[WF-Protocols] A few remarks from the Blender frontier

[Ton Roosendaal]

Hi all,

I've been invited by Aglanor to participate in the discussion on the  
proposed Open 3D Model Format. Although such discussions always  
interest me, I'm tied to Blender releated projects too much to be  
available for regular contributions. :)

Neverheless, it is good to be able to synchronize development, and  
ensure that 3d open source projects really integrate and cooperate  
well. Blender itself is still far from that desired goal, but a few sub  
projects have started at blender.org that might be of interest for you  
on this topic:

- BlendXML format
A team is working on conversion of our mysterious .blend format into a  
readable XML version. They aim at making it 100% compatible, so that it  
can exist next to our binary format as a valid option to save/read your  
work. Aim is to create a good interchangable format, compatible with  
X3D as much as possible. The project is still in development, results  
have not been reviewed yet. The authors of this project promised  
something within the next weeks.
http://projects.blender.org/projects/blendxml/

- reconstructed Python API
Yesterday a test release was done with the completely rewritten Python  
API in Blender. The old code was a complete mess... the current code is  
nicely formatted & documented, and ready for further development,  
including sophisticated importers/exporters.

Most likely, when this mailing list results in consensis on a new 3d  
exchange format, it is technically well possible for developers to make  
sure Blender can read/write it as well. I can promise to promote &  
stimulate such a project here.

Then on the exchange format topic itself;

- At the web page about this format (and in the threads after july 1  
here), I miss an analysis of the problem definition. Typically  
something you do before pinning down the functional specification,  
which seems to be the discussion topic already. Maybe I've missed it,  
but it's very interesting to know. Have existing formats been rejected,  
like X3d or so? The mentioned objective: "to define a free, extensible  
3D model format standard... etc" is general, but the rest of the page  
mostly mentions game engines as being the focus.

- I have an Amiga background (sweet 80ies!) and quite familiar with  
IFF. The binary .blend format has been derived from it, but extended  
with a header with information about the actual data that's in the  
chunk. Each header has an pointer to a designated 'structure DNA'  
chunk, describing the types & names of the chunk contents. This enables  
quick reading/writing, plus keeps internal structure changes  
forward/backward compatible, as would an ascii format do.
Don't know if this method should get a following, it was nasty to code!  
But we've been using it in Blender since '95 with good (user)  
satisfaction. In theory it's possible to make a 1:1 lossless conversion  
of XML<->binary with such a system.

- My suggestion for you would be to adopt XML for the format, and try  
to be as close as possible to X3d... although I haven't evaluated X3d  
myself, the web3d consortium seems to have learned from the VRML  
failure.

- My suggestion for you also is to stick as closely as possible to the  
requirements for game engines, your core products. Setting an 'industry  
standard' can't be the goal, isn't it?

Good luck, hope this information is of any help!

-Ton-


------------------------------------------------------------------------ 
--
Ton Roosendaal  Blender Foundation ton at blender.org  
http://www.blender.org