Artists 'draw on air' to create 3D illustrations
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Date posted: 23/09/2007
Posted by: Site Administration
This story is from the category
 Graphics

Slipping an slim line, lightweight stereoscopic HMD over your eyes; each of the two screens sending data to a different eye, giving the same angles in the virtual world as light takes to each eye in the physical. Holding a stylus in one hand, and a 3D pointer in the other. This is the set up for art work, heavy engineering design or model making with ?Drawing on Air?.

The idea is, to draw 3D shapes and structures, it is easiest to draw them actually in the air in front of you; taking shape in all three dimensions. No visible computer system before you; total immersion within the designer.
"If we can boost the precision with which scientists can interact with their 3D data using a computer, then many more scientific uses for virtual reality technology may become possible,"
- Daniel Keefe


The stylus fits in your dominant hand, to trace the lines, curves, or infills. The 3d pointer sits in your other hand, and accesses menus, changing tools and styles, accessing the menu system to export, import, and save.

In addition, both hands may be used together in two-handed mode for drawing. This is based on the ?tape drawing? technique, which is a highly controlled, two-handed method for drawing in 2D. Artists hold a stylus in one hand for drawing and a tracker in the other hand for defining the direction of the line. The artist co-ordinates the movement of both hands to examine the work from different angles and draw accordingly.



Daniel Keefe, one of the creators of this new system, explained the major difficulties such a system entails.

"First, think about a curve found in some interesting 3D shape-the handlebar of a road bike is a good example because it follows a smooth 3D curve. Ok, now take your index finger and try to trace that curve out in the air in front of you. If you were able to leave a trail of paint behind your finger as it moves through the air, what you would notice from this exercise is that drawing a nice shape is really hard to do. First, you would probably notice that your drawing is quite wobbly. Second, you would probably find that the 3D proportion of the form is off."


Drawing on Air uses drawing guidelines, force feedback, and two-handed interaction to help artists draw this type of curve more precisely. The system then transfers the 3D drawing into the computer for use in 3D modelling, design, and illustration programs. In short,

In a trial with 12 trained artists, results showed that Drawing on Air was easy to learn and provided sufficient control to illustrate complex 3D subjects with variety. For example, biologists studying bat flight find accurate 3D illustrations very valuable, since bats have a flexible wing membrane and curved bones that actually bend during flight. Artists in the trial successfully drew bats based on data from a bat flying in a wind tunnel, revealing the details of the animal?s anatomy in motion, and simplifying the uninteresting parts of the body.

?If we can boost the precision with which scientists can interact with their 3D data using a computer, then many more scientific uses for virtual reality technology may become possible,? Keefe said.

?Drawing on Air: Input Techniques for Controlled 3D Line Illustration.? By Daniel F Keefe, Robert Zeleznik, and David Laidlaw will be published in .? IEEE Transactions on Visualization and Computer Graphics, vol. 13, no. 5, September/October 2007.

See the full Story via external site: www.physorg.com