If several people are "working on the same scene", they can be expected to divide the tasks between themselves in ways that require only exchanging files every now and then, like taking turns at editing the same files (perhaps with multiple shifts spread into different timezones) or working each on separate parts that are later combined.
You can come up with additional collaboration structures to do things, that is always possible, but not having to create additional structures gives one freedom to operate in any way you feel like. Google Docs technically isn't needed given that there is LibreOffice, but people still prefer Google Docs for its extreme convenience.
In the unusual case of real-time collaboration at 3D modeling tasks, I "imagine" one person actually doing the modeling and the others watching, commenting and directing. You can do this in person or with generic screen-sharing, chat and telephone tools, without interfering with concurrent editing.
Clara.io is intended to be a platform for modeling, animation, layout, tweaking, texturing, lighting, rendering and simulation, rather than just modelling. You are correct that there are many ways to achieve things and you will still be able to use screen-sharing, chat and telephone tools with Clara.io of course.
There are a number of rendering server farm services, and they obviously try to be open and support as many renderers and input file formats as they can. Are you tying your cloud-based modeling and your cloud-based rendering to each other through proprietary file formats, restricted data access, etc.? If not, why are you developing two products at the same time?
We just have a "render" button that works for Clara.io scenes. It is pretty simple. Why make things complex? If you want to export to another DCC package for lighting and rendering you are free too.
I have some experience with render managers as back in the early 2000s I wrote a product called Deadline (which you likely haven't heard of but it is quite popular.)
One of Exocortex's most popular tools is our Alembic suite of data converters. We hope to support Alembic in and out of Clara.io in the future. That will considerably help interoperability.
Platform lockdown is completely unnecessary and unacceptable; professional customers need to plan for your company going out of business and losing all their data instantly and without warning (not that I'm wishing you ill, but even in the best scenario you are going to remain a small and unproven company for a long time).
We support exporting and importing in most common formats (FBX, Collada, ThreeJS, STL and Obj to start), so lock in shouldn't be too much of a problem.
Exocortex has been around for 7 years and our tools are used quite widely in the visual effects industry (almost every major VFX film uses at least some of our tools), so we are not completely unproven. Our stuff was used on a lot of recent movies including Pacific Rim (which is awesome, go see it!), Star Trek Into Darkness, White House Down, Iron Man 3, The Avengers, Harry Potter 7, Titanic 3D, Jurassic Park 3D, Hansel and Gretel: Witch Hunters, Hunger Games 2 (this fall), Jack and the Giant Killer, Snow White and the Huntsman, to name just some of the bigger names.
If my Internet access works, if your hosting provider doesn't have arbitrary downtime, if your servers aren't overloaded or offline for maintenance, if... Additional risks are part of the cost of any cloud-based service, and for many people the anxiety of losing control is priceless.
Getting this right is a big concern of ours as well. It is possible to get it right though. Cloud services are not for everyone, that is for sure.
here are many 3D modeling tools. Does Clara.io do something better than existing software of comparable cost? In particular, does it do something better than Blender? Why do you think a cloud-based system, with the unavoidable hazards of data loss and data interception, is a good idea? (A web-based client could work, more reliably, with a dedicated server within the customer's network.)
The pricing of Clara.io is a lot more comparable to Blender than it is to comparable commercial products and we hope to keep it that way.
We agree that cloud-based storage isn't safe, but if I have to keep a local copy of my files the ease of use and the cost reduction disappear.Backup and version control are related aspects, and I don't see how you can be competitive with local storage in a VCS repository as the authoritative source (better quality than your own history management, if only because it can include documents, code and anything else along with 3D models) and cloud backups in generic file storage services (unavoidably lower cost than your service).
We offer our clients the ability to license our system and install it in house. We already do these types of deals with a lot of our existing clients with our Alembic tool set, so we are flexible to meet our client needs.
Our history management tracks all changes related to a Clara.io scene. You are free to track things externally as well if you need collateral. We are not aiming to be a replacement for Shotgun if that is what you are thinking of.
One thing that I think you are ignoring and that I have found to be very true is that administration, configuration, deployment and maintenance of internal services are incredibly costly. Also the sticker price for commercial tools is multi-thousands per seat. We are much cheaper in cost and our total cost of ownership, because we are a managed solution, is much lower than do-it-yourself systems.
So in closing, I am not saying that Clara.io is for everyone nor does it replace all tools and all workflows, but I do believe there is space for a solution like Clara.io in the greater ecosystem of game, animation and visual effects tools.