DDA Manifesto: Propulsion
Written by: lord_day
Index:
-What is a DDA?
-Propulsion
-Tiles
-Launch Pads
-Doors
- The Different Doors
-Trap Door
-Normal Door + Trap Door + Locked Door or gold delay
-Locked Door Glitch
-Thwumps
-False Tiles
-Gold Delay
What is a DDA?
A DDA stands for Dont Do Anything. A DDA is a map that you watch, as the ninja is moved around, through various means. Most DDAs will have the ninja finish the level; however some dont and will either purposely kill of the ninja, or make the ninja move around the level forever. Some DDAs are also more complicated than just a ninja moving around by himself. For example, some maps require the audience to hold right or left for the ninja to complete the level. Other variations on the DDA are maps that, for example, keep a rocket alive the whole way through a level, or use only one type of propulsion. Propulsion is what keeps the ninja moving, and without it, very little could happen in a DDA.
Propulsion
Propulsion is the mechanism that keeps the ninja moving so that he can travel from A to B. Unlike a normal map, the player has no control over the ninja, so the objects in the level have to move the ninja themselves. Here is an overview of the main types of propulsion:
Tiles
It goes without saying; nearly every DDA involves the ninja interacting with tiles. The tiles change the ninjas velocity when he collides with them. When colliding with tiles the ninja will either change direction or speed, depending on the angle of the tile and the angle of collision. Tiles can also give the ninja a safe place to land if he is falling from a large height. Tiles also add a protection value to the ninja; he is less likely to be hit by enemies if he is protected by tiles. Tiles can also be used to give the ninja speed. If a ninja is placed inside a tile, it pushes him out, adding to his speed. Consider the following maps:
http://numa.notdot.net/map/57023
In this map, every time the ninja collides with a tile it changes his velocity, by either changing his direction, speed or both. The tiles have been placed to manipulate the movement of the ninja so that he avoids the rocket and the mines.
http://numa.notdot.net/map/56097
In this map, the ninja is propelled into some tiles, which then propel him out, into the next tiles. Some of the tiles trap the ninja in a smaller are than he is supposed to be able to fit into, so this also adds to his speed, by effectively squeezing him. The tiles also change his direction, allowing him to turn around the map. The ninja was pushed through thin areas of tile, as to avoid risk of death, yet at greater speeds its possible to go through larger areas of tiles.
Launch Pads
Launch pads are one of the most common methods of propulsion as they are by far the easiest to use. They instantly add to the ninjas velocity, meaning that the ninja moves around a large distance without much thought. Because they can instantly change the ninjas direction, they can be used to make very close calls for the ninja. Consider this map:
http://numa.notdot.net/map/41616
The launch pads in this map are used effectively to move the ninja out of danger at the last possible moment, and to push him into a safe area. The launch pad only needs to be placed exactly where the ninja is going to be, and it means that timing is not an issue, as with most propulsions. The launch pad can also be used as a way to safely slow down a ninja who is travelling at a great speed in any direction, because a launch pad sets a ninjas speed to a certain level, it doesnt add to it. That said, it is possible to edit the speed that a launch pad will set the ninja to. A launch pads code looks like this:
2^396,468,0,-1
And by playing around with the last two numbers, you can change the speed the launch pad will set the ninja to. If the speed set is great enough, it is possible to teleport the ninja through objects, enemies or tiles. However, after this, there is generally something needed to slow down the ninja, otherwise he will die from high-speed collision. Watch this map:
http://numa.notdot.net/map/53244
At the end, the ninja hits a code-edited launch pad, sending him through the tiles, where he collides with a normal launch pad, bringing him back to normal speed. Code-edited launch pads can provide an easy escape or method of transport for the ninja, where ever he is on the map.
Doors
Im going to split the doors section up into four different sections:
-The Different Doors
-Trap Door
-Normal Door + Trap Door + Locked Door
-Normal Door + Gold Delay
-Locked Door Glitch
The Different Doors
A: Normal Door
B: Trap Door
C: Locked Door
Trap Door
A trap door can be used to push the ninja forwards. If the door is created, and there is a bit of the ninja in the door, he is effectively pushed out of the door. The more of the ninja in the door when the switch is created, the faster the ninja will be ejected. A general rule of thumb for creating trap door propulsion is to place the key ¾ snap from the door:
Watch this map:
http://numa.notdot.net/map/55684
You will see that the door is always created on top of the ninja, pushing the ninja, and the key is always near the door so that the door is created when the ninja is near it. The door can also be used to in the same ways as a tile, to change the ninjas velocity on collision. Finally, the door can act as protection for the ninja from most enemies.
Normal Door + Trap Door + Locked Door
This method of propulsion is more complicated. Firstly, to understand it, you must understand that if a trap door is created or a locked door is placed on top of a normal door, then they act like normal doors, allowing the ninja to pass, but deterring enemies. However, if the ninja picks up the key (either opening a locked or closing a trapped door) while he is in the door, he will be bounced out. However, the door still acts like a normal door, and so he may pass through it again. However, if when he passes through it there is another key there creating or opening a locked door and the normal door, he will bounce back again. This can be used to multiple effects, by alternating locked doors and trap doors over a normal door, effectively creating door propulsion that can be used multiple times.
This effect is used once in this map:
http://numa.notdot.net/map/63515
Every time the ninja hits a door, he activates one switch, propelling him upwards. Then he will fall back and hit the door and again, activating a switch until there are no more switches, at which point he falls through the door, because it is back to acting like a normal door.
Normal Door + Gold Delay
This propulsion works on the fact that a ninja can interact with a normal door, even if its just a small amount. If the right amount of gold is placed on the door (usually about 6 gold) then the ninja will be in the door when the last piece of gold is collected. For some unknown reason, the door shuts, pushing the ninja out. The velocity that the ninja is ejected out depends on where he is in the door when the last piece of gold is collected. Sometimes he is shot out slowly, other times he is shot out fast, and its possible for him to bounce off the door. Watch this map:
http://numa.notdot.net/map/51577
This map has examples of the ninja being speed up a little and a lot by doors. It also shows the ninjas direction being altered, sometimes just a little and sometimes a lot (completely in the other direction once) by doors. This method of propulsion also provides the ninja with protection, because the doors deter enemies.
Locked Door Glitch
The locked door glitch, like teleporters, requires code-editing. The code of a locked door looks like this:
9^708,588,0,0,29,21,1,0,0
To change it into a glitch door, change the third number after the ^ to an NAN. A glitched door is always vertical. When messing around with them they may seem random but there are general rules that apply to them:
A: This is what the door will always look like unless opened.
(N.B: A door will act like there is nothing there if it is opened)
B: This diagram comes as close as possible as I can represent how a glitched door acts. The red line is where the door appears to be, but in fact there is nothing there that interacts with the ninja. The one way doors represent the fact that you can only travel through them one way, however, unlike one way doors, they have corners that you can tilt off of. Finally the launch pads show which direction you will probably be launched in if you collide with that point, however the velocity at which they launch is seemingly random and depends on the speed and angle at which you collide with it. A lot of the time, the area will kill you, so careful testing is required to get the required launch. Also, an interesting point in terms of protection is that the visible door offers no protection, while the one way doors act like one way protection acting in the same direction as a normal one way door. For example:
In this diagram, both doors are glitched. The upper rocket cannot see the ninja because the upper door is protecting the ninja. The lower rocket and see the ninja and will fire, because the lower door only offers protection from above. For examples of all that have been explained above about glitched doors watch this map:
http://numa.notdot.net/map/55476
Thwumps
Thwumps are one of the most versatile objects that can be used in a DDA. In terms of propulsion, they can be used like tiles to change the ninjas velocity, they can be used to push the ninja and they can be used to expel the ninja at high-speed by squeezing him between itself (the thwump) and another object/tile. Even though thwumps are so versatile, they can be difficult to use because they (usually) move around, so they need to placed so that they move the ninja when wanted, and dont interact with the ninja (by death or otherwise) when unwanted. However, that said, it is possible to place a thwump inside a tile so that it doesnt move until the ninja gets in its activation range, and when the ninja does, it moves backwards forever, through tiles, and off the map:
In the diagram above, as long as there is any tile in the red area, the thwump will move in the direction of the arrow when activated. In the last two cases, a little more care is needed when placing the thwumps; they will not obey these specials rules if they are placed on ½ snap. The third thwump in the diagram must be placed exactly one pixel up from its ½ snap position to work. The last thwump must be placed exactly one pixel to the left of its ½ snap position to work. Both of these can be done by code-editing. The code of a thwump looks like this:
8^444,204,1
The first number after the ^ is its horizontal position, and must be reduced by one for the thwump to be able to move left. The second number is its vertical position and must be reduced by one for the thwump to travel upwards.
Firstly, the thwump moving the ninja like a tile is self explanatory. If the ninja collides with the thwump, it changes velocity, if it finds itself inside a thwump; it is expelled out with force. Secondly, if the ninja hits the right side of a retreating thwump, it is pushed along with the thwump. This can be used to push the ninja into objects, which then squeeze him out. To see examples of all of these watch this map:
http://numa.notdot.net/map/41973
The ninja is pushed and squeezed by thwumps, giving him the required motion to move around.
False Tiles