Orientation Mapping Research Articles

A study on the microstructure and mechanical behavior of CoCrFeNi high entropy alloy fabricated via laser powder bed fusion: Experiment and crystal plasticity finite element modelling

Additive manufacturing facilitates the design of high entropy alloys (HEAs) with well-performing properties compared to conventional manufacturing methods. However, a significant obstacle to the industrial application of the equimolar CoCrFeNi HEA fabricated through additive manufacturing is the detrimental impact of thermal cracks on its performance. Here, thermal crack-free CoCrFeNi HEAs with enhanced mechanical properties were obtained by optimizing the energy input in laser powder bed fusion (LPBF). The lower energy input resulted in finer grains, leading to simultaneously improved strength and ductility compared to the one fabricated via higher energy input. To understand the relationship between the microstructure and mechanical properties, crystal plasticity element modelling (CPFEM) was employed to accurately model the experimental results. Using the collected constitutive parameters for CoCrFeNi HEA after CPFEM, in-situ tensile modelling was implemented on a converted orientation map of an as-LPBF CoCrFeNi sample. The CPFEM results reveal that the appearance of deformed twins during the initial plastic deformation stage is attributed to a complex distribution of shear strain on the grain boundaries. The interaction between the deformed twins and dislocation motion emerged as the primary deformation mechanisms in the as-LPBF CoCrFeNi HEA, resulting in complex stress and strain distributions. By combining experimental data with modelling techniques, a viable approach to comprehending the detailed deformation mechanism of deformed twins was established.

A Visual Cortex-Attentive Deep Convolutional Neural Network for Digital Image Design

With the proliferation of advanced visualization techniques in visual communication, enhancing digital image quality remains a persistent challenge. This study presents a sophisticated Convolutional Neural Network (CNN) model to optimize image processing. The model incorporates a multi-stage architecture attentive to biological visual pathways. Inter-subnetwork connections enable integrated feature learning, guided by adaptive weighting of luminance, color, orientation, and edge maps. Spatial and channel attention modules further enrich feature interplay. When evaluated on the LIVE 3D Phase dataset, the approach demonstrates marked improvements, with saliency maps closely mirroring human visual perception. Pearson Correlation Coefficient and Histogram Intersection metrics exceed conventional models, at 0.6486 and 0.7074 respectively. Testing across distortion types reveals strong agreement with subjective rankings, confirming the model's effectiveness. By combining automated feature extraction with insights from visual cortex mechanisms, this bio-inspired CNN framework significantly enhances image optimization and quality. The scalable approach provides a foundation for next-generation computer vision and machine learning applications.

Evaluating Planar Cell Polarity in the Developing Mouse Epidermis.

Epidermal tissues are among the most striking examples of planar polarity. Insect bristles, fish scales, and mammalian fur are all uniformly oriented along an animal's body axis. The collective alignment of epidermal structures provides a valuable system to interrogate the signaling mechanisms that coordinate cellular behaviors at both local and tissue-levels. Here, we provide methods to analyze the planar organization of hair follicles within the mouse epidermis. Hair follicles are specified and bud into the underlying dermis during embryonic development. Shortly after, follicle cells dynamically rearrange to orient each follicle toward the anterior of the animal. When directional signaling is disrupted, hair follicles become misoriented. In this chapter, we describe how to create a spatial map of hair follicle orientations to reveal tissue-scale patterns in both embryonic and postnatal skin. Additionally, we provide a live imaging protocol that can be used to monitor cell movements in embryonic skin explants to reveal the cellular behaviors that polarize the hair follicle itself.

Orientable vertex imprimitive complete maps

<abstract><p>In the work by Li (<italic>J. Combin. Theory Ser. B</italic>, <bold>99</bold> (2009), 447–454.), the author characterized the classification of vertex transitive embeddings of complete graphs, and proposed how to enumerate such maps. In this paper, we study the counting problem of orientable vertex imprimitive complete maps, which is the automorphism group of this map acts imprimitively on its vertex set. Moreover, we obtain the number of non-isomorphic embeddings when the vertex-stabilizer subgroups of the automorphism groups of maps are isomorphic to $ \text{Z}_{p-1} $ with odd prime $ p $.</p></abstract>

Parent Grain Reconstruction in an Additive Manufactured Titanium Alloy

Electron backscatter diffraction (EBSD) is an excellent tool for characterizing the crystallographic orientation aspects of the microstructure of polycrystalline material. In some additively manufactured materials, the material may undergo a phase transformation during the forming process. Although EBSD can only characterize the final microstructure, neighbor information from orientation mapping allows the microstructure before the phase transformation to be reconstructed, provided that the parent–child orientation relationship is known. An investigation of the effectiveness of the reconstruction algorithms for capturing the grain size as well as orientation gradients is undertaken with a focus on additively manufactured Ti-alloy. The EBSD results, coupled with reconstruction algorithms, reveal information on the prior grain size as well as the plastic flow of the material.

High strength and ductility in a new Mg–Zn–Ga biocompatible alloy by drawing and rotary forging

A comparative study of the effect of drawing and rotary forging on the structure, mechanical and corrosion properties of a new biodegradable magnesium alloy Mg–2Zn–2Ga was carried out. The original 6 mm diameter bars obtained by hot extrusion were reduced to the diameters in the range 5.5–3.3 mm by drawing or rotary forging. Optical microscopy, scanning electron microscopy and EBSD grain orientation mapping were used to characterize the material microstructure. Tensile testing was performed to determine the mechanical properties. The optimum temperature for rotary forging and annealing after each drawing pass for defect-free bar production was found to be 300 °C. The combination of the highest strength and ductility was achieved in the 4.2 mm diameter drawn bar and is explained by the formation of numerous twin boundaries in the alloy structure. The 3.3 mm diameter bar obtained by drawing as well as the 5.5 mm diameter bar obtained by rotary forging showed a balance between high strength (260–310 MPa) and large elongation (9–12 %). The analysis of the stress-strain curves using Hollomon's equation was conducted. The hydrogen evolution test in Hanks' solution revealed that the drawn bars of diameters 4.2 and 5.2 mm, as well as the rotary forged bar of 5.5 mm possessed 3 times lower corrosion resistance reduced in comparison with the original 6 mm extruded bar. The 3.3 mm diameter drawn bar exhibited the lowest nominal corrosion rate of 0.11 mm/year that offers excellent opportunities for use in medical implants.

In Situ Uniaxial Compression of Textured Magnesium AZ31B

Strain-controlled uniaxial compression tests on textured magnesium AZ31B sheet samples were carried out using a 5 kN Kammrath & Weiss tension–compression in situ stage using a scanning electron microscope in combination with real-time electron backscatter diffraction lattice orientation mapping. The distribution of deformation twins in the samples was studied and correlated with the results of finite element simulation of the elastic strain to show that bands of twinned grains formed in areas where the principal compressive stress (σ3) was a maximum, and they formed normal to the trajectory of the principal direction of σ3. This was correlated with maps of lattice disorientation within the grains, which showed the inclination for twins to grow in alignment with local and larger-scale distributions of elastic strain. Mappings of the same area at different values of strain were made to examine the formation and growth of individual twins within the macroscopic bands of twinned grains. All the twins observed were consistent with the extension-type twin, with 86.3° disorientation with respect to the parent grain. Mappings of the grain internal disorientation were related to the elastic strain, and it was found that twin formation and growth followed the contours of the highest elastic strain within and across grains. The maximum angular disorientation found within the grains was approximately 10°, suggesting that this might correspond to a threshold of elastic strain required to initiate twinning.

SAB-Enabled Room Temperature Hybrid Bonding

3D integration is gaining more and more interest for a large panel of applications including CMOS Image Sensor, High Performance Computing, DRAM including HBM stacks and display. Image sensors based on hybrid bonding 3D stacking are the state-of-the-art in imaging applications[1]. Highest integration densities with micron-size pixels are achieved using copper-oxide hybrid bonding in advanced CMOS Image Sensor (CIS) processes. Recently, functional imagers with sub 1 µm pitch of hybrid bonding interconnection have shown great performances in term of reliability [2]. Hybrid bonding low temperature (< 300°C) is increasingly requested by the industry to reduce thermal budget of sensible chips integration such as Image sensors, displays, or memory. Surface Activated Bonding (SAB) is one of the most promising method to enable very low temperature hybrid bonding as very early proposed by Suga et al [3]. Up to know, they have been mainly performed using modified SAB technology [4] or with Oxide recess [5].In this study, 200 mm wafers with 2.5 µm copper pads spaced 2.5 µm apart (5 µm pitch) in a silicon oxide matrix are used. SAB uses argon atom bombardment as surface activation. This bombardment is performed in UHV (ultra- high vacuum) at room temperature during several tens of seconds. Surface copper oxide is removed during the activation, leaving dangling metallic bonds on copper pads surface. Under UHV, two identical wafers are then immediately bonded at RT under a low pressure of 0.3 MPa. Noteworthy, no precise alignment is performed for this hybrid bonding. In order to better understand bonding behavior, a first part of the study focuses on the etching effect due to argon bombardment. AFM (Atomic force microscope) inspections are performed on such activated hybrid surfaces. Then the SAB bondings are characterized by SAM (Scanning Acoustic Microscopy) with or without annealing at 150°C and 200°C during 2 hours. Once the top silicon is removed by grinding, further characterizations such as TEM (Transmission Electron Microscopy) and ACOM (Automated Crystal Orientation Mapping) are carried out. For comparison purposes, standard atmospheric hybrid bonding samples are also fabricated at an annealing temperature between 200°C and 300°C. They are characterized in the same way.SAB for hybrid bonding proves its relevance in this study. Indeed, all bonded samples are successfully grinded and thinned out leaving only the damascene structure (which thickness is around 1 µm) above the bonding interface. Despite oxide/oxide and copper/oxide weak SAB interface, the thinning success for the non-annealed sample demonstrates that enough copper/copper interfaces are successfully obtained. As first suggested by AFM scans after surface activation (Figure 1) and subsequently confirmed by SAM, optimized CMP dishing and etching generated during the SAB activation step allow contacting the copper pads at room temperature. However, improved bonding closure is shown by SAM on the annealed samples. Besides, TEM sections show an excellent copper bonding interface on every SAB samples, even those without annealing. These characterizations have been performed on both SAB hybrid bonding samples and atmospheric ones, allowing comparing both processes and a better understanding of hybrid SAB ones. As could be seen on figure 2, the great copper bonding quality could be summarized by a rebuilt of the copper grains (triple grain boundaries at the interface) and the presence of few defects in the bonding pads. In addition, ACOM provides information about the crystallography of the copper pads all over a section in the bonding. SAB seems to have an effect on the pad crystallography. This will be discuss regarding the process differences.To sum up, bonding of hybrid surfaces at room temperature is successfully realized thanks to SAB. SAM characterizations after bonding, mechanical strength in grinding and TEM images confirm that this process is more than promising in the field of low temperature hybrid bonding. In the wake of these encouraging results, new vehicles including electric test structures are to be bonded with alignment in a SAB system. This new study will allow not only to validate the process on aligned bonded structures but also to qualify the electrical performances of hybrid SAB. Figure 1

A novel image processing procedure for the quantitative evaluation of dental enamel prism arrangement.

Enamel prism is the main microstructural unit of mammalian enamel which composed of hundreds of bioapatite nanocrystals. Prism structure plays a key role in the excellent mechanical performance of dental enamel during millions of chewing cycles without significant remodeling. Thus, quantitative understanding of prism architecture is of utmost importance for biomechanical materials design. To characterize enamel prism orientation quantitatively, a novel image processing method has been developed. Our method is based on scanning electron microscopy images of etched enamel surface and consists of an ellipse fitting procedure, which provides a numerical approximation of prism shape and orientation in the studied cross section. The obtained analytical data allow to construct color coded orientation maps, which provide quick and useful insight into the microstructure of enamel. Besides striking visualization, orientation maps allow to extract and plot the rich information on the azimuthal and inclination angles of the prisms as function of location. Numerical data on prism arrangement can be analyzed using statistical tools over large areas, which paves the way towards quantifying comparative investigation of prism arrangement either in dentistry research or evolution biology. The application of the method is demonstrated for a distal-mesial cross-section of sound human tooth enamel. HIGHLIGHTS: Scanning electron microscopy images of etched enamel surface are analyzed using ellipse fitting. Geometrical parameters of the fitted ellipses provide numerical data of thousands of prisms. Prism arrangement is visualized on color coded orientation maps and analyzed using statistical tools.

Ambient grain orientation imaging on complex surfaces

Crystal orientation imaging is generally confined to the laboratory, typically following destructive sectioning, with most current techniques reliant on electron-material interactions that require a vacuum. This information is gathered in a manner that requires careful planning, however a more desirable approach would allow the manufacturer to acquire this data non-destructively at the point of manufacture, with little or no time penalty. We show that coupling a numerically controlled etching method to topographical data processing can be used to spatially map grain orientations over planar and non-planar surfaces. Our method allows the construction of large area orientation maps (≈400 mm2) in agreement with electron backscatter diffraction datasets. We have characterized spatial and angular resolution limits for the technique, which are correlated to length scales of microscale etch surfaces and our ability to measure their geometries. This approach has the potential to augment materials processing technologies, where resultant microstructures require strict control in order to guarantee through-life integrity.

Comparison of Laboratory Diffraction Contrast Tomography and Electron Backscatter Diffraction Results: Application to Naturally Occurring Chromites.

Understanding how minerals are spatially distributed within natural materials and their textures is indispensable to understanding the fundamental processes of how these materials form and how they will behave from a mining engineering perspective. In the past few years, laboratory diffraction contrast tomography (LabDCT) has emerged as a nondestructive technique for 3D mapping of crystallographic orientations in polycrystalline samples. In this study, we demonstrate the application of LabDCT on both chromite sand and a complex chromitite sample from the Merensky Reef (Bushveld Complex, South Africa). Both samples were scanned using LabDCT and Electron Backscatter Diffraction (EBSD), and the obtained results were rigorously evaluated using a comprehensive set of qualitative and quantitative characterization techniques. The quality of LabDCT results was accessed by using the "completeness" value, while the inaccuracies were thoroughly discussed, along with proposed potential solutions. The results indicate that the grain orientations obtained from LabDCT are comparable to that of 2D EBSD but have the advantage of collecting true 3D size, shape, and textural information. This study highlights the significant contribution of LabDCT in the understanding of complex rock materials from an earth science perspective, particularly in characterizing mineral texture and crystallography in 3D.

Laser powder bed fusion spatters of Zr-Cu-Al-Nb metallic glass

Understanding the morphology, composition and structural changes experienced by metallic glass powder particles upon laser powder bed fusion (LPBF) is the first step towards evaluating the impact of spatter generation on part quality and on feedstock degradation. This study presents the characterization of Zr-Cu-Al-Nb spatter particles by means of scanning and transmission electron microscopy with automated crystallographic orientation mapping and energy dispersive spectroscopy, and X-ray photoelectron spectroscopy. The powder exposed to the LPBF environment exhibits an average surface composition similar to the original feedstock, but with a rougher morphology. The typical spatter encountered in the remaining lack-of-fusion is a vapour-entrained particle, which probably underwent partial melting leading to the formation of α-Zr(O) dendrites, and “big-cube” Cu2Zr4O nanocrystals in its heat affected zone. In the present work, spatter characteristics are discussed considering glass properties and their connection to lack-of-fusion defects is addressed.

Wafer-Scale Fabrication of 2D Nanostructures via Thermomechanical Nanomolding.

With shrinking dimensions in integrated circuits, sensors, and functional devices, there is a pressing need to develop nanofabrication techniques with simultaneous control of morphology, microstructure, and material composition over wafer length scales. Current techniques are largely unable to meet all these conditions, suffering from poor control of morphology and defect structure or requiring extensive optimization or post-processing to achieve desired nanostructures. Recently, thermomechanical nanomolding (TMNM) has been shown to yield single-crystalline, high aspect ratio nanowires of metals, alloys, and intermetallics over wafer-scale distances. Here, TMNM is extended for wafer-scale fabrication of 2D nanostructures. Using In, Al, and Cu, nanomold nanoribbons with widths < 50nm, depths ≈0.5-1µm and lengths ≈7mm into Si trenches at conditions compatible is successfully with back end of line processing . Through SEM cross-section imaging and 4D-STEM grain orientation maps, it is shown that the grain size of the bulk feedstock is transferred to the nanomolded structures up to and including single crystal Cu. Based on the retained microstructures of molded 2D Cu, the deformation mechanism during molding for 2D TMNM is discussed.

3D characterization of abnormal grain growth in nanocrystalline nickel

AbstractAbnormal grain growth, a pervasive phenomenon witnessed during the annealing of nanocrystalline metals, precipitates a swift diminution of the distinctive properties inherent to such materials. Historically, conventional transmission electron microscopy has struggled to efficiently procure comprehensive five‐parameter crystallographic information from a substantial number of grain boundaries in nanocrystalline metals, thus inhibiting a deeper understanding of abnormal grain growth behavior within nanocrystalline materials. In this study, we utilize a high‐throughput characterization method—three‐dimensional orientation mapping in the TEM (3D‐OMiTEM) to characterize the crystallographic five‐parameter character of grain boundaries with an area of over 3.4 × 106 nm2 in an abnormally grown nanocrystalline nickel sample. When coupled with existing theoretical simulation results, it is discerned that the grain boundary population shows a relatively large scatter when it is correlated to the calculated grain boundary energy; the grain boundaries of abnormally grown grains exhibit lower grain boundary energy compared to those that have not undergone abnormal growth. Merging high‐throughput grain boundary information obtained from three‐dimensional orientation mapping data with grain boundary properties derived from high‐throughput theoretical calculations following the concept of materials genome engineering will undoubtedly facilitate further advancements in comprehending and discerning the interfacial behaviors of crystalline materials.

Inelastic mechanical behaviour of an additively manufactured titanium alloy: a statistical continuum mechanics theory perspective

Statistical continuum mechanics theory was used to simulate the inelastic stress of polycrystalline materials using two-point statistics. For the experimental part, the Electron beam melting (EBM) technique (Arcam EBM Q10 additive machine) was used to fabricate cylindrical rods of Ti-6Al-4V both in horizontal and vertical directions. Electron backscatter diffraction (EBSD) technique was employed to achieve statistically reliable orientation maps of vertically and horizontally printed samples. In this study, high strain rate compression tests at six different strain rates were performed, and the stress–strain curves were generated. This work is amongst the first attempts to model the microstructure of additively manufactured hexagonal alloys under compressive loadings using the statistical continuum mechanics theory. The model is capable of simulating reasonably large microstructures (statistically representative) with a practical computational cost and accuracy, unlike numerical models that require a high computational cost. It should be noted that in additive manufacturing, due to large grains and high anisotropy, microstructures used in the simulations should be large enough to include sufficient information from the material’s structure. Therefore, using finite element models would be very challenging here. On the other hand, the statistical continuum mechanics theory uses the statistical representation of the material’s characteristics for solving the governing equations with Green’s function that enables this methodology to use more microstructure characteristic information without having a noticeable change to the computational cost. The proposed model in this study uses different microstructure characteristics such as crystal grain orientation, total slip systems, active slip systems, gain morphology, and chemical phases that are obtained from EBSD images for simulating the inelastic mechanical behavior of polycrystalline materials. Although this model simulates polycrystalline materials by considering various crystal and grain information, unlike numerical methods, it doesn’t simulate the grain interactions well and we cannot study local deformation and crack nucleation sites. This model works very well for simulating the overall behavior of material instead of each individual grain and failure analysis. This model has shown a good combination of computational cost and accuracy in which the error between the simulated and experimental strength for vertical and horizontal samples was 6.21% and 8.07%, respectively.

3D microscopy at the nanoscale reveals unexpected lattice rotations in deformed nickel.

In polycrystalline metals, plastic deformation is accompanied by lattice rotations resulting from dislocation glide. Following these rotations in three dimensions requires nondestructive methods that so far have been limited to grain sizes at the micrometer scale. We tracked the rotations of individual grains in nanograined nickel by using three-dimensional orientation mapping in a transmission electron microscope before and after in situ nanomechanical testing. Many of the larger-size grains underwent unexpected lattice rotations, which we attributed to a reversal of rotation during unloading. This inherent reversible rotation originated from a back stress-driven dislocation slip process that was more active for larger grains. These results provide insights into the fundamental deformation mechanisms of nanograined metals and will help to guide strategies for material design and engineering applications.

Crystal-orientation-dependent physical sputtering from four elemental metals

Physical sputtering and its dependence on crystal orientation is well-known, but crystallinity of the target is neither commonly considered in simulations nor when publishing experimental values for its yield. Due to the recent development of detector technology and therefore of crystal orientation mapping, a measuring technique has been established to obtain the physical sputtering yield for an extensive number of orientations of polycrystalline specimens. In this work, yields for two bcc metals (W and Mo) and two fcc metals (Cu and Pt) for impacting Ga ions with 30 keV and around 5 keV energy were determined experimentally and are compared with molecular dynamics (MD) simulations in a recently established two level approach and with binary collision approximation (BCA) simulations. The agreement between experimental yields and simulations is excellent regarding distribution in the angular space and reasonable regarding absolute values. As expected, the variation in angular space among the materials with the same crystal lattice structure is minor.

Advances in cellular and tissue-based imaging techniques for sarcoid granulomas.

Sarcoidosis embodies a complex inflammatory disorder spanning multiple systems, with its origin remaining elusive. It manifests as the infiltration of inflammatory cells that coalesce into distinctive noncaseous granulomas within afflicted organs. Unraveling this disease necessitates the utilization of cellular or tissue-based imaging methods to both visualize and characterize the biochemistry of these sarcoid granulomas. Although hematoxylin and eosin stain, standard in routine use alongside cytological stains have found utility in diagnosis within clinical contexts, special stains such as Masson's trichrome, reticulin, methenamine silver, and Ziehl-Neelsen provide additional varied perspectives of sarcoid granuloma imaging. Immunohistochemistry aids in pinpointing specific proteins and gene expressions further characterizing these granulomas. Finally, recent advances in spatial transcriptomics promise to divulge profound insights into their spatial orientation and three-dimensional (3-D) molecular mapping. This review focuses on a range of preexisting imaging methods employed for visualizing sarcoid granulomas at the cellular level while also exploring the potential of the latest cutting-edge approaches like spatial transcriptomics and matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI), with the overarching goal of shedding light on the trajectory of sarcoidosis research.

CPO and quantitative textural analyses within sheath folds

We investigate the intra- and inter-crystalline deformation processes involved in sheath fold development combining complementary fabric analysis techniques and 3D modelling by neutron tomography. The investigated sheath fold is a multi-layered sub-metre scale single-eye structure, developed in metapsammites from the Ben Hope Nappe, overlying the Moine Thrust Zone of NW Scotland. Crystallographic Preferred Orientations (CPOs) of quartz and biotite were acquired through a Neutron Diffractometer and an SEM-EBSD system to compare the full-fabric of the main phases and the active slip systems for an “in situ” structural control. Combined with orientation maps and grain size maps, results show that, despite the different structural positions of the investigated microdomains (upper vs lower fold limbs, inner vs outer sheath closures, distance from hinge of the sheath fold), quartz and biotite deformed uniformly, suggesting a constant differential stress and orientation of the kinematic vorticity axis. Previously recognized detachment horizons within the sampled sheath fold do not affect the fabric patterns recorded by quartz and biotite. This may be interpreted in two different ways: i) detachments formed during earlier active folding and prior to passive amplification of folds associated with more uniform flow to create the sheath fold geometries; ii) the quartz c-axis patterns are coeval with a late deformation phase (loading of the orogenic wedge) that pervasively obliterated the previous fabric and therefore did not preserve the active folding component. Several pieces of evidence reported here, such as top-to-SE normal-shear sense which is opposite to the regional kinematics, are more supportive of the second hypothesis. The analysis of mineral textures provides an improved dataset for the whole sheath fold and increases our understanding of recrystallization mechanisms active in shear zones.

3D Finger Rotation Estimation from Fingerprint Images

Various touch-based interaction techniques have been developed to make interactions on mobile devices more effective, efficient, and intuitive. Finger orientation, especially, has attracted a lot of attentions since it intuitively brings three additional degrees of freedom (DOF) compared with two-dimensional (2D) touching points. The mapping of finger orientation can be classified as being either absolute or relative, suitable for different interaction applications. However, only absolute orientation has been explored in prior works. The relative angles can be calculated based on two estimated absolute orientations, although, a higher accuracy is expected by predicting relative rotation from input images directly. Consequently, in this paper, we propose to estimate complete 3D relative finger angles based on two fingerprint images, which incorporate more information with a higher image resolution than capacitive images. For algorithm training and evaluation, we constructed a dataset consisting of fingerprint images and their corresponding ground truth 3D relative finger rotation angles. Experimental results on this dataset revealed that our method outperforms previous approaches with absolute finger angle models. Further, extensive experiments were conducted to explore the impact of image resolutions, finger types, and rotation ranges on performance. A user study was also conducted to examine the efficiency and precision using 3D relative finger orientation in 3D object rotation task.