notes

TODO: go through all BJS material handling and set checkOnlyOnce, markDirty, etc. 

	* Add a "player crossed a chunk border" event


camera and movement after latest changes:
	rendering processors:
		physics - set backtracked renderPositions from physics data
		followsEntity - copy entity's renderPosition from followed target
		mesh - move meshes to render positions
	rendering function:
		updateCamera
			copy camera target pos/rot to cameraHolder mesh
			tween camera position (inside camera holder) towards capped position
			check if camera is now inside solid block
				if so, check obstructions
					set cam offset and cap distance
				move camera to cap
		acutal render
		

		

TODO
	make physics engine handle bodies that don't collide with terrain
	make terrain component aware of this
	
	Later: need to rework camera to just be a free camera that looksAt() stuff?
	.. in order to have a follow camera with a target offset from player mesh




Movement
	entity movement component
		heading, runspeed, stopspeed, jumpHeight, etc.
	input receiving component processor
		set player entity's heading from camera direction
		set isRunning, isJumping, etc. from inputs
	mob AI processor (plays same role as input, but from AI)
		set mob entity heading, isRunning, etc. based on AI rules
	movement processor
		apply forces in direction of heading
		handle world collisions, friction, autostep, etc.
	on RENDER
		update mesh positions to body.position + velocity/dt



Function injection:
	window._ct = 0
	var q = function(x,y,z) { this.x=x, this.y=y, this.z=z; window._ct++ }
	q.prototype = BABYLON.Vector3.prototype
	for (var s in BABYLON.Vector3) { q[s] = BABYLON.Vector3[s] }
	BABYLON.Vector3 = q