Adriano Gil adrianogil

Unity hotswapping notes

Unity has built-in support for hotswapping, which is a huge productivity booster. This feature works not only with graphics assets like bitmaps and meshes, but also with code: if you edit the source and save it, the editor will save the state of the running game, compile and load the new code, then load the saved state and continue where it left off. Unfortunately, this feature is very easy to break, and most available 3rd party plugins have little regard for it.

It looks like there’s a lot of confusion about hotswapping in Unity, and many developers are not even aware of its existence – which is no wonder if their only experience is seeing lots of errors on the console when they forget to stop the game before recompiling... This document is an attempt to clear up some of this confusion.

Nota bene, I’m not a Unity developer, so everything below is based on blog posts and experimentation. Corrections are most welcome!

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	<head>
	<title>Graphics, Games, Programming, and Physics Blogs</title>
	</head>
	<body>
	<outline text="Tech News" title="Tech News">
	<outline type="rss" text="Ars Technica" title="Ars Technica" xmlUrl="http://feeds.arstechnica.com/arstechnica/index/" htmlUrl="https://arstechnica.com"/>
	<outline type="rss" text="Polygon - Full" title="Polygon - Full" xmlUrl="http://www.polygon.com/rss/index.xml" htmlUrl="https://www.polygon.com/"/>
	<outline type="rss" text="Road to VR" title="Road to VR" xmlUrl="http://www.roadtovr.com/feed" htmlUrl="https://www.roadtovr.com"/>

	/*
	A simple little editor extension to copy and paste all components
	Help from http://answers.unity3d.com/questions/541045/copy-all-components-from-one-character-to-another.html

	license: WTFPL (http://www.wtfpl.net/)
	author: aeroson
	*/

	using UnityEngine;
	using UnityEditor;

	pete@balloon:~/projects/nand2tetris/phiggins/01$ pwd
	/home/pete/projects/nand2tetris/phiggins/01
	pete@balloon:~/projects/nand2tetris/phiggins/01$ ../../tools/HardwareSimulator.sh ~/projects/nand2tetris/phiggins/01/Mux4Way16.tst
	End of script - Comparison ended successfully
	pete@balloon:~/projects/nand2tetris/phiggins/01$

	using UnityEngine;
	using UnityEditor;
	using System;
	using System.Xml.Linq;
	using System.Collections.Generic;

	public enum MapType {
	Isometric,
	Orthogonal
	}

	"""
	MIT License

	Copyright (c) 2017 Cyrille Rossant

	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is

	This is free and unencumbered software released into the public domain.

	Anyone is free to copy, modify, publish, use, compile, sell, or
	distribute this software, either in source code form or as a compiled
	binary, for any purpose, commercial or non-commercial, and by any
	means.

	In jurisdictions that recognize copyright laws, the author or authors
	of this software dedicate any and all copyright interest in the
	software to the public domain. We make this dedication for the benefit

	// C# example
	using UnityEditor;
	using System.IO;
	using System.Collections;
	using UnityEngine;
	using System.Collections.Generic;

	class PerformBuild
	{
	static string[] GetBuildScenes()

	#!/usr/bin/python
	import subprocess
	import re
	import os
	import sys
	import optparse
	import time

	def call_checked(*args):
	r = subprocess.call(args)

Adriano Gil adrianogil

Unity hotswapping notes

The basic flow of hotswapping