The Application of Virtual Reality in the Industrial Design Process
In the early stages of a design project, many CAD sketch models can be created more quickly than physical models. These CAD sketch models can then be viewed and evaluated using VR very effectively. A one on one critique and discussion between a manager or professor and the designer can happen while viewing the designs in VR and on a screen. This allows for a convergence onto a design direction, which can then be further refined as a physical model. At the end of the design process, VR is also more effective at communicating design form and scale to others, than a rendering or other 2D media. This is due to its simulation of depth perception that is close to human visual cognition of physical space.
VR has great potential as a design tool when it can add certain functions. These functions may be contextual environments, exploding and sectioning CAD models, creating and modifying CAD models, and VR group critiques. Virtual reality is an opportunity for designers to form designs in three dimensions directly from their imagination as a digital sculptor without limitations and present them to others without loss in translation.
Objective
Virtual reality is defined as “a realistic and immersive simulation of a three-dimensional environment, created using interactive software and hardware, and experienced or controlled by movement of the body.” (Dictionary.com)The most effective virtual reality systems have accurate head tracking, stereoscopic optics and high frame rates to convince the brain that the images seen are physically present in the viewer’s real space. The potential for applications in industrial design are significant, especially with the visualization of three dimensional design objects. The thesis of this research is that VR can improve the efficiency of the industrial design process through early visualization and evaluation of design concepts. However, the extent of this improvement of efficiency and effectiveness is unknown.
Methods
Hardware
The virtual reality system used in this experiment is the HTC Vive Steam VR. This system has an advantage of having “room scale” VR where the viewer can move about a defined space and interact with the virtual world by walking, crouching or turning around. At the time of this experiment, it was also the only system with effective and interactive controllers allowing one to move, grab objects, and point with a virtual laser pointer.Software
At this time there is very limited availability of useful applications for industrial design visualization and CAD modeling.Mindesk is in alpha stage of development and it allows for viewing of CAD objects as a Rhinoceros plug-in. However, there was no ability to move within the VR space. The lag was high, frame rates were low, and it didn’t have the ability to apply materials or colors to models.
Prospect is a better developed application of viewing CAD models specifically for architecture. It displays a scale model of the CAD model that sits on a virtual table, which the viewer can then view at full scale and experience an architectural design. Its limitations are that the professional version is cost prohibitive for educational use and its focus on architecture makes it less useful for smaller scale objects.
Sketchfab is a web application which is able to view 3D models in VR space. While the website shows great potential, it needs a special experimental browser, such as the Nightly version of Firefox, to run correctly. Another problem is that the scale of the model is frequently skewed and the frame rates are too low, resulting in lag time based on the complexity of the model. Sketchfab also does not recognize and apply materials from CAD applications, such as Solidworks, so models are displayed as solid white.
Through various disappointing experiences with these immature VR CAD applications the best solution was to create an application for ID using the Unity game engine.
Unity
The Unity game engine is an application for video game development, but has the ability to create VR games for the HTC Vive. Steam VR has a plug-in that provides scripts for headset tracking, controller tracking, teleportation, and inputs. The benefit of using this application was having full control of creating a VR gallery, but the downside was learning a new application and some C# script programming.Since industrial design students and professionals are proficient and trained in existing CAD modeling applications, such as Solidworks or Rhinoceros, it was determined that the best use of VR was to be a viewer of CAD models in virtual space. While industrial designers can view their CAD models on a two dimensional screen, it can be difficult to visualize three dimensional form and scale in this method. It is common for a designer to spend hours working on a design on screen and then, after 3D printing a prototype, be surprised to see it in three dimensions. The reason for this disparity is explained in the section “Theory of Visual Perception” below.
The professor learned to create a "scene" in Unity which formed a virtual gallery in which to view the design models. It required the use of the SteamVR plug-in and several controller scripts that allowed for basic teleportation and a laser pointer for interactions with the professor and student.
Design Process
The design process of this project was with 3rd year industrial design students who have had several projects requiring physical modeling and a few projects that required CAD models. They were trained in Solidworks, Rhinoceros and Keyshot. The subject of the project was Smart Home Artificial Intelligent Systems and the length was 11 weeks. The design phases were as follows:1. Research and problem discovery
2. Conceptualization – writing and sketching
3. Refinement - CAD sketch models and VR design review
4. Convergence - CAD models, physical models and VR design review
5. Revision and refine - CAD modeling with assembly and injection molding considered
6. Presentation - 3D printed models, CAD renderings, animations, presentation
After the conceptualization phase, which was done through sketching and brainstorming on paper, students selected at least five design forms to create quick CAD sketch models for critique and evaluation. These models were modeled to scale, arranged together in Rhinoceros, and included a one foot cube in the model for scale determination. From Rhinoceros they exported the models to an OBJ or FBX file which creates a polygon mesh importable to Unity. These CAD sketch models took the place of physical foam sketch models that would typically be made in this stage of the design process.
The student used the VR headset to view their designs while the professor viewed what they saw on the PC screen. The student used the laser pointer to point out features which were visible also on the PC screen, so a discussion could occur about the design. The headset was then switched to the professor for VR viewing. After critique and review of these CAD models, a single direction was selected and then refined for the next week. This CAD model was revised and refined iteratively and then exported again into the VR gallery. Another design review was done using the method described previously.
In another project with 2nd year ID students, VR was used as a method of exhibition of designs at the end of the project. Students were designing exhibition trade show booths, modeling them in CAD and then exporting these models for viewing in VR.
Theory of Visual Perception
Humans perceive the world in three dimensions through the visual ability of depth perception. The perception of depth comes from visual cues through monocular and binocular sensory information. (Burton HE) The difference of these two types of information demonstrates why VR is more effective than a flat screen for understanding three dimensional objects.
When viewing a CAD model on a 2D screen, one is seeing a monocular interpretation of 3D information. This view is determined by the software which simulates a camera which has variable perspective (lens length) and distance from the object. For a CAD model the monocular cues of depth perception as seen on a flat screen can be perspective, relative size, texture gradient, occultation, lighting, shading, and elevation. A rotating CAD model also exhibits depth cues such as motion parallax and kinetic depth effects. (Wallach) However, all of these cues and properties are independent and do not correspond to the viewers position in space or the properties of a human eye. The brain must try to interpret this 2D dimensional visual information into three dimensional mental images.
Contrast this to viewing a CAD model using binocular virtual reality with accurate head tracking. This system provides binocular visual cues of depth perception that are so close to physical objects in real space that the brain accepts them as such, and there is no need for interpretive cognitive processing. These visual cues from binocular vision match the viewer’s optical properties and physical position in space. Motion parallax happens when the viewer moves around to view the CAD model. The perspective matches the optics of the human eye and the distance to the object. Stereopsis, or binocular parallax, occurs where each eye sees a slightly different image and uses triangulation to interpret depth.
Another important difference for VR is the presence of oculomotor cues for depth perception of accommodation and convergence. Accommodation is the stretching of the ciliary muscles of the eye lens to change focal length. Convergence is when the eyeballs focus on the same object which requires them to stretch the extraocular muscles which provide a kinesthetic sensation to the brain. (Okoshi) These sensations don’t happen in the same way for flat screens because the screen is at a fixed distance from the viewer.
Results
The result of this application was promising and effective, although it has its limitations due to the lack of effective applications. The effectiveness was observed during the VR design reviews and discussed with the students after the project was completed. Following is a synopsis of this discussion and observation.
Reduced labor and time for early 3D design development.
Typically, designers would make sketch models in foam by shaping and carving and sanding in the shop. There is great value in this method; however it is also slow and laborious. The advantage of creating sketch models in CAD was that designers can do quick iterations, modify proportions easily, and there is no sanding or painting. Designers can create large quantities of design variations quickly, and then view them in VR for evaluation. This process allowed for an efficient convergence onto a design solution.Immediate understanding of design form for evaluation
Viewing the design models in VR was effective in understanding its form and scale. This became important in the evaluation of design options and selection of a direction to pursue for the student. When viewed on a two dimensional screen, each design sketch model had merit because two dimensional representations are limited and can hide flaws in form. When viewed in VR it became apparent almost immediately to the student and professor which designs were the wrong scale or disproportioned and which were of good form.Not a Substitute for Physical Models
While VR was effective as a means of selecting design directions at the early stages of a design project, many students found that it was still important to form and shape a physical model. A physical model has tactile and physical properties that cannot be substituted with digital VR models. However, using the tools together saved time and provided more design exploration.Limited interactivity
Since this VR gallery application was developed with limited understanding and experience with Unity of the C# coding language, there was limited interaction that the viewer could have with the CAD model. We were able to pick up the object and hold it, turn it around and view it up close. At the time of writing there is no feature to section the model or dynamically explode it. These are all possible functions within the Unity application but will require more expertise and experience in programming to include this interactivity.
Findings and Conclusions
Virtual reality can be a useful tool in expediting the industrial design process and has the potential to radically improve the work flow for designers. In the early stages of a design project, many CAD sketch models can be created more quickly than physical models. These CAD sketch models can then be viewed, evaluated and critique using VR very effectively. A one on one critique and discussion between a manager or professor and the designer can happen while viewing the designs in VR and on a screen. This allows for a convergence onto a design direction which can then be further refined as a physical model.At the end of the design process, VR is also more effective at communicating a designs form and scale to others than a rendering or other 2D media. This is due to its simulation of depth perception that is close to human visual cognition of physical space.
Future Potential
VR will have even greater potential as a design tool when its functionality increases. The ability to place design objects within its intended context will help with the selection of appropriate designs that fit their environment. The ability to hold, take apart, and section CAD models will be useful in communicating and inspecting designs. The ability to modify or edit a design within VR space will be important for designers to shape and form objects freely. Finally, the ability to share a design with multiple people on a design team simultaneously for group critique and discussion will be a helpful way for design meetings to be effective.
Industrial design is a process of envisioning a future that doesn’t exist. It currently starts as a mental object in the designer’s imagination and is then translated to two dimensions through drawing, which is then translated to 3D through modeling physically or digitally, and then presented in three dimensional form. Virtual reality is an opportunity for designers to form designs in three dimensions directly from their imagination, as a digital sculptor without limitations, and present them to others without loss in translation.
By Prof. Jason A. Morris
Director of Industrial Design
Western Washington University
Bellingham, Washington, USA
Wallach, H.; O'Connell, D.N. (1953). "The kinetic depth effect". Journal of Experimental Psychology. 45 (4): 205–217. doi:10.1037/h0056880. PMID 13052853.
Burton HE (1945). "The optics of Euclid". Journal of the Optical Society of America. 35 (5): 357–372. doi:10.1364/JOSA.35.000357.
Okoshi, Takanori. (2012). Three-dimensional imaging techniques. Elsevier. pp. 387–387. ASIN B01D3RGBGS
Dictionary.com. accessed March 20, 2017. http://www.dictionary.com/browse/virtual--reality
References
Wallach, H.; O'Connell, D.N. (1953). "The kinetic depth effect". Journal of Experimental Psychology. 45 (4): 205–217. doi:10.1037/h0056880. PMID 13052853.
Burton HE (1945). "The optics of Euclid". Journal of the Optical Society of America. 35 (5): 357–372. doi:10.1364/JOSA.35.000357.
Okoshi, Takanori. (2012). Three-dimensional imaging techniques. Elsevier. pp. 387–387. ASIN B01D3RGBGS
Dictionary.com. accessed March 20, 2017. http://www.dictionary.com/browse/virtual--reality
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Unity VR development tools