WsamIs- REALITY? Virtual Reality (VR) is the use of computer models that allow users to interact with an :irtificial envi- ronment. Fifteen years ago this requirtld computing power so massive that only governments and huge corporations could afford it, and even nrlw a com- mercial airline flight simulator might cost several million dollars. However, the performance of’person- al computers has multiplied about 500 times since 1988, and costs keep going down. If automotive technology had progressed that fast, cars today might get 5,000 miles per gallon and cost under $2,000. With this new computing capacity, VR has come to the desktop for an increasing number of applications.

At Pine Technical College, a small public institu- tion in rural Minnesota, the Johnson Center for Virtual Reality has been working since January of 2000 to build effective and affordable VR simula- tions for education and industrial training (see Fig. 1). One of these simulations allows people to learn and practice the art of spray painting without the expense and bother of paint booths, VOC emissions, respirators, or even real paint, This article will dis- cuss the basics of VR, the equipment required, and how these have been adapted to spray painter train- ing that is fast, effective, safe, and affordable.

V&based training uses computer software and hardware to simulate real-life situations for train-’ ing or education, Users can navigate in a believable and responsive three-dimensional computer model and interact with the objects and environment they find there.

Simulation sophistication and complexity covers

features. The Spra immersive range.

t simulation f&Is into

SYSTILM cm There are four major components to th simulation system: haMware, softwar model, and the simulation logic.

Hardware The hardware includes the computer and its side0 capability, a motion tracking system, a hea t- ed or projected display, and a variety of Inca control devices. The computer used for SprayPaint is an off-thc-shelf personal computer wi$&P-G&Iz er faster clock speed, Windows 2000 o system, and high-end video processing cap ost new upper-end machines would qualify. The motion -) t rackirl.2 “‘stem is a little more specialized. A$rans- mitter t’r’~~~tc:s a hemispherical electromagnetic field with a r:~d~ us of about 8 feet. Within that field, small receivers can report back their position and orienta- tion about 40 times per second. One rec&er is used to monitor the position of a spray gun &kup and another can control the virtual ca which the user sees the virtual world.

lik,&&d how they should be ren- g b$&e user. About 50 times a sec-

are takes a “snapshot” of the virtual vers it to the computer’s screen and

The first VR training evaluated d&plays an i steel pan&&‘the rever~$&ninated tieen.

Using a mock spray gun, painters are able to stand in front of the screen and “coat” the panel with imag->; inary paint. Even though the software is still bein@ developed the results are astounding. Anyone can paint, regardless of whether the person is a r, supervisor, engineer, or homeowner. It is fk&~..‘&~h like playing video games, and there is no dirt or mess. No paint is used, no hazardous waste, no YQC emis- sions, and best of all, no spray gun to &ML You can learn to paint dressed as you are-you don’t need to : wear a respirator, gloves, coveralls, or anything else. A,: It’s one very sophisticated computer program; ,‘-

, ,“’

ii”

/

the.&play devices. For comp&&on, movies run at 24 !&#nes per second (fps) an~:&levision at 30 fps. At a 50-fps rate, there is no noticeable,@ between a user’s action and when it shows up display. This is an important part of making the Simulation feel real to the user. The VR Framework talks to the peripheral devices, keeps track of virtual object col- lisions, controls and monitors the various states of the simulation, records user performance, and han- dles start-up and shut-down phases.

Virtual Model The virtual model includes all of the objects in the CNANGING SPIIJXL PANAMETENS simul@&n and is created in 3D modeling software. In The computer operator sets the desired fan width by

t these objects include the vir- entering 4, 6, or 8 in. into the front e ’ ware. The s&ware calculates the fan

the assumption that the orifice of the is 8 in. from the screen. Clearly, it is n the operator to modify these para

The fan pattern is depicted by ator has the ability% change the

iors. After modeling, the whole set of objects is m nor axes to imitate q Q@ical spray pat- imported by the scene-graph processor described te above. Other virtual objects may be created, modified, or destroyed during real-time as the simulation pro- gresses. In Spray%int, for edple, the appe

is actual& a series of entation of the apww of paint + #” /, ,’ the user interface.

y the color of the e paint. Low builds are &own in gray, correct

@%lms are colored red. rigger of’ the spray

a%erns have a

Ratio 6:l

.I I

Ratio Retlo 3:l 1:1

R&o 1:6

V W M8]or wls

e trigger too long, ter of the fan pat-

ack to red, indicat- too&uch paint has applied and a sag

tu red can also

sensitivity may be set so that, the p&&+r has to grossly mess up before the bla&will turn b red. As the painter becomes more adept at eontr&ing the gun the sensitivity can be increased. Like most video games, the level of competency can be increased as the user becomes more proficient.

Before we start to train a painter he/she is given an opportunity to trigger the gun and evaluate the fan size and sensitivity to film thickness. The com- puter operator then clears the screen and the painter can start with a fresh imaginary panel. With&t any prior coaching we allow the painter to

rrect Film Build

this time started

was paintin& we ed that during each stroke 3’& r arm from left to right an&,$:.. :‘~.~~ distance from the s~ree~~~$P’

Since no real paint was being used, the instru&& :F~ could stop her in her tracks so that she CCX$$ see how the gun was being turned outwa&‘)a&she reached the end of d stroke. The corn cleared the screen and Sue was off time did a better job at controlling h

Sam was a veteran paint4 strate his expertise. @E had tern and we watche&+ he of overlapping his s the usual method, repeatedly coveting the same areas already painted. By the time he comple

at; willigg to Yolllnteer since.he didn’t want to be

confide~~that he w ers under reabworld

painters w%‘+earn to paint downward. This is useful when painting the roofmd hood of a car, or painting,, 1 component pa&s place& on a tabletop or pa&t. :;’

The ultimate goal is to produce images that represent real surfac opment work will be required to There will be no limit to the number of available for the painter when this opment has been achieved.

when people play non- ey get hooked and contin-

higher scores. That all the games that

OS. With VR painter

coNcwsIows

that results can be achieved quickly at a relatively low cost. Several painters can be trained hands-on

components are used. With a compute& p&nter can practice painting teehniq without producing hazardous waste,

“Training Electroplaters Since 1947”

he Director of the Johnson

I/ GROUP TRAINING PROGRAMS

ti ON-SITE TRAINING PROGRAMS

ti CUSTOM TRAINING PROGRAMS

College in Pine City, Minnesota. Ron Joseph is a Paints and Coatings consultant in

Saratoga, Calif, and spends much of his time training painters in commercial companies and in the military. Visit his website at www.ronjoseph.com or E-mail