Youngho Chai

SMI 2012: Short SPACESKETCH: Shape modeling with 3D meshes and control curves in stereoscopic environments

This paper introduces SPACESKETCH, a new kind of sketch-based modeling system that can sketch free-form surface in space. This modeling system combines the advantages of a direct mesh-based sketch in which the user can draw the mesh directly in the space by moving the wand and the control curve sketch to express the detailed shape of the model. The created surface is also divided by using the control curve so that different resolution surfaces can be set for each surface and partially complicated parts can be sketched. While using SPACESKETCH, we introduced the advantages of using a new interface that uses mesh-based sketch and control curve sketch simultaneously to create various models and how to apply multi-resolution. Through this process, we show that mesh-based sketch and control curve sketch simultaneously to complement each other in a multi-resolution real time environment is very useful in concept sketching in a 3D environment using a spatial input device.

Free hand stroke based virtual sketching, deformation and sculpting of NURBS surface

This research is to make a series of NURBS surfaces for the virtual 3D conceptual design and the styling process by applying arbitrary calligraphic strokes. The surface can be modified in real-time free form deformation and sculpting. The suggested algorithm is used to create 3D NURBS surfaces for styling object using free-hand strokes with the posture information of the input wand. The algorithm presented in this paper can help product designers in the conceptual design stage, even if he or she has no idea about the shape of a target product.

Development of an immersive VR display system for 3D digital art

A new 3D digital art and an immersive VR display system are presented. A 3D drawing interface and a real time object modeling, which is using auto 3D strokes, are implemented for 3D digital art. One 3D stroke makes some part of the object in one movement. This 3D modeling method has an advantage in representing complex objects quickly. 2D mouse interface is not appropriate for this kind of 3D stroke modeling task, so 3D virtual environment system with 3D wand interface is realized in this study. And an infrared camera-tracking device is used. Since the user viewpoint and wand are tracked, the user can see different screen display at various points of view and interact with objects directly.

Hybrid interface of a two-dimensional cubic Hermite curve oversketch and a three-dimensional spatial oversketch for the conceptual body design of a car

A spatial modelling system with a new interface which is optimized for automotive design is proposed in the conceptual modelling phase. In the initial sketch stage to set the volume and the ratio of the car, the automotive styling is created using a two-dimensional plane sketch with an accurate input and a designer-friendly interface. The character lines, which have important implications in the design of the car, are drawn with a curve-based oversketch. The shape of the car is modified using area-based modification. A completed two-dimensional model consists of converting the character lines to a three-dimensional car model. In the three-dimensional spatial oversketch stage, the edge and mesh on the surface are deformed by viewing the three-dimensional shape of the vehicle with various views using a spatial input device and stereoscopic display. Edge-based deformation modifies single or multiple edges while maintaining continuity between the surfaces. A sculpting technique is applied to execute special shapes such as the accent lines and the strake lines. A sketch system which can be used by designers to perform three-dimensional spatial modelling is proposed.

Free-Hand stroke based NURBS surface for sketching and deforming 3d contents

This research is to make a series of NURBS surfaces for the virtual 3D conceptual design and the styling process by applying arbitrary free-hand strokes. The surface can be modified in real-time calligraphic stroke based free form deformation. The suggested algorithm is used to create 3D NURBS surfaces for styling object using free-hand strokes with the posture information of the input wand. The algorithm presented in this paper can help product designers in the conceptual engineering stage, even if he or she has no idea about the shape of a target product.

Intuitive Change of 3D Wand Function in Surface Design

According to the target model for a designer to sketch, an effective style or shape of input device can be defined differently. The spatial sketch system that supports various types of wand can help to sketch efficiently. We suggest the idea of changing wand style by altering the posture of a 3D wand. This method allows a designer to work in intuitive ways without being interrupted by complicated menus. We implement the surface drawing and merging technique with the grid based data structure which deals with multiple strokes from various types of wand.

Spatial sketching with the auditory reflection for the plausible virtual conceptual design

Most industrial designers work with a pencil and some plane papers. In spite of the paper-based plane modeling data by these designers, the majority of the industrial modeling data for manufacturing are based on the spatial concept. While converting the designers 2D drawing data to the digital form of 3D industrial modeling, designers intention is often misunderstood or misinterpreted. If the designer can use the spatial modeling tool in their conventional way, it is easy to express their intention and there is no need to transform the 2D drawings to 3D model.