The debate about how Blender will deal with the lack of support and activity from the open source Collada crew is still up in the air. Fortunately for Second Life residents there is a fix available. It comes to us from Gaia Clary in the form of a free Python script. So… here is the story.
Hopefully you know Collada is the file format used by Second Life for import of 3D models made in various 3D modeling programs.
What many don’t know is the Collada open source project is not very active. It has great ideals and is arguably the current the best model import/export plan for transferring models between various modeling programs and games. But, there is not a lot of work going on in that open source group.
First, it looks to me like Blender.org will move the integrated Collada export/import feature to a branch off of the main Blender development trunk. This means the Collada feature will likely disappear from the next release of Blender. At the best the current, lame, partially working feature may be left in future releases. But, again that is undecided and things are changing daily.
There are some gatchas in the Collada export/import feature that affect those working with rigged mesh in Second Life. Collada is one of the few formats that deals with rigged mesh. But, it has some problems. Add to Collada’s problems the special needs of the Second Life import feature and those making clothes and avatars have lots of problems.
Which bones are used, the number of textures in each layer of the model, bone rotations, and differences between the Blender and SL orientations of the model all contribute to often not being able to import a model. This plug-in is targeted at fixing that.
The obvious solution is to fix Collada in Blender. But, the politics of open source are going to make that a slow process. The Lab doesn’t have Blender coding experts, so it is unlikely they will be able to fix it. They might be able to throw some money at it, if there were someone to throw toward.
It may be some time before Blender itself is fixed.
Gaia Clary of Machinimatrix.org came to the rescue. A Python script for Collada export was developed for use with their Avastar product. The plug-in has been made available to the community for free.
Download the Collada Exporter for 2.59, 2.60, and 2.61. Donations are probably appreciated.
Installing Collada Exporter
I have some concerns about how Blender will develop in the future. Some of the Blender peeps think a Python script is not going to work. I understand their issues about Blender having to provide hooks for Python Collada. Python works now. So, their concern is confusing. Whether moving Collada to a branch will break the Python or whether newer versions will break it, I just don’t know.
I do know that I have several Blender Python scripts/plug-ins that only work with specific versions of Blender. Whether this Collada exporter script will fall into that group I don’t know. But, I would rather be creating than figuring out how to get Blender to work with every update. For that reason I suggest that one use the Archive Install rather than the main install program. that method allows yu to have several working versions of Blender installed, each with their unique configuration and batch of plug-ins.
I’ve written about the process several times. So, I’ll only link to it. See: Blender 2.61 Released.
Dealing with Plug-ins
Blender updates often, which is good. But, it makes for a hassle installing the plug-ins I use. With each update I have to run down my set of plug-ins and install them to the new version of Blender. To make my life easier I download all the plug-ins to a Blender Plug-in folder I made. I put it in my folder for Blender downloads.
In Blender I navigate to that folder and install from there. I also add the folder to bookmarks in Blender. Open the file open dialog to see bookmarks or to add to them. You can also create a bookmark when you install this Collada plug-in.
Gaia has the steps for a simple quick install of the scrip. I’ll give you a step-by-step that is a little more explanatory and has more tips.
First you have to get the script: Download the Collada Exporter. It is a tiny file. Put it in a folder you use to store Blender plug-ins.
Open Blender in default mode… meaning do NOT open an existing file. I customize Blender to the way I like to work. Mine opens without the standard cube and with windows arranged the way I want them. One has to update this ‘default’ setup when adding plug-ins. Otherwise; you must activate the plug-in each time you want to use it. So, get Blender just the way you want it because that is how it will look next time you open Blender.
To install the plug-ing click FILE in the top menu. Next find User Preferences and click it. Or just press Ctrl-Alt-U from the main Blender window.
At the bottom of the panel look for Install Addon… and click it. A file open dialog appears. Navigate to the plug-in. Once there click ADD at the left to bookmark the plug-in folder, if you want. Then click on SLCollada-1-8.py and then Install Addon… in the upper right.
Once installed, you will be back to User Preferences. Now activate the new plug-in by clicking the checkbox in the right of the plug-in entry.
If you click the white triangle to the left the plug-in information will expand. In that information is the menu path you need to use a plug-in. In this case it is intuitive. But, it is handy to know this menu path information is there.
The last step is to click Save As Default. This will change your basic default settings to use what you have now. It will remember the plug-in is activated.
That’s it. You can now open a model and export it.
Help & Discussion
Gaia announced the release of the exporter in the SL Forum in: SL Collada 1.8 for Blender. Stop by and at least say thanks.
Also, be sure to read the usage instructions on the download page.
If you run into problems with the exporter, bring them up there.