This paper presents a drawing system to draw shapes in 3D. It consiste of a Tablet PC mounted on the top of a mechanical structure that can move up or down using the dead counter weight and push of the user. Authors believe that by providing the mechanical 3D motion in the Z direction, it will be more intuitive for users to sketch in 3D. The mechanical device is constructed to minimize human effort in pushing/ pulling.
In order to capture the 3D data, they have used a simple potentiometer whose resistance varies with the movement (up and down of the mechanical structure), this information is calibrated to obtain Z value using a Analog to digital converter and provided to the PC via a USB connection.
The user interface of the system consists of a 2D drawing pad and a window which displays the view of the object being drawn by the user. In order to provide the depth cue in 2D, authors tried to use different color cues but found it to be confusing. They also tried using the varying thickness cues but found it also to be non intuitive. Finally they decided to present users with just the information that all thin strokes shown are actually below and users are drawing the top strokes. Similarly authors found out that projective views were more intutive and helpful than the orthographic projections and as such the window which displays the object being drawn shows projective view.Their system also provides provision for deletion so that users can edit their sketches.
They conducted a user study where they asked arts students to get familiar with their system and use it to draw certain sketches. Authors observed that the users liked their system though each user agreed that it was easier to push the table down than to pull it up.Also users reported that it would have been better if they could tilt the surface in the direction they were sketching the object. Also, they complained about alignment issues as they found it difficult to match the 3D symmetry of object being drawn (like top and bottom of Box)
Discussion:
I think it was a cool idea but very uncomfortable as user has to push and pull the table which seems much unintuitive to me. Also I would not be surprised if the user unintentionally pushed the table while sketching as some people tend to sketch with hard hand.
In order to capture the 3D data, they have used a simple potentiometer whose resistance varies with the movement (up and down of the mechanical structure), this information is calibrated to obtain Z value using a Analog to digital converter and provided to the PC via a USB connection.
The user interface of the system consists of a 2D drawing pad and a window which displays the view of the object being drawn by the user. In order to provide the depth cue in 2D, authors tried to use different color cues but found it to be confusing. They also tried using the varying thickness cues but found it also to be non intuitive. Finally they decided to present users with just the information that all thin strokes shown are actually below and users are drawing the top strokes. Similarly authors found out that projective views were more intutive and helpful than the orthographic projections and as such the window which displays the object being drawn shows projective view.Their system also provides provision for deletion so that users can edit their sketches.
They conducted a user study where they asked arts students to get familiar with their system and use it to draw certain sketches. Authors observed that the users liked their system though each user agreed that it was easier to push the table down than to pull it up.Also users reported that it would have been better if they could tilt the surface in the direction they were sketching the object. Also, they complained about alignment issues as they found it difficult to match the 3D symmetry of object being drawn (like top and bottom of Box)
Discussion:
I think it was a cool idea but very uncomfortable as user has to push and pull the table which seems much unintuitive to me. Also I would not be surprised if the user unintentionally pushed the table while sketching as some people tend to sketch with hard hand.
1 comment:
I understand the authors' intent in trying to create a device to emulate the functionality of 3D sketching, but I completely agree with you about not liking the user having to make the effort to displace the drawing surface. It seems quite distracting to do so. Dr. Hammond's idea of having a button to automate that would be a step in the right direction. It still would feel like a hack for something that can't completely solve the 3D sketching problem. A nice concept though.
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