A simple and general method for computing location codes of same-size neighboring nodes for any direction within quadtrees is developed and then extended for octrees and 4-D hyperoctrees. The effect of our algorithm is to ascend the tree, guided by navigational cues, until the nearest common ancestor of the target node and the computed neighbor node is reached. An advantage of our algorithm is ...

The aim of this paper is to characterize the uniqueness domains in the workspace of parallel manipulators, as well as their image in the joint space. The notion of aspect introduced for serial manipulators in [Borrel 86] is redefined for such parallel manipulators. Then, it is shown that it is possible to link several solutions to the direct kinematic problem without meeting a singularity, thus...

This paper describes an algorithm to extract adaptive and quality quadrilateral/hexahedral meshes directly from volumetric data. First, a bottom-up surface topology preserving octree-based algorithm is applied to select a starting octree level. Then the dual contouring method is used to extract a preliminary uniform quad/hex mesh, which is decomposed into finer quads/hexes adaptively without in...

Splatting is an object-order volume rendering algorithm that produces images of high quality, and several optimization techniques have been proposed. This paper presents new techniques that accelerate splatting algorithms by exploiting both object-space and image-space coherence. In particular, we propose two visibility test methods suitable for octree-based splatting. The rst method, based on ...

In this paper we present an efficient method to compute the signed distance field for a large triangle mesh, which can run interactively with GPU accelerated. Restricted by absence of flexible pointer addressing on GPU, we design a novel multi-layer hash table to organize the voxel/triangle overlap pairs as two-tuples, such strategy provides an efficient way to store and access. Based on the ge...

Volumetric visual hulls have become very popular in many computer vision applications including human body pose estimation and virtualized reality. In these applications, the visual hull is used to approximate the 3D geometry of an object. Existing volumetric visual hull construction techniques, however, produce a 3-color volume data that merely serves as a bounding volume. In other words it la...

We present an adaptive deep representation of volumetric fields 3D shapes and efficient approach to learn this for high-quality shape reconstruction auto-encoding. Our method encodes the field a with feature volume organized by octree applies compact multilayer perceptron network mapping features value at each position. An encoder-decoder is designed based on graph convolutions over dual nodes....