Christian Ochsner shares some insight into three file formats: OBJ, Collada and Alembic.
Christian writes:
I thought it might be helpful to some people to laern something about the new Alembic file-format and how it differs from OBJ and Collada, which is why I just wuickly wrote a short tutorial on that ;)
23 Comments
Yeah, the good ole question. I have been using my own format for like 17 years. Whenever I change my 3D editor I just write a new exporter and I don't really give a damn. Every 3D package has its very own format that the others (of course) do not support. Srsly why bother lol...
So he hates OBJ. It is still the world’s simplest 3D format, and probably the widest-supported too. Being text-based, it is almost child’s play to whip up quick-and-dirty scripts to do massaging of OBJ files.
Ultimately, OBJ is the one reliable common denominator; other formats may work and be more efficient, but if they don’t work, then you always have the fallback of OBJ.
It would be great if there was an equivalent for animations. Regularly running into issues when trying to integrate work from non-blender based animators
dot-blend...I never leave blender anymore....I'm being serious, I used to jump into silo or LW and even trueSpace, but now I stay in blender 100%.....so for me file formats are non essential....I hope that one day every other package is more interested in the blender file format....enough blender worship...back to blending.
Hmm, the opinion of an 18 year old who wants to study history and philosophy AFTER graduation. For the next article can we get someone with real industry background and credible experience?
Lets hear. What would be wrong with studying history or philosophy after graduation?
Read between the lines. If the authors bio stated something like "CG enthusiast who wishes to pursue a career in film or CG after graduation" then you would at least know you are reading an article by someone with a passion that correlates with the article's contents. And I would agree that articles based on test cases by someone with some sort of proven experience would have been a more worthwhile read. This blog offers nothing and it seems some of us feel it's not even a worthwhile post for BN. The author has all the freedom in the world to write what he wants but the quality of content that gets posted on BN could use some better filtering.
Good point. I'll be more critical next time.
Now wait a minute. Just because he's not majoring in CG doesn't mean he doesn't like it or enjoys it as a hobby. For example, I'm currently majoring in Recording Arts (audio stuff) and then I'm doing stuff in the IT department, but I still love CG and 3D animation very much. Does this now mean that my opinion doesn't matter as well?
What you love and what you have sound knowledge and experience with are 2 different things. I love driving sports cars but since I know little about cars my opinion on the underlying mechanics of a good transmission or engine would be relatively useless.
Is it more worthwhile to save meshes in Collada or Obj?
If it's a simple mesh that doesn't move, then OBJ should be just fine.
Also the author of the article failed to mention that Collada has a bunch of problems becuse there are MANY types of collada files. DAZ has their version while Autodesk has their version... and I think CryEngine has its own version as well... so Collada actually has subformats. Hopefully Alimbic won't. OBJ doesn't... and he forgot to mention FBX which is most likely used more than Collada... well I use it more anyhow.
Is it fair to say, then, that Collada is like the TIFF of 3D file formats?
I am looking forward to learn this . I know how to export but I am sure ,so much more to it .
I thought at first several other people in the comments here were being mean (as often happens here on Blendernation). But yeah, this guy doesn't really seem to know what he's talking about.
As far as I know, Collada files are only smaller because they use compression (this is from my experience in Google Sketchup - I don't know if this is the norm), but the internal textual structure (which he states in XML - I'm taking his word for it) is probably MUCH larger than that of obj - since there's extra space taken up by the XML tags.
This makes Collada LESS efficient - you can always compress an obj file if you really want to, but for reading in, decompressing, and then parsing, I'm pretty sure .obj would actually perform better than Collada (based on the information in the article - I too am far from an expert).
Whats more, is he says "the implementation is not being that good" for Alembic. To me, a bad implementation means slow, inefficient, bloated, and so forth - and my first thoughts are that it sounds TERRIBLE to use at all for this reason. But when you read it a bit more, it sounds more like he's saying it doesn't yet have much SUPPORT among popular 3D applications - an issue that is very different than having a bad implementation (in my own interpretation of the words 'implementation' and 'support', that is).
Sorry that I didnt make it clear enough what I meant by "implementation" - of course I mean support! I updated the article. Concerning the rest of your critique, I can only say that I always made the experience that COLLADA was a lot faster, I never tried to compress OB, but I see your point. However, this is just a theoretical approach, these are just your thoughts and dont have the impression that you tried it. I might do a research on this next week.
Something I want to make clear: I do NOT consider myself to be an absolute expert, I am sharing my experiences on my blog, these might comply with anybody elses, or they might not. What I write on my blog is not be seen as THE way of doing things, it is just my opinion and although I am not directly after a career in VFX, I am serious about it as a hobby.
It's... Kinda littered with spelling and grammar mistakes.
When exporting from sketchup Pro I find the OBJ format is reliable. I get meshes and materials. It is ready to render with Blender Internal. I just have to replace the glass material in Cycles and it looks great. This is an architectural rendering of two city blocks I am currently doing. The file exports as a 10MB .OBJ file that loads into Blender in 3 seconds. I tried Collada, the file was 38.6MB and crashed Blender when I loaded it. I tried .DXF and the file was 69.5MB and Blender messes up the mesh. Result = OBJ is the true work horse. It makes a smaller file and loads with no problems.
I don't know.
I mean I've listened to the 13 minutes vid on his linked page and I must say that if and I do say IF all that is said about Alambic is true. maybe Ton Roussendall (sorry if its misspelled) should at least consider it. Colada seam to be a hassle to implement and make it work for all the softs related to 3D. (remember that Blender itself almost lost the colada imp/exporter not so long ago). Anyway...
I think that based on what I saw on the above mentioned vid, Alambic could be a great import/export option specially if .obj is way bigger in terms of file saving and way slower in terms of import/export. (see video)
-TheElwolf
How to convert .IGES to .OBJ with nice tweaking options? Who knows? I found only MoI - it's good but costs too much to be just a fine converter.
BTW, I like that optimistic point about Alembic b'coz the world of CG isn't stopping so something must become a start for the new generation of inter-program file formats (or one that is definitely better :) )
all of them are crap inconsistencies all along all of the formats its all a bloody mess
they are even not compatible with older versions of the same format (collada) and each friggin environment interprets each format to its own liking not their schema description , even importing the same work exported by the same damn environment you'll be surprised with errors conflicts wrong assets association
maybe the industry needs a person with an IQ of a more than 2 digits to put a solid standard (who am i kidding) , not in this life i am sure
meh....
the link doesn't work anymore