3D Mesh Objects Research Articles

EASI-Tex: Edge-Aware Mesh Texturing from Single Image

We present a novel approach for single-image mesh texturing , which employs a diffusion model with judicious conditioning to seamlessly transfer an object's texture from a single RGB image to a given 3D mesh object. We do not assume that the two objects belong to the same category, and even if they do, there can be significant discrepancies in their geometry and part proportions. Our method aims to rectify the discrepancies by conditioning a pre-trained Stable Diffusion generator with edges describing the mesh through ControlNet, and features extracted from the input image using IP-Adapter to generate textures that respect the underlying geometry of the mesh and the input texture without any optimization or training. We also introduce Image Inversion , a novel technique to quickly personalize the diffusion model for a single concept using a single image , for cases where the pre-trained IP-Adapter falls short in capturing all the details from the input image faithfully. Experimental results demonstrate the efficiency and effectiveness of our edge-aware single-image mesh texturing approach, coined EASI-Tex, in preserving the details of the input texture on diverse 3D objects, while respecting their geometry. Code : https://github.com/sairajk/easi-tex

A Non-Gradient and Non-Iterative Method for Mapping 3D Mesh Objects Based on a Summation of Dependent Random Values

A Non-Gradient and Non-Iterative Method for Mapping 3D Mesh Objects Based on a Summation of Dependent Random Values

Volume and Surface Area of 3D Mesh Objects : A Matlab GUI

In many applications of science and engineering, the real physical related objects are usually modelled in terms of mesh objects, where, the mesh will be used during computation or simulation. For most cases, a good mesh is required in order to increase the accuracy of the results. As the mesh represents the original object, the mesh should have similar physical properties of the original object such as the surface area or the volume. However, finding the value of these parameters could require extra computational cost and increase overall time taken to solve the problem. Thus, it might be useful if these parameters can be determined separately to ensure good mesh is used before any simulation is performed. In this study, a Matlab GUI is developed to enable user for easily computing the volume and the surface area of three-dimensional mesh objects. In order to use the GUI, user will firstly need to import the Mesh that is generated by the software Netgen Mesh generator. Once any mesh is imported as an input to the GUI, the program will use the concepts in vectors, which includes dot and cross products, to compute both parameters. Apart from presenting briefly the steps in creating the GUI with Matlab, this paper will also provide some examples to demonstrate the use of the GUI.

Biovolume and surface area calculations for microalgae, using realistic 3D models

Morphology and spatial dimensions of microalgal units (cells or colonies) are among the most relevant traits of planktic algae, which have a pronounced impact on their basic functional properties, like access to nutrients or light, the velocity of sinking or tolerance to grazing. Although the shape of algae can be approximated by geometric forms and thus, their volume and surface area can be calculated, this approach cannot be validated and might have uncertainties especially in the case of complicated forms.In this study, we report on a novel approach that uses real-like 3D mesh objects to visualize microalgae and calculates their volume and surface area. Knowing these dimensions and their intraspecific variabilities, we calculated specific shape and surface area constants for more than 300 forms, covering more than two thousand taxa.Using these constants, the accurate volume and surface area can be quickly computed for each taxon and having these values, morphology-related metrics like surface area/volume ratio, the diameter of spherical equivalent can also be given quickly and accurately.Besides their practical importance, the volume and surface area constants can be considered as size-independent morphological traits that are characteristic for the microalgal shapes, and provide new possibilities of data analyses in the field of phytoplankton ecology.

Direct Write of 3D Nanoscale Mesh Objects with Platinum Precursor via Focused Helium Ion Beam Induced Deposition.

The next generation optical, electronic, biological, and sensing devices as well as platforms will inevitably extend their architecture into the 3rd dimension to enhance functionality. In focused ion beam induced deposition (FIBID), a helium gas field ion source can be used with an organometallic precursor gas to fabricate nanoscale structures in 3D with high-precision and smaller critical dimensions than focused electron beam induced deposition (FEBID), traditional liquid metal source FIBID, or other additive manufacturing technology. In this work, we report the effect of beam current, dwell time, and pixel pitch on the resultant segment and angle growth for nanoscale 3D mesh objects. We note subtle beam heating effects, which impact the segment angle and the feature size. Additionally, we investigate the competition of material deposition and sputtering during the 3D FIBID process, with helium ion microscopy experiments and Monte Carlo simulations. Our results show complex 3D mesh structures measuring ~300 nm in the largest dimension, with individual features as small as 16 nm at full width half maximum (FWHM). These assemblies can be completed in minutes, with the underlying fabrication technology compatible with existing lithographic techniques, suggesting a higher-throughput pathway to integrating FIBID with established nanofabrication techniques.

A blind proposed 3D mesh watermarking technique for copyright protection

ABSTRACTWatermarking provides an efficient mechanism for copyright protection of digital media by embedding information in the object to identify the owner. This paper proposed a watermarking technique that can successfully embed a grey-scale image in a 3D mesh object. In our proposed technique, each three vertices of the 3D object can hide one pixel from the secret image. The experimental results showed that the proposed technique has better visual quality on both the watermarked object and the extracted secret image.

Steganalysis of 3D objects using statistics of local feature sets

3D steganalysis aims to identify subtle invisible changes produced in graphical objects through digital watermarking or steganography. Sets of statistical representations of 3D features, extracted from both cover and stego 3D mesh objects, are used as inputs into machine learning classifiers in order to decide whether any information was hidden in the given graphical object. The features proposed in this paper include those representing the local object curvature, vertex normals, the local geometry representation in the spherical coordinate system. The effectiveness of these features is tested in various combinations with other features used for 3D steganalysis. The relevance of each feature for 3D steganalysis is assessed using the Pearson correlation coefficient. Six different 3D watermarking and steganographic methods are used for creating the stego-objects used in the evaluation study.

Voxelizer plug-in for Blender

This document describes a plug-in for Blender (www.blender.org) that allows to rasterize 3D mesh objects into 3D voxel data, i. e. it allows to voxelize Blender meshes. In 2D, this process can be compared to rasterization of vector graphics into pixel graphics. The voxelization is done by VTK (www.vtk.org) functions. A simple GUI allows to choose the type of voxelization and to specify necessary parameters. Depending on the type chosen, only the surface of the mesh objects is voxelized or the enclosed volume, i. e.“filled”. Beside the size of the output, one can specify if the result should be “anti-aliased” or not. This paper is accompanied with the source code, input data, parameters and output data that the authors used for validating the script described in this paper.

Viewpoint Consistency: An Eye Movement Study

Eye movements have been widely studied, using images and videos in laboratories or portable eye trackers in the real world. Although a good understanding of the saccadic system and extensive models of gaze have been developed over the years, only a few studies have focused on the consistency of eye movements across viewpoints. We have developed a new technique to compute and map the depth of collected eye movements on stimuli rendered from 3D mesh objects using a traditional corneal reflection eye tracker (SR Eyelink 1000). Having eye movements mapped into 3D space (and not on an image space) allowed us to compare fixations across viewpoints. Fixation sequences (scanpaths) were also studied across viewpoints using the ScanMatch method (Cristino et al 2010, Behavioural and Research Methods42, 692–700), extended to work with 3D eye movements. In a set of experiments where participants were asked to perform a recognition task on either a set of objects or faces, we recorded their gaze while performing the ta...

Digitized holography: modern holography for 3D imaging of virtual and real objects

Recent developments in computer algorithms, image sensors, and microfabrication technologies make it possible to digitize the whole process of classical holography. This technique, referred to as digitized holography, allows us to create fine spatial three-dimensional (3D) images composed of virtual and real objects. In the technique, the wave field of real objects is captured in a wide area and at very high resolution using the technique of synthetic aperture digital holography. The captured field is incorporated in virtual 3D scenes including two-dimensional digital images and 3D polygon mesh objects. The synthetic field is optically reconstructed using the technique of computer-generated holograms. The reconstructed 3D images present all depth cues like classical holograms but are digitally editable, archivable, and transmittable unlike classical holograms. The synthetic hologram printed by a laser lithography system has a wide viewing zone in full-parallax and give viewers a strong sensation of depth, which has never been achieved by conventional 3D systems. A real hologram as well as the details of the technique is presented to verify the proposed technique.

On the Effectiveness of Various Techniques of Searching in 3D Mesh Objects in Databases

The article compares some algorithm for object comparison, that can be used for searching 3D objects in database. There are tested: basic D2, TH, and EGI algorithms. The algorithms use histograms as descriptors of 3D shape. The techniques were tested using cultural heritage objects and objects from Shape Princeton Benchmark. Additional test use the same object represented with different accuracy. The tests give us conclusions about the restricted usefulness of the algorithms and suggest the important parameters for searching in database.

Computer generated holograms from three dimensional meshes using an analytic light transport model

We present a method to analytically compute the light distribution of triangles directly in frequency space. This allows for fast evaluation, shading, and propagation of light from 3D mesh objects using angular spectrum methods. The algorithm complexity is only dependent on the hologram resolution and the polygon count of the 3D model. In contrast to other polygon based computer generated holography methods we do not need to perform a Fourier transform per surface. The theory behind the approach is derived, and a suitable algorithm to compute a digital hologram from a general triangle mesh is presented. We review some first results rendered on a spatial-light-modulator-based display by our proof-of-concept software.

Conformal spherical representation of 3D genus-zero meshes

This paper describes an approach of representing 3D shape by using a set of invariant spherical harmonic (SH) coefficients after conformal mapping. Specifically, a genus-zero 3D mesh object is first conformally mapped onto the unit sphere by using a modified discrete conformal mapping, where the modification is based on Möbius factorization and aims at obtaining a canonical conformal mapping. Then a SH analysis is applied to the resulting conformal spherical mesh. The obtained SH coefficients are further made invariant to translation and rotation, while at the same time retain the completeness, thanks to which the original shape information has been faithfully preserved.

Blind Robust Watermarking Schemes for Copyright Protection of 3D Mesh Objects

In this paper, two novel methods suitable for blind 3D mesh object watermarking applications are proposed. The first method is robust against 3D rotation, translation, and uniform scaling. The second one is robust against both geometric and mesh simplification attacks. A pseudorandom watermarking signal is cast in the 3D mesh object by deforming its vertices geometrically, without altering the vertex topology. Prior to watermark embedding and detection, the object is rotated and translated so that its center of mass and its principal component coincide with the origin and the z-axis of the Cartesian coordinate system. This geometrical transformation ensures watermark robustness to translation and rotation. Robustness to uniform scaling is achieved by restricting the vertex deformations to occur only along the r coordinate of the corresponding (r, theta, phi) spherical coordinate system. In the first method, a set of vertices that correspond to specific angles theta is used for watermark embedding. In the second method, the samples of the watermark sequence are embedded in a set of vertices that correspond to a range of angles in the theta domain in order to achieve robustness against mesh simplifications. Experimental results indicate the ability of the proposed method to deal with the aforementioned attacks.