Accurate and Efficient CPU/GPU-Based 3-DOF Haptic Rendering of Complex Static Virtual Environments

Abstract

This paper proposes a novel, accurate, and efficient hybrid CPU/GPU-based 3-DOF haptic rendering algorithm for highly complex and large-scale virtual environments (VEs) that may simultaneously contain different types of object data representations. In a slower rendering process on the GPU, local geometry near the haptic interaction point (HIP) is obtained in the form of six directional depth maps from virtual cameras adaptively located around the object to be touched. In a faster rendering process on the CPU, collision detection and response computations are performed using the directional depth maps without the need for any complex data hierarchy of virtual objects, or data conversion of multiple data formats. To efficiently find an ideal HIP (IHIP), the proposed algorithm uses a new “abstract” local occupancy map instance (LOMI) and the nearest neighbor search algorithm, which does not require physical memory for storing voxel types during online voxelization and reduces the search time by a factor of about 10. Finally, in order to achieve accurate haptic interaction, sub-voxelization of a voxel in LOMI is proposed. The effectiveness of the proposed algorithm is subsequently demonstrated with several benchmark examples.

Depth Cube-Based Six Degree-of-Freedom Haptic Rendering for Rigid Bodies

“…However, it could not provide the full geometry for the hidden side of depth videos since only one side of the virtual scene was captured. Concurrently, Kim and Ryu [25] and Kim et al [26] proposed a 3-DOF haptic rendering algorithm for static virtual objects, in which a precise collision can be detected by a local volumetric geometry, referred to as a local occupancy map instance (lomi). Since the proposed method builds on and improves the lomi, we will briefly review the lomi in the following section, to assist in readers' understanding.…”

“…Since the proposed method builds on and improves the lomi, we will briefly review the lomi in the following section, to assist in readers' understanding. Note that in the rest of the paper, we let the italicized 'lomi' refer to the previous algorithm [26] and the capitalized 'LOMI' refer to the improved one in this paper.…”

“…1g) in order to more accurately search for the ideal location of the SCP. After the true (ideal) SCP is found, the collision response force is computed using Hooke's Law based on the directional vector from the HIP to the SCP; for further details of this algorithm, please see [26].…”

AnyHaptics

“…[Rasool and Sourin 2011] proposed a more direct way to achieve haptic rendering from penetration depth and surface normal direction calculated from the depth image, which is obtained by the depth camera such as Microsoft Kinect T M . One of the haptic rendering scheme utilizing graphically generated depth map data was proposed by [Kim et al 2009]. While the purpose of their work is on achieving an accurate and efficient haptic rendering, it is not directly applicable to our system, though some of their systematic approach inspired our work.…”

Research Status of Haptics in Korea

“…Their research spectrum is very broad, from mechanical haptic interface design to haptic rendering software. Notable recent results include: 1) energy-bounding algorithm for passive and stable haptic interaction [6]; 2) accurate and efficient hybrid CPU/GPU-based haptic rendering algorithm [5]; and 3) tactile movie watching system with a dedicated authoring tool [9] (Fig. 4).…”