A few weeks ago, I had my first chance to play around with a fully immersive virtual reality (VR) system thanks to the VRLab hosted by AOL. The setup, a room-scale HTC Vive, let me not only look around but even walk around an environment. Having spent years using various CAD systems, primarily SOLIDWORKS, I quickly began asking questions about how I could use the setup not only to explore environments, but also to create. Unfortunately for me, the tools and resources available to create mechanical CAD systems in VR are still lacking.
All of the pieces are in place to have a great VR CAD experience, some of which are reviewed below. Still, there is nothing seamless that exists on the market, and there are a number of hurdles, both technical and practical, to making VR fluid in a MCAD workflow. I have broken those hurdles down into three main areas of exploration: the hardware, the UI and the file management.
Hardware for CAD and VR
The buzzword of VR can mean many things so it is important to understand the practical differences between immersive VR, stereoscopic viewing and augmented reality (AR),as each one has unique hardware constraints.
AR is the use of a camera and display to overlay a model or design onto a real scene. One of the first applications of this was launched way back in 2013 with the introduction of eDrawings AR that used a standard smartphone and mobile viewer. Pretty much anything with a camera and a display can execute AR.
Stereoscopic viewing renders two distinct views from slightly different angles. This is one of the more popular forms of VR thanks to things like Google Cardboard, which splits the display in two halves using software and then uses lenses to magnify and focus the scene. Autodesk announced an A360 Stereo Panorama at its user conference in 2014, while SOLIDWORKS released eDrawings 2017 just recently, which includes an option for Google Cardboard.All of this is a step in the right direction but, in its current iteration, falls short of delivering a fully immersive experience.
Immersive VR takes things to a whole new level but requires a significant investment in hardware such as the Oculus Rift or HTC Vive. The idea behind the headsets (and the rest of the setup) is to trick a user’s brain into thinking they are in a different environment. To do that, additional senses can be included, like movement, using sensors to track your position in a room, and audio, using headphones. Still, the biggest struggle is the display.
In order to trick the brain, a display system must render and deliver visuals at a rate that mimics the human eye. Functionally, this means delivering any video at a rate of 90 frames per second, or risking motion sickness. In addition to that, the physical display must be functional when placed a few inches from your eyes. For the Oculus and HTC Vive, that translates to dual screens, each displaying 1080 x 1200 pixels at 90 Hz.
Those stats are nothing to sneeze at. In order to deliver video of that quality, a hardware system must be designed to maximize graphical output. You may think that a standard CAD workstation has plenty of computing power to do this, but it is not so simple. Most great GPUs such as the NVIDIAGeForce series are dedicated to other uses, including gaming, while the real heavy lifting of a CAD workstation is done by the CPU and requires graphics cards from the NVIDIAQuadro line of cards. NVIDIAdetails the differences in the GPU lines in a 34-page document titled “NVIDIA Quadro vs. GeForce GPUs.” In short, CAD workstations are optimized to be significantly more precise and reliable than consumer-grade graphics.
Hardware challenges are nothing new for CAD though. Consider that before the launch of SOLIDWORKSin the mid-1990s, all CAD systems were custom designed for hardware that ran $20,000 or more. MCAD systems were made for enterprise customers who could justify the investment, and a lot has changed since then. Vice projects that there may be 13 million capable PCs in the market and there are reportedly more than three million installs of SOLIDWORKS around the world.
Still, the CAD industry is constantly on the leading edge of technology and typically pushes the boundaries of computing power. As applications move into the cloud, new struggles will appear in order to improve rendering and simulation techniques. Onshape launched its cloud-based system last year and announced a partnership with Magic Leap, which lists Google as one of its investors. Cool marketing videos aside, it is difficult to imagine an Internet connection capable of processing accelerometer data, passing it to the cloud for tilt/zoom/rotate commands and then returning the simulation seamlessly while still allowing for input controls to model.
All of this is to say that processing the backend computations to create and edit CAD data and then displaying it back to a user in real time requires some serious computing power. Even the display and rendering is difficult, as the quality of CAD files is significantly better than traditional gaming. For the time being,expect that most MCAD-based VR applications will be limited to design reviews while creation and engineering changes may lag a few years.
VR Creation Tools
Hardware limitations aside, there are some very cool VR creation tools already on the market. Two of the bigger ones are TiltBrush and SculptrVR, both of which I was able to try at the AOL VRLab. To put them in some context, these tools are VR equivalents of ZBrush and Minecraft (not mechanical design systems like SOLIDWORKS or Fusion).
TiltBrush has some hints of CAD design. The controllers are fairly free form, and it is certainly more artistic, but the pallet also includes the option for mirroring and straight-line sketching. It stops short of any dimensioning tools, but the latest update allows users to zoom in and out of scenes, greatly enhancing the detail potential.
Creating via traditional MCAD tools and importing are possible, but they are not very straightforward. Even though everything might seem the same, the file types used in parametric modeling software is very different from VR. Just ask anyone who has tried to export a native SOLIDWORKS file to an OBJ format (which is accepted by unit). This means that the worlds and resources exist to create new zombies easily, but things like complex mold bases and sheet metal are lacking.
Currently, it can be tricky getting SOLIDWORKS files directly into VR. The best way I can find right now is to export to an STL file and then use something open source, like MeshLab, to convert to an OBJ file. From there,the files should be able to load in a VR system relatively well. This might be changing, as the most recent release of SOLIDWORKS eDrawings 2017 includes support for OBJ files in the eDrawings tool and even has the aforementioned stereoscopic viewing display.
Nathan Bettie, currently director of Virtualex, a VR studio based in Melbourne, Australia, was one of the early developers to showcase manipulating a CAD file in VR. In an email exchange, he glossed over the import and conversion issues and noted, “The big problem you’ll have is optimization. If you’re bringing in huge or complex models, it's going to create poor performance, which will lead to your users getting sick. There's ways of overcoming this by automating the optimization process, but it's definitely not a perfect system just yet.”
A few companies have emerged to handle this sort of seamless conversion, including InsiteVR. On a technical level, it can handle the part conversion but, according to one of its technical specialists, Sam Arsenault, “The [MCAD] industry is very different, and we are focusing on the needs of large architecture, engineering and landscaping firms.”
I also ran into a few engineers from a leading automotive original equipment manufacturer at the solidThinking CONVERGE conference recently who noted they have a few headsets, Oculus and Vive, setup in their office. It took them a while to get files setup, but ultimately, designing in Alias and exporting to Autodesk's VRED workflow seemed to work. The biggest issue they currently run into is screen resolution, which, again, highlights the hardware constraints.