Arcadia Community Procjam Entry
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  • use the 2017.1.0 version of Unity if possible
  • git clone --recursive or clone Arcadia into Assets


  • Joseph Parker - GitHub selfsame
  • Douglas P. Fields, Jr. - GitHub LispEngineer
  • Joshua Suskalo - GitHub IGJoshua
  • Ramsey Nasser - Github nasser
  • Tims Gardner - Github timsgardener


Our entites are collections of parts, which are defined like:

(use 'game.entity)

(part {
  :type :body
  :id :business
  :prefab :parts/business-body
  :hp 1
  :power 0
  :mount-points {
    :neck {:head 1}
    :left-arm {:arm 1}
    :right-arm {:arm 1}} 
  :hooks {:update (fn [root entity])}
  :state {:foo 1}
  :ai (behaviour [o]
  		(wait 1)
  		(fire o)
  		(AND (aim o)
             (wait 1))
        (end-fire o))})
  • :type user taxonomy, :mount-points declare which types they allow. value can be a keyword or collection of keywords for multiple type registration
  • :id optional, helps with redefining parts without registering duplicates
  • :prefab corresponds to a prefab on a path within Assets/Resources
  • :hp part's contribution to total entity :hp state, default is 1
  • :power contribution to total entity difficulty, (should only be used with weapons), default is 0
  • :mount-points keys should match names of gameobjects in the part, vals are a probability map of which type is chosen. Note you can have a chance of no part ({nil 10})
  • :hooks are a map of functions that will be routed from the root entity. The first arg is the root object, second is the part object. You may want to use a var if you plan on re-evaluating the function at runtime.
  • :state will be placed into the part state by the :procjam/part key
  • :ai function that returns a collection of tween.core/timeline style functions. Recommended to use the behaviour macro, for more details see the AI section below.

Parts will match the rotation of their mount point transform. Our convention is Z+ is forward and Y+ is up, where an arm should extend along the Z+ axis.

Part meshes that use the SKIN material will have a color assigned. If your blend is saved in Assets/blends, you can just name a material "SKIN".

project structure

  • game.core sets up the game loop
  • constructs game maps
  • game.entity assembles parts into entities
  • ns with no deps for global stuff
  • game system functions (damage/kill), generic part hooks
  • composable behaviour functions
  • game.fx special effect fns

part definitions can go in user namespaces like selfsame.clj


Entity AI is described as timeline state machines (see Parts can contribute sequences via an :ai entry, which are concatenated and cycled through.

The :ai value should be a function that returns a collection of double wrapped functions (due to using timeline-1).

(part {
 :type :brain
 :ai (fn [root] 
       [(fn [] #(log "tick"))
        (fn [] (wait 1))])})

The macro makes this a bit sleeker:

(part {
 :type :brain
 :ai (behaviour [o]
	   #(log "tick")
	    (wait 1))})

It's recommended to read through the timeline docs and before designing behaviour sequences.

Here's a rundown of the default behavior:

(wait (?f 1))

;truthy while the player is far away, so the timeline parks here
(NOT (player-in-range? o 40))

; charge is always truthy, so we compose with a wait
; we also move on if the player is close enough
(AND (charge o)
     (NOT (player-in-range? o 6))
     (wait (?f 0.3 1.5)))

; due to our input model, we need to clear the :movement
; that was turned on during `charge`
(stop o)

; turn on :fire button
(fire o)

; aim is always truthy
(AND (aim o)
     (wait (?f 0.5 2.0)))

(end-fire o)

; falsey, sets :movement
(wander o)

; spend some time walking
(wait (?f 0.5 1.0))

; compose strafe and aim (both truthy)
(AND (strafe o (rand-nth [-1 1]))
     (aim o)
     (wait (?f 0.5 2.0)))

(stop o)