Mapping For ONS

In Onslaught (ONS) two teams compete to build a chain of Power Nodes from their Power Core to the other team's Power Core whereapon it can be attacked. The game ends when one of the Power Cores has been destroyed. The game restricts the Power Nodes that can be attacked by linking them together in a specific structure. Onslaught also makes extensive use of vehicles.

Fundamentals

To create an onslaught map, the absolute minimum is to have two powercores, spawn points for two players, and you must set the DefaultGameType in LevelInfo to Onslaught.ONSOnslaughtGame. Without these conditions the game will not apply the necessary rules for the game to work.

Map size

Onslaught maps are typically outdoor environments and as such are much larger than maps for the other gametypes. The smallest Onslaught map is probably around the same size as the largest Capture the Flag or Bombing Run map. The gametype supports these large maps in the following ways.

Combat is concentrated around around Power Nodes. In general only one or two Power Nodes will be attackable at any one time.
Players can teleport between Power Nodes their team controls and their base as long as the Power Node is not under attack. This allows rapid travel across the map.
Players can spawn at any Power Node their team controls as long as it is not under attack. This allows a moving front to be developed.
Vehicles allow players to cover ground much faster than they can on foot.

Given the size of the map, ensuring the map is optimised well and has a good framerate thoughout becomes much more important.

Use of the Z-Axis

Making effective use of the Z-Axis within Onslaught maps is very difficult. The map showing the Power Node locations is a purely 2D construction and provides no clues as to the height of a Power Node. Having to work in an additional axis will generally mean that the map is not as instantly accessable as it otherwise might have been.

Slopes, hills, and mountains are all good things to have in your map. Not only do they help provide the map with some crucial variation, but they can also aid map optimisation.

Avoid excessive use of thin paths across instant death precipices. These can make vehicles almost useless in sections of your map. Also some vehicles don't handle that well close to an edge.

Power Node placement

The location of the Power Nodes on the map is one of the crucial factors to how fast or slow your map will play. Maps that are sparsely populated with Power Nodes will feel much larger than they perhaps are in reality, and the pace of the game will be reduced as a consequence.

Remember, the farther apart the Power Nodes are from each other the longer it will take players to travel between them. Spare a thought for the foot solider. A player who finds himself spawning at a Power Node or Power Core with no available vehicles has two choices. Wait for a vehicle to spawn or start running. Ideally the jog to the next Power Node shouldn't be too long. ONS-Torlan has the Power Node distances about right whereas the foot solider on ONS-Dria is in for a long and dull walk.

Each Power Node should have its own set of player spawn points. These spawn points should be spread evenly around the node. Place them such that newly spawning players can easily get to either a vehicle or a weapon locker (preferably both).

Avenues of attack

It is very easy to make a Power Node extremely difficult to hold once it is controlled. The hovering energy sphere that each Power Node has can be used as a target from a significant distance. Use slopes, trees, and other features to restrict the angles and distance from which the Power Node's energy sphere can be attacked.

It's also worth considering adding shortcuts for players on foot that are not available to players in vehicles to add additional tactical considerations to the map – or simply to reudce the amount of time spent running to a Power Node.

Link setup

To design the various Link Setups for the map, play the map and in-game, hit ESC to bring up the menu. Then click on Link Designer. The nodes and cores that have been placed should be seen on the map and a link setup can be made and saved.

The way in which the Power Nodes are linked together can radically alter the gameplay of the map. This happens for two reasons.

The path that must be followed to traverse the map (link one base to the other) is determined by the link setup.
The vehicles and weapons available to teams is based upon the nodes captured.

An example of this is linking the tank node on ONS-Torlan with a teams base rather than the primary Power Node. This has the effect of allowing a 2 front attack on the primary node making it significantly harder to control. It also means a tank is always available to both teams.

Typically only one or two Power Nodes will link directly to a Power Core although the actual number is really determined by the map design. Having many links to the Power Core can dilute the pace of the game though so be careful when doing it.

Try and avoid having a single node in the center of the map acting as a choke point linked to from more than two nodes unless there is a significant chance that the node can be held long enough for one of the teams to advance. ONS-Primeval is a good example of this. Without the tank at the central node it would be impossible to hold it long enough to mount any sort of attack on either the next node or the Power Core.

Consider creating link setups that allow a team to isolate an enemy power node. ONS-Dawn is a good example of this. If one team is building the power node on one side of their enemies base the other team can work their way down the other side of the map and then cut across in the center of the map. By holding the two central nodes they have isolated a node and are in a good position to mount an attack themselves. Having these sorts of outflanking manoeuvers available to teams can add significant depth and replayability to a map.

Vehicles Overview

There are the stock vehicles that came with the original release of UT2004:

Raptors are excellent against land and air targets but in a sky full of Avrils they won't last too long. They can be a very quick way of getting from A to B as they are not tied to the terrain unlike the rest of the vehicles.
Tanks are powerful and slow moving. Use their lack of speed to offset their devastating firepower. The vertical angle at which the primary tank gun can aim is restricted so Tanks can be disadvantaged when travelling on slopes.
Hellbenders are a good way of moving a bunch of people around quickly, and are excellent at destroying infantry. Put them up against a tank and they won't last too long.
Scorpions are reasonably fast and can be an inconvenience to soldiers on foot. They are good for taking out Power Nodes and Mantas. A fully charged bola does a suprising amount of damage.
Mantas are a very fast way of getting around, but get killed easily. They are excellent against Tanks without Avril support. The Manta's primary fire is an excellent way of taking out Power Nodes from a long distance. They are also good for squishing players on foot.
Leviathans are very big, very powerful, and very slow. A fully manned Leviathan is quite fearsome - when it eventually arrives.

Additionally, there are ECE (Editor's Choice Edition) vehicles. These vehicles are considered stock by the community and so you should not ignore them. Most new maps these days include ECE vehicles.

Cicadas are the most powerful weapon for taking down a node, and are not nearly as good at other things. They can take down tanks and Levis faster than any other vehicle, when used by expert pilots, but it is more risky than using a Raptor to do so if the enemy team has Raptors of their own in the sky protecting their tanks and Levis. Raptors can easily take down Cicadas. Almost all pilots have a very tough time killing ground troops with Cicadas (because it is HARD especially with higher pings).
SPMAs are great for shelling contested nodes near the center. They are sometimes placed in such a way as to defend the enemy's primary node once it has been captured, which is an acceptable use of them. But you should avoid placing them in such a way as to suggest their use in spawn killing the losing team at their power core. That is not fun for the losing team and players will hate your map.
Paladins are for defense. Defense! Got it? They are for shielding nodes and killing nearby attackers. They are NOT for cross country rides to grandmother's house.

Vehicle Placement

The golden rule here is balance. Your vehicle placement is the PRIMARY way in which you can directly affect how much power the winning team has against the losing team. Generally each Power Node will have between 2 and 4 vehicles associated with it. The larger the map the more vehicles will be needed as travelling between Power Nodes on foot becomes less attractive and less effective.

For making maps that really shine in gameplay, and support the kinds of strategies and tactics experienced ONS players would like to use, follow these tips:

Try to limit the placements of tanks. Prefer to place them in the base AND/OR at a central contested node. Avoid placing tanks at other nodes as this generally gives the winning team too much of advantage over the losing team.
A similar reasoning applies to Leviathans. They are best placed at each power core OR at a single central contested node (but not both). Giving the winning team more than one Leviathan is a BAD idea.
Paladins are slow and vulnerable critters. But they make excellent defense vehicles for nodes. Not only can they sheild the node, but they can even kill ground troops that get close by using the Paladin combo (while sheild is up, press fire to make a local shockwave for personal defense). Place Paladins ONLY at or near primary or secondary nodes. Do not place them at a node that is far away from the nodes they would be useful to defend. Avoid placing them at the power core, unless it is a short drive to the primary node.
Avoid placing Mantas all over the map at various nodes. Giving the winning team a hell of a lot of Mantas is a bad thing. It makes it nearly impossible for the losing team to make a comeback when they are constantly being roadkilled, and every time they get their primary node back up, 5 mantas attack it again. Prefer to put 2 or 3 Mantas at each power core, and a sparse number at various nodes throughout the map.
Scorpians are great for taking out tanks, as well as mantas in narrow channels. You may wish to place them with these goals in mind to help the losing team fight back.
The Raptor is the most versitile vehicle of the lot. It can be used to take out enemy aircraft (both Raptors and Cicadas), sniff out enemy snipers and campers hiding in trees and rubble, kill tanks, Levis, Mantas, and so on. In fact, the best use of the Raptor is as a predator of other vehicles (thus its name). There really is no substitute for this. Cicadas are NOT good replacements for Raptors (why? because enemy Raptors 'eat Cicadas for lunch.'). Do not think placing a Cicada at the power core will be sufficient. You should always have at least one Raptor there. This gives a losing team at least some chance of fighting off the tanks and Levis that are slaughtering them, and makes the game more interesting and comeback-possible.

Weapon Placement

At the Power Core make sure there is a good mix of hitscan and projectile weapons. There's nothing worse than trying to take back a Primary Node only to find that your best weapon is the short range Flak Cannon (Remember that the Link gun is much more important in Onslaught than in many other, if not all, gametypes).
The Weapon Lockers at each Power Node should contain a different selection of weapons. As with the Power Core a mix of hitscan and projectile weapons is preferred.
A full Weapon Locker can be collected by any player at any time irrespective of whether it is next to a Power Node controlled by the other team.

Map Checklist

Have you set up the Power Node network? Hit ESC in game and click on the Link Designer.
Do you have any vehicles spawning at a Power Node that are facing the wrong way for one team but the right way for another?
Can you reliably teleport between all of the Power Nodes - arriving at the Power Node you expect (odd things can happen if node areas overlap).
Do you wishto ship more than one Power Node setup with your map?
Show level properties. Make sure LevelInfo.DefaultGameType is set to Onslaught.ONSOnslaughtGame.

External Links (Tutorials)

[Onslaught Tutorial] from psyonix.com
[Onslaught Tutorial] from angelmapper.com

Discussion

Tarquin: how do you define the power node network, and how do you ship alternatives? this article should link to relevant information, eg actor classes

Sweavo: pasted an external link to some of that info. It should be assimilated into here though I think.

enDLine.SPA: you have to play your map, hit esc to bring up the hud and click the map tab, then click link deisgner in the lower right. I also added an external link to Angel Mappers Onslaught Tutorial.

Category Mapping