Virtual World Primer for CAD people

By MarkBurhop



Virtual Worlds are a growing segment on the Internet. It has been an area of interest and hobby of mine for few years so it’s fun to watch as it starts to cross over to the mainstream. The basic concepts are not too hard. You have an “Avatar” which represents you, usually some set of assets that your avatar owns, and some type of environment your avatar exists within – the virtual world. It sounds like something more important to gamers and programmers than businesses. It probably was just a couple years ago.

With all the changes and investment going on with virtual world (VW) technology, I thought I’d spend a bit of time talking about how we got where we are and where we are going. Now there are many, many blogs out there on virtual worlds so I thought I’d try to keep this in the context of a CAD users. We do 3D all the time and are perhaps a bit closer to using VW technology than the average person.


 The beginning ideas for Virtual Worlds have been around for some time. The Sensorama machine was created back in 1962. Ivan Sutherland later created what most consider the first head-mounted display system for virtual reality around 1968. If Dr. Sutherland’s name sounds familiar to you, he was the same person that created Sketchpad, the ancestor to modern CAD.

More mainstream use of virtual worlds started showing up in the late 1970’s as computer games and networks started to take hold. Multi User Dungeon (MUD, also called British Legends) came about in 1978 and is considered one of the first virtual worlds. It was text based and used TELNET.

Newer and better applications that use Virtual World concepts continued to grow from here. The ability for avatars to interact, work together on common tasks, share assets and view the environment together can be both useful and entertaining. Still, the technology seemed to be used only in a few small niches. Games are probably one of the big exceptions to this. Most serious investment came from here until just recently.

It is not that there is a shortage of ideas for how to use virtual technologies for things other than games. Ideas are all over in the Sci-Fi world. Just look to movies like TRON created in 1982 or more recently the Matrix. These might be a bit extreme but there are plenty more practical ideas. NASA has made use of some excellent VW simulations. The main problems for those with lesser budgets have been the technology and cost.

Along with pure computing power, a serious graphics processor is needed to render a dynamic virtual world. Here, virtual worlds are benefitting from much of the other work being done for 3D display required for games, movies, science and engineering. It definitely helps to have a high end CAD video card!

Another problem is network bandwidth and latency. For a world to be shared, it must be displayed on each user’s computer. If my avatar stands up or moves a chair, people watching this from their computer should see this in real time (or as close to real-time as possible). That means you need low latency. If you avatar pulls out a model of a rocket engine, that means the geometric description of the rocket must be downloaded to your computer to see it. The more detailed the rocket, the higher bandwidth you need.

Yet another problem is an effective user interface, either hardware or software based, for working in 3D. Looking to Second Life, almost 90% of the people that try it do not return. Part of this is that learning to control your avatar and interact with the 3D environment is hard. Only recently have some of the tools used by CAD developers started to show up in virtual worlds (i.e. 3D mice). Still, there is no common way of working in 3D like there is in 2D with a mouse.

Going back to 2003, this was the point where enough of these technology problems had been addressed to at least make a go at more mainstream virtual worlds. Second Life by Linden Labs got started at this time. It is not the only virtual world out there but is perhaps the most known non-game virtual world being used today. World of War Craft is probably the largest game oriented virtual world. Both of these have several million users.

Today, other virtual worlds and technologies are coming on-line at a very fast pace. Not only does this include proprietary and complete systems like Second Life, it also includes a number of open systems like OpenSim and Croquet, file formats for transferring data between systems (COLLADA), components such as physics engines. Focus on business need is also becoming a priority. For example, some of these virtual world servers can be hosted inside a company’s firewall allowing for Intranet virtual worlds.

Most recently, Google launched Lively, a kind of web based virtual world. While it is perhaps a bit more cartoonish than Second Life, with much less functionality, it is easier to use and likely improve over the coming months and years (it is Google, after all).

What does this mean for the CAD world?

There are several reasons virtual worlds are potentially interesting for engineers, architects, industrial designers, and CAD. Firstly, these worlds are 3D. Your avatar can take out a copy of part or design and lay it on a virtual table. If you design buildings or factories you can create a mock-up and allow other avatars to walk though the design. You can animate the machines. These are things being done today to some limited extent in Second Life.

Secondly, these worlds are naturally collaborative and immersive. Social networking is another hot area in software and internet development and virtual worlds have, to a certain extent, tapped into this. So while social networks of engineers exist in places like Facebook, Yahoo groups or internal newsgroups, virtual worlds provide a way to do this in 3D. You can set up persistent war rooms or product displays and interact with designers and engineers all over the world. Unlike a web presentation or conference call, virtual worlds give a feeling of presence.

All of this is not to say virtual worlds have finally arrived. Graphics cards still need to be faster. Network connections need to be faster and we still need better 3D user interfaces. For businesses, security is still an issue. You certainly don’t want to share your latest design prototype in a virtual world and not control who can see it.

Speaking of sharing your design in a virtual world, this is still a issue that is not getting as much attention as many would like. To avoid problems with network bandwidth, Second Life supports only a limited number of primitives to represent geometry. There are no Booleans and the number of primitives you can practically use in a region is limited. There are a number of people and organizations working on point solutions to this within the limits of existing virtual worlds. Recall that Siemens sponsored some work though the University of Cincinnati for this. If you tour Siemens Innovation connection or some of the other CAD islands, you will see a number of products that have been recreated there. However, we are still a long way from being able to push a button and have the CAD design of your airplane or engine appear in Second Life.

I’m personally looking forward to improvements in VW geometry technology over the coming months and years. They can certainly represent much more complex data than they do today (with little or no increase in network traffic). Such improvements will be a interesting boon to those of us using high-end 3D authoring tools (like us CAD users).

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This article first appeared on the Siemens Digital Industries Software blog at