Unity 4 to 3 project converter?

Unity Engine
1

Hi there was wondering if Unity had a project conversion utility, that would take a Unity4 project files and convert them to be ‘compatible’ with Unity3.

I realise that this would still leave a few things broken, e.g. links or features not supported in 3 but it would be a great help to developers who have a play with 4 then want or need to take the project back to 3.

However if there is not one does Unity have any documentation that would allow the community to make one, file formats ect?

2

There is a simple solution. Its called a backup. You need to keep a copy of your project in 3.5 and if you don’t like 4 then go back that un-upgraded project using 3.5. Problem fixed ! So always keep at least a copy of your project.

3

Yes Yes, but say you have worked on your project for a couple of days or so in 3.5, a new version of 4.x rolls out you download it and decide to test it woops, you select your current version, no backup so a that’s a few days work just gone.

Or you just decide to have a play with 4.0 and wow a fun little game develops, then you spend more time on it and hay this is great. OMG it’s in 4.0 and I don’t have $$$$ to buy a license but I have a license for 3.x all that work gone to waste.

This is not rocket science it’s just file type conversion, taking files and data with one format and converting it to a new set of files with a different format.

4

I don’t get that logic. Why would someone start a game in 4 when they have the pro 3.5 but the free Version 4 ?

I’m just questioning how useful this really is. How hard can it be to duplicate your project or backup before you upgrade to a newer version of Unity I wonder ? I’m pretty sure its much faster and less trouble than to write a tool that will do a backwards compatibility conversion.

Just change your habits and before you upgrade Unity, always back-up and you will never need such tool.

Now if you are stuck with a project in 4 and needed 3.5 well I guess you could use export/import package. If you are organized in your work and know the files you worked on, it should not be that hard to salvage the things you worked on the last couple of days in 4 and bring them to the 3.5 project.

Anyways, my opinion on the matter is the following: By not having a copy of your recent project before upgrading you are taking a risk of breaking your project. If you can take such risks, it means your project is not that important to you. And if you really care, then take it as a lesson and from now on always have a copy before upgrading.

Prevention is better than cure.

5
  1. Why don’t you have a backup? It’s completely irresponsible not to. 2) Unity tells you when you’re about to upgrade a 3.x project to 4.x and gives you a chance to stop, so you would have to intentionally ignore this warning. Also Unity 3 and 4 have completely separate preferences and settings, so your Unity 3 projects won’t even show up in the Unity 4 project wizard.

If it were that easy then someone probably would have done it by now, yes? :wink:

Nope, Unity 3 won’t load a Unity 4 package.

–Eric

6

I think there should be such a tool or method to do this. If like myself you have 3.5.7 pro and cant afford to upgrade, then need an asset on the store marked as 4 plus only even though it uses none of 4’s extra functionality, you could at least have a side by side unity installation with 4 to buy the package and install it.

Personally id rather see a unity tool that repairs broken projects when unity messes them up. Lost 2 days work last week cos of this.

7

Thanks for the info !

8

@arkon thanks for the support!

Exactly they already have, Unity 4 loads Unity 3 file types the converts them to Unity 4 file types.
All we need is that file conversion path to run the other way?

Arguing about how to avoid it is like arguing over spilt milk, the focus should be on providing a way to solve the current problem and clean up the mess.

9

folks - i’ve just encountered a situation similar to this. i’m working as a subcontractor of interactive examples to a dev, and they provided me a basic template and directions to integrate my examples with their code. somehow it was not made clear to me that they were using 3.5.7 and i’m now on 4.1.2. i started all of these projects in version 4, seeing as how it’s been out now for a while, and should be past the ‘bleeding edge’ stage i’d think.

so now i have to see whether these projects built in version 4.1 can work at all in 3.5.7. i guess we should have had better communication on this, but that’s a situation which no amount of backups could have solved. so now that i’m in this situation, anyone have any tips or helpful links or such geared towards backporting to 3.5.7? would be immensely appreciated.

best,
scott