose of providing attackers another route if the other vent shafts are being camped. It also forces defenders to spread themselves thinner covering a sixth cargo room entry.

Generator



The generator area, including its hallways, have been widened slightly so regular gunners are less vulnerable to ambushes, and more players can attack or defend. The objective logic has also been scripted so everything is more integrated (for instance, hacking security center or destroying the generator will open all locked doors).

Access Shafts

The generator side of access shafts has been shortened due to the generator's new position, and the new lift location gives anyone riding up some immediate cover at the top.


The main part of the access shafts is now focused on the lift down to the security corridor, which is equidistant to the cargo room catwalks.

T-Junction


T-Junction was formally called "services corridor". The left door opens up to the generator hallway and its lift to the access shafts (pictured three images above). The right door is the entry from cargo room. While so many doors in close proximity is a little clunky, it is necessary for performance reasons (keeping the access shafts isolated while the doors are closed).


From the rear of T-Junction it is easy to see how much the hallway has been shortened compared to prior versions of the map. The extra doors also make it a bit harder for snipers to suppress the generator (since you would need at least two teammates to hold the doors open).

Security Center

The area around the security center has been redesigned to improve gameplay flow. Instead of the lift and all the doors being tightly packed together, there is now enough room to maneuver for both attackers and defenders. Best of all, travel time has not been increased at all (it is actually shorter due to T-Junction being shortened). On the right side, behind a breakable box, is the new entry for the hidden security center vent route. The middle door leads to the security center, and slightly to the left of that on the ceiling there is a sentry gun that also alerts defenders when it detects enemies.


Here is where the access shafts elevator terminates. Similar to the lift near generator, there is enough space to make unfair ambushes difficult.


A view of the security center, mostly the same but with some slight visual changes (main one being the floor cables restored from the redo version - and they do not clip).

Unchanged Areas
While most of the map has undergone at least some minor changes, there are a few areas that are essentially the same as before:
  • Maintenance Vents (lower ones)
    • Beyond the extra exit shaft to the cargo room, these are the same as before. Some have suggested it needed expanding, but I believe that would be a mistake. The vents are not supposed to be a main route, and now that attackers don't have to deal with lift congestion, instances of a half dozen rebels trying to squeeze through simultaneously should be much less common.
  • Sales & Trading (original bomb hack)
    • This already served its purpose well as a hub for attackers trying to be sneaky around the business center. The bomb hack time was shortened though.
  • Business Center
    • Nothing was really broken here, so nothing changed. The angle of the walls around the entry favors attackers, and they should no longer have any issues getting to the area quickly with the other changes.

Comparison Gallery

The images here are ordered as a comparison between all the different versions (where areas are shared).

Final Thoughts
With that we've reached the end of the Corellia visual tour. There are a few other changes that will be covered in the final changelog, but this is everything really presentable. There is also one more surprise, but I won't spoil that here. Everything presented is release ready and expected to come out with the next update. I am excited to see everything in action on public servers and hope I have done justice to a classic map like this. Thank you for reading.
 
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Appreciate the detailed mapping and performance aspects of the build and working with the engine.

Can't wait to give it a try.
 

The Unguided

Movie Battles II Team
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"Pet projects" hah? :D Looking forward to play this very much. Only the atmosphere of this map is cool, and now the detailed layout, will be fun for sure.
 

SeV

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This is looking pretty good. Corellia was one of my favorite maps for 5v5 scrims way back in like b18. Hopefully with these changes, it can become a good map for more players.
 
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This looks fantastic. Corellia is a classic and was one of my favourite CMP maps back in the day. Fascinating to hear you discuss gameplay elements and how changes were motivated by play! Looking forward to trying it out.
 
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