Added spit draft of FirstPersonPlayer modifier

assets/system/first_person_player.modifier.wren

@@ -0,0 +1,88 @@
+import "fpkit: system/first_person_player.modifier.api" for API, Modifier, APIGet, APISet, Wire, Fields, State, Op
+import "luxe: io" for IO
+import "luxe: assets" for Strings
+import "luxe: world" for Entity, World, Transform
+import "luxe.project/asset" for Asset
+import "luxe: math" for Math
+import "luxe: system/physics/physics3D.modifier" for Phyiscs3D
+import "luxe: system/physics/character3D.modifier" for Character3D
+
+#block = data
+class Data {
+	var camera: Link
+
+	var acceleration: Num = 0.6
+	var decelleration: Num = 0.6
+	var ground_check_dist: Num = 0.15
+
+	var jump_impulse: Num = 2.25
+	var jump_force: Num = 1.0
+	var jump_force_falloff: Num = 0.3
+
+	#hidden
+	var is_grounded: Bool = false
+
+	#hidden
+	var target_input: Float3 = [0, 0, 0]
+}
+
+#api
+#display = "First-Person Player"
+#desc = "**A new modifier**. You should update this description" 
+#icon = "luxe: image/modifier/modifier.svg"
+class FirstPersonPlayer is API {
+	//add public facing API here
+}
+
+#system
+#phase(on, tick)
+class System is Modifier {
+
+	//required atm
+	construct new(world: World) { super(world) }
+
+	init(world: World) {
+		_world = world
+		Log.print("init `%(This)` in world `%(world)`")
+		Physics3D.create_in(world)
+	}
+
+	#hidden
+	attach(entity: Entity, data: Data) {
+		Log.print("attached to `%(Strings.get(Entity.get_name(entity)))` `%(entity)` - `%(This)`")
+
+		if (data.camera == null) {
+			data.camera = Entity.get_named(world, "app.camera")
+		}
+	}
+
+	#hidden
+	tick(delta: Num) {
+		var fore = Input.event_active("up", "game") ? -1 : 0
+		var back = Input.event_active("down", "game") ? 1 : 0
+		var left = Input.event_active("left", "game") ? -1 : 0
+		var right = Input.event_active("right", "game") ? 1 : 0
+
+		each {|entity: Entity, data: Data|
+			if (data.camera == null) return
+			if (!Character3D.has(entity)) return
+
+			target_input = Transform.local_vector_to_world(data.camera, right + left, 0, fore + back)
+			target_input.y = 0
+			Math.normalize(target_input)
+			target_input.y = Input.event_began("jump", "game") && data.is_grounded ? data.jump_impulse : 0
+
+			Character3D.set.input(entity, input)
+		}
+	}
+
+	check_if_grounded(player: Entity, data: Data): Bool {
+		var half_height: Num = Character3D.get.height(player) * 0.5
+		var padding: Num = Character3D.get.character_padding(player)
+		var dist = half_height + padding + data.ground_check_dist
+
+		var result = Physics3D.cast_ray_closest(_world, Transform.get_pos_world(player), [0,-1,0], dist)
+
+		return result != null
+	}
+}