godot/demos/3d/platformer/follow_camera.gd

extends Camera

# member variables here, example:
# var a=2
# var b="textvar"

var collision_exception=[]
export var min_distance=0.5
export var max_distance=4.0
export var angle_v_adjust=0.0
export var autoturn_ray_aperture=25
export var autoturn_speed=50
var max_height = 2.0
var min_height = 0

func _fixed_process(dt):
	var target  = get_parent().get_global_transform().origin
	var pos = get_global_transform().origin
	var up = Vector3(0,1,0)
	
	var delta = pos - target
	
	#regular delta follow
	
	#check ranges
	
	if (delta.length() < min_distance):
		delta = delta.normalized() * min_distance
	elif (delta.length() > max_distance):
		delta = delta.normalized() * max_distance
	
	#check upper and lower height
	if ( delta.y > max_height):
		delta.y = max_height
	if ( delta.y < min_height):
		delta.y = min_height
		
	#check autoturn
	
	var ds = PhysicsServer.space_get_direct_state( get_world().get_space() )
	
	
	var col_left = ds.intersect_ray(target,target+Matrix3(up,deg2rad(autoturn_ray_aperture)).xform(delta),collision_exception)
	var col = ds.intersect_ray(target,target,collision_exception)
	var col_right = ds.intersect_ray(target,target+Matrix3(up,deg2rad(-autoturn_ray_aperture)).xform(delta),collision_exception)
	
	if (!col.empty()):
		#if main ray was occluded, get camera closer, this is the worst case scenario
		delta = col.position - target	
	elif (!col_left.empty() and col_right.empty()):
		#if only left ray is occluded, turn the camera around to the right
		delta = Matrix3(up,deg2rad(-dt*autoturn_speed)).xform(delta)
	elif (col_left.empty() and !col_right.empty()):
		#if only right ray is occluded, turn the camera around to the left
		delta = Matrix3(up,deg2rad(dt*autoturn_speed)).xform(delta)
	else:
		#do nothing otherwise, left and right are occluded but center is not, so do not autoturn
		pass
	
	#apply lookat
	pos = target + delta
	
	look_at_from_pos(pos,target,up)
	
	#turn a little up or down
	var t = get_transform()
	t.basis = Matrix3(t.basis[0],deg2rad(angle_v_adjust)) * t.basis
	set_transform(t)
	
	

func _ready():

#find collision exceptions for ray
	var node = self
	while(node):
		if (node extends RigidBody):
			collision_exception.append(node.get_rid())
			break
		else:
			node=node.get_parent()
	# Initalization here
	set_fixed_process(true)
	#this detaches the camera transform from the parent spatial node
	set_as_toplevel(true)