Footprint: Difference between revisions

In [[Bloons TD 6|''Bloons TD 6'']], the majority of towers, [[Power|powers]] and other items that can be placed on the map have a circular footprint, with a few exceptions, listed on the table below. Despite all towers having an internal "footprint radius" defined (or height and width for rectangular forms), they have separate flags that determine their behavior, as they can block other tower placements, which this is true for the vast majority of towers, however some sub-towers do not have this flag active like [[Sentry Gun (BTD6)|Engineer Sentries]] or Mini-Sun Avatars. This is also true for powers like [[Pontoon (BTD6)|Pontoons]] and [[Portable Lake (BTD6)|Portable Lakes]] and the footprint is used instead to determine the amount of available space for other towers that are placed over them.

|Beast Handler's [[Gyrfalcon]] and higher upgrades.

Sub-towers (Ball of Light, [[Summon Phoenix (BTD6)|Phoenix]] (including upgrades), [[Bottle of 'Gerry's Fire' Hot Sauce|Hot Sauce creature]], Nature's Ward totem, Spirit form [[Dark Dungeons]], UAV, UCAV)

|[[Genie Bottle]], planes from [[Sun Temple (BTD6)|Sun Temple]] or [[True Sun God (BTD6)|True Sun God]]

|[[Sentry Gun (BTD6)|Engineer Sentries]], including Paragon Sentries from [[Master Builder]] and their children

|[[Banana Farmer (BTD6)|Banana Farmer]], [[Tech Bot (BTD6)|Tech Bot]], [[Energizing Totem]], [[Special Poperations (BTD6)|Monkey Marine]]

|[[Dart Monkey (BTD6)|Dart Monkey]], [[Tack Shooter (BTD6)|Tack Shooter]], [[Ice Monkey (BTD6)|Ice Monkey]], [[Glue Gunner (BTD6)|Glue Gunner]], [[Sniper Monkey (BTD6)|Sniper Monkey]], [[Ninja Monkey (BTD6)|Ninja Monkey]], [[Alchemist (BTD6)|Alchemist]], [[Rosalia (BTD6)|Rosalia]]

Sub-towers (Planes from [[Aircraft Carrier (BTD6)|Aircraft Carrier]] and higher upgrades, Etienne's Drones, Sacrificial Totem, Mini-Sun Avatar)

|[[Boomerang Monkey (BTD6)|Boomerang Monkey]], [[Desperado (BTD6)|Desperado]], [[Bomb Shooter (BTD6)|Bomb Shooter]], [[Monkey Sub (BTD6)|Monkey Sub]], [[Dartling Gunner (BTD6)|Dartling Gunner]], [[Wizard Monkey (BTD6)|Wizard Monkey]], [[Druid (BTD6)|Druid]], [[Engineer Monkey (BTD6)|Engineer Monkey]], [[Beast Handler (BTD6)|Beast Handler]], [[Cave Monkey]], [[Battle Cat!]], All Heroes (Except Rosalia, Captain Churchill, Pat Fusty)

|[[Monkey Buccaneer (BTD6)|Monkey Buccaneer]], [[Mermonkey (BTD6)|Mermonkey]], [[Spike Factory (BTD6)|Spike Factory]], [[Captain Churchill (BTD6)|Captain Churchill]], [[Pat Fusty (BTD6)|Pat Fusty]], trance totem from The Final Harmonic.

|[[Monkey Village (BTD6)|Monkey Village]], [[Mortar Monkey (BTD6)|Mortar Monkey]], [[Super Monkey (BTD6)|Super Monkey]]

|[[Portable Lake (BTD6)|Portable Lake]]

|[[Monkey Ace (BTD6)|Monkey Ace]]

|Rosalia's base, [[Pontoon (BTD6)|Pontoon]]

|[[Heli Pilot (BTD6)|Heli Pilot]]

|[[Banana Farm (BTD6)|Banana Farm]]

|[[Sun Temple (BTD6)|Sun Temple]], [[True Sun God (BTD6)|True Sun God]], [[VTSG]]

The air unit of towers that are linked to a base (Heli Pilots, Monkey Aces and Rosalia) technically do not have a footprint but in Rosalia's case it does create a placement block of 6 units which acts as a footprint, which is removed when she reaches level 7. However, the planes from a Sun Temple of True Sun God are treated as sub-towers and not as air units, and they have a footprint with a radius of 1 unit, which is located in the same place as their parent tower (it can be seen in the image above by zooming into the Super Monkeys).

Towers and Heroes do not change their footprint when they are upgraded, even if the model is visually larger, which is specially evident on [[Paragon|Paragons]], however, this behavior has one exception, which is when a [[Sun Avatar (BTD6)|Sun Avatar]] is upgraded into a [[Sun Temple (BTD6)|Sun Temple]], in this case the footprint grows from a radius of 8 units to a rectangle with a width of 37 units and a height of 40 units. This usually does not have any interactions with other regular towers as they are sacrificed when the upgrade is purchased, however as the Sun Temple cannot sacrifice Powers or Heroes, if they are placed right next to the Super Monkey before being upgraded, they will end up inside of the Sun Temple's footprint, this interaction does not impact the towers and can bet moved away by using the Redeployment ability of a [[Support Chinook (BTD6)|Support Chinook]],

This behavior can is used used on [[Freeplay]] strategies to save space for [[Tech Bot (BTD6)|Tech Bots]] by placing them around Super Monkeys that are intended to become Sun Temples later in the game. Also, there is a small window of time after purchasing the Sun Temple where after the Monkeys around it are sacrificed but before its footprint grows, this can be exploited by using a Support Chinook to move a tower right next to the Sun Avatar during the transform animation so it ends inside the Temple's footprint.

Optimal placements of towers with the same or different sizes within a certain area is a common problem that is found in recreational mathematics, known as [[wikipedia:Circle packing|circle packing]], and despite the intuition of going for hexagonal or triangular patterns (where the form indicates the arrangement of the center of the circles) are usually not the [[wikipedia:Circle packing in a square|optimal solution]]. Although [https://www.sciencedirect.com/science/article/abs/pii/S0305054812001141 procedures exist] for regular forms, the variety of shapes of open areas in maps in ''BTD6'' makes finding optimal solution it a difficult task that usually can only be solved a brute force trial and error approach.

{{empty}}