Implicit-based Haptic Rendering Technique
Laehyun Kim, Gaurav S. Sukhatme and Mathieu Desbrun. 

Abstract
we present a novel haptic rendering technique based on a hybrid surface representation mixing geometric model and implicit surface representation. Using the hybrid surface representation, we address conventional limitations in the haptic display based on the geometric model,such as fast force update at 1 kHz, correct and stable simulation of surface properties like friction, stiffness, and haptic texture, and avoiding force discontinuity without a feeling of rounded surface. We also present a haptic decoration and material editing technique. Haptic decoration allows the user to paint directly on the 3d model (haptic painting) and then sense the paint thickness spread on the surface (image-based Haptic texturing). Using a material editing technique, the user can edit local surface properties like friction and stiffness and then simulate the assigned material properties on the surface. Finally, we introduce a haptic sculpting system where the user intuitively adds and carves material to a volumetric model using various sculpting tools. The volumetric model being sculpted is visualized as a geometric model which is adaptively polygonized according to the surface complexity.

Papers

	An Implicit-based Haptic Rendering Technique Laehyun Kim, Anna Kyrikou, Gaurav S. Sukhatme and Mathieu Desbrun In IEEE/RSJ IROS 2002 Proceedings.
	Haptic Editing for Decoration and Material Properties Laehyun Kim, Gaurav S. Sukhatme and Mathieu Desbrun In 11th Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems, IEEE Computer Society, 2003.

Downloads
Libraries, data files and an executable (950 KB, Windows 9x/NT/2000 application, requires a 3DOF Phantom device and OpenGL)

Image & video (click on images to get larger ones)

We use a discrete distance field to implicitly encode the geometry. Each node of a grid is assigned a potential value which is proportional to the distance to the surface. The surface is then the isovalue 0 of this field.

Implicit-based haptic texuring: texture values are added directly to the potential values. As a result, the geometry of the implicit surface is changed, and the texture is simulated at no extra cost.

Haptic editing technique for decoration and material properties to allow the user paint and edit material properties and then feel the surface variation due to the painted images and the assigned material properties

The haptic sculpting is to haptically render a volumetric implicit surface and to intuitively deform / manipulate / carve / sculpt the shape (to be published soon).