Semi-regular Remeshing Research Articles

From stereoscopic images to semi-regular meshes

The pipeline to get the semi-regular mesh of a specific physical object is long and fastidious: physical acquisition (creating a dense point cloud), cleaning/meshing (creating an irregular triangle mesh), and semi-regular remeshing. Moreover, these three stages are generally independent, and processed successively by different tools. To overcome this issue, we propose in this paper a new framework to design semi-regular meshes directly from stereoscopic images. Our semi-regular reconstruction technique first creates a base mesh by using a feature-preserving sampling on the stereoscopic images. Afterwards, this base mesh is passed to a coarse-to-fine meshing process to get the semi-regular mesh of the original surface. Experimental results prove the reliability and the accuracy of our approach in terms of shape fidelity, compactness, but also runtime, since many steps have been parallelized on the GPU.

Segmentation-based semi-regular remeshing of 3D models using curvature-adapted subdivision surface fitting

This paper proposes a novel method of semi-regular remeshing for triangulated surfaces to achieve superior triangles lead to advanced visualization of 3D model. It is based on mesh segmentation and subdivision surface fitting which uses curvature-adapted polygon patches. Our contribution lies in building a sophisticated system with three stages, i.e., curvature-aware mesh segmentation, submesh surface fitting to generate a high-quality semi-regular mesh and finally, stitching the segments using an efficient algorithm. Our method uses centroidal Voronoi tessellation and Lloyd’s relaxation to generate curvature-adapted site centers. Geodesic distances from site centers are used for labeling segments and indexing corner vertices for each segment boundary. Using information of site centers and corner vertices, feature-adapted polygonal patches are generated for each segment. These patches are then subdivided and optimized using squared distance metric to adjust position of the subdivision sampling with segment details and prevent oversampling. At last, an efficient stitching algorithm is introduced to connect regular submeshes together and build the final semi-regular mesh. We have demonstrated the results of our semi-regular remeshing algorithm on meshes with different topology and complexity and compared them with known methods. Superior triangle quality with higher aspect ratio together with acceptable distortion error is achieved according to the experimental results.

A robust feature-preserving semi-regular remeshing method for triangular meshes

Benefited from the hierarchical representations, 3D models generated by semi-regular remeshing algorithms based on either global parameterization or normal displacement have more advantages for digital geometry processing applications than the ones produced from traditional isotropic remeshing algorithms. Nevertheless, while original models have sharp features or multiple self-intersecting surfaces, it is still a challenge for previous algorithms to produce a semi-regular mesh with sharp features preservation as well as high mesh regularity. Therefore, this study proposes a robust semi-regular remeshing algorithm that uses a two-step surface segmentation scheme to build the high quality base mesh, as well as the regional relationship between the original surface and subdivision domain surface. Using the regional relationship, the proposed algorithm substantially enhances the accuracy and robustness of the backward projection process of subdivision vertices based on normal displacement. Furthermore, the mesh regularity of remeshed models is improved by the quadric mesh relaxation scheme. The experimental results demonstrate the capabilities of the proposed algorithm’s semi-regular remeshing to preserve geometric features and have good triangle aspect ratio.

준균일 메쉬 재구성를 이용한 메쉬 시퀀스 압축 기법

최근 공동 연결 관계와 연속적인 정점 위치들의 움직임으로 이루어진 메쉬들의 모임, 즉 메쉬 시퀀스를 압축하는 연구가 활발하게 이루어지고 있다. 본 논문은 Khodakovsky 등이 제시한 준균일 메쉬 압축방법에 기반한 메쉬 시퀀스의 압축 알고리즘을 제시하고자 한다. 준균일 메쉬 시퀀스로의 메쉬 재구성을 이용한 메쉬 시퀀스 압축 알고리즘은 크게 두 부분으로 이루어진다. 첫 번째 부분은 주어진 비균일 메쉬 시퀀스로부터 준균일 메쉬 시퀀스를 생성하는 것이다. 준균일 메쉬를 생성하기 위해 본 논문에서는 MAPS 알고리즘을 사용하였다. 하지만 단일 메쉬에 대해 적용이 가능한 MAPS 알고리즘을 메쉬 시퀀스에 그대로 적용할 수 없다. 따라서 주어진 애니메이션에서의 정점 움직임을 고려하여 유사한 움직임을 가지는 영역별로 분할하고, 이 분할 정보과 정점의 움직임을 고려할 수 있도록 MAPS 알고리즘을 확장하였다. 두 번째 단계에서는 웨이블릿 변형과 메쉬 분할 정보를 이용해 준균일 메쉬를 압축하였다. 각 분할 영역의 변환 정보를 고려해 분할 영역 내 정점의 위치를 예측하고, 참조 프레임과의 차이값을 압축함으로써 효율적으로 준균일 메쉬 시퀀스를 압축하였다. This paper presents a compression method for animated meshes or mesh sequences which have a shared connectivity and geometry streams. Our approach is based on static semi-regular mesh compression algorithm introduced by Khodakovky et al. Our encoding algorithm consists of two stages. First, the proposed technique creates a semi-regular mesh sequence from an input irregular mesh sequence. For semi-regular remeshing of irregular mesh sequences, this paper adapts the MAPS algorithm. However, MAPS cannot directly be performed to the input irregular mesh sequence. Thus, the proposed remesh algorithm revises the MAPS remesher using the clustering information, which classify coherent parts during the animation. The second stage uses wavelet transformation and clustering information to compress geometries of mesh sequences efficiently. The proposed compression algorithm predicts the vertex trajectories using the clustering information and the cluster transformation during the animation and compress the difference other frames from the reference frame in order to reduce the range of 3D position values.

Manifold-based approach to semi-regular remeshing

This paper describes a method for semi-regular remeshing of arbitrary shapes. The proposed approach is based on building a parameterization map which is smooth with respect to a differential structure built on the base domain. A global parametric energy functional is introduced and optimized in order to establish a globally smooth parameterization. The proposed approach avoids using meta-mesh construction during the parameterization and resampling stages which allows for an easier implementation. A simple extension of the method is proposed to improve the approximation properties of the resulting remesh.

Inter-surface mapping

We consider the problem of creating a map between two arbitrary triangle meshes. Whereas previous approaches compose parametrizations over a simpler intermediate domain, we directly create and optimize a continuous map between the meshes. Map distortion is measured with a new symmetric metric, and is minimized during interleaved coarse-to-fine refinement of both meshes. By explicitly favoring low inter-surface distortion, we obtain maps that naturally align corresponding shape elements. Typically, the user need only specify a handful of feature correspondences for initial registration, and even these constraints can be removed during optimization. Our method robustly satisfies hard constraints if desired. Inter-surface mapping is shown using geometric and attribute morphs. Our general framework can also be applied to parametrize surfaces onto simplicial domains, such as coarse meshes (for semi-regular remeshing), and octahedron and toroidal domains (for geometry image remeshing). In these settings, we obtain better parametrizations than with previous specialized techniques, thanks to our fine-grain optimization.