671 research outputs found
RENDERING STOCHASTIC & ACCUMULATION BUFFER UNTUK EFEK MOTION BLUR PADA ENGINE OGRE 3D
Sebuah foto dari obyek yang bergerak dengan cepat akan menghasilkan efek motion blur. Sebaliknya, seluruh hasil proses render komputer grafis akan menghasilkan gambar yang tajam. Untuk menghasilkan hasil proses render yang realis, dibutuhkan efek motion blur. Banyak pendekatan dilakukan untuk menghasilkan efek motion blur, antara lain accumulation buffer, post- process motion blur, dan metode stochastic. Dalam jurnal ini, kami mengembangkan serta membandingkan motion blur pada engine OGRE 3D. Metode yang digunakan adalah accumulation buffer dan metode stochastic. Dibandingkan dengan metode accumulation buffer, metode stochastic dapat mengurangi artifak bergaris yang dihasilkan metode accumulation buffer. Namun metode stochastic dapat menghasilkan noise acak.
Kata Kunci: Motion blur, stochastic rendering, accumulation butter, OGRE 3D engine
Spectral reflectance and transmittance prediction model for stacked transparency and paper both printed with halftone colors
International audienceWhen a transparency printed with a first halftone color is deposited on top of a paper printed with a second halftone color, we obtain a third color that we are able to predict in both reflectance and transmittance modes, thanks to a spectral prediction model. The model accounts for the multiple reflections of light between the printed paper and the printed transparency, which are themselves described by specific reflectance and transmittance models, each one being calibrated using a small number of printed colors. The model can account for light scattering by the inks. The measuring geometry and the orientations of light in the transparency are taken into account on the basis of radiometric rules and geometrical optical laws. Experimental testing carried out from several inkjet-printed CMY halftones shows fairly good agreement between predictions and measurements
Spectral transmittance model for stacks of transparencies printed with halftone colors
International audienceThe present work investigates the transmission of light through stacks of halftone printed transparencies. We propose a spectral transmittance model describing the multiple reflections of light between the transparencies, whose individual reflectance and transmittance have themselves been obtained by a prediction model. The model for single printed transparency involves the multiple reflections of light between the interfaces as well as the orientation-dependent attenuations of light within the plastic and ink layers. A procedure enables converting the nominal ink surface coverages into effective ones by taking into account the spreading of the inks. Calibration of the model is based on printing a small number of color patches on one transparency and measuring their spectral transmittance. Regarding the stacks of transparencies, an experimental test carried out with inkjet printed samples shows good agreement between predictions and measurements for stacks of two, three and four transparencies. Stochastic halftones are used in order to avoid the apparition of moiré patterns when superposing the halftones. By inversion of the model, we are able to determine the halftone colors to print on each transparency in order to obtain by superposition one targeted color. An original application of this, called "color matching", consists in producing one color of stack from various combinations of colors on the transparencies. The prediction accuracy of the proposed model guarantees the good visual uniformity of the resulting colored area
Orbital Multiferroicity in Pentalayer Rhombohedral Graphene
Ferroic orders describe spontaneous polarization of spin, charge, and lattice
degrees of freedom in materials. Materials featuring multiple ferroic orders,
known as multiferroics, play important roles in multi-functional electrical and
magnetic device applications. 2D materials with honeycomb lattices offer
exciting opportunities to engineer unconventional multiferroicity, where the
ferroic orders are driven purely by the orbital degrees of freedom but not
electron spin. These include ferro-valleytricity corresponding to the electron
valley and ferro-orbital-magnetism supported by quantum geometric effects. Such
orbital multiferroics could offer strong valley-magnetic couplings and large
responses to external fields-enabling device applications such as
multiple-state memory elements, and electric control of valley and magnetic
states. Here we report orbital multiferroicity in pentalayer rhombohedral
graphene using low temperature magneto-transport measurements. We observed
anomalous Hall signals Rxy with an exceptionally large Hall angle (tan{\Theta}H
> 0.6) and orbital magnetic hysteresis at hole doping. There are four such
states with different valley polarizations and orbital magnetizations, forming
a valley-magnetic quartet. By sweeping the gate electric field E we observed a
butterfly-shaped hysteresis of Rxy connecting the quartet. This hysteresis
indicates a ferro-valleytronic order that couples to the composite field E\cdot
B, but not the individual fields. Tuning E would switch each ferroic order
independently, and achieve non-volatile switching of them together. Our
observations demonstrate a new type of multiferroics and point to electrically
tunable ultra-low power valleytronic and magnetic devices
Face recognition system using fringe projection and moiré: characterization with fractal parameters
We show a new method for face recognition which combines the projection of structures with different characteristics (fringes, bars or grids, dots or speckle) over the face. These projections will then allow the creation of a computer-generated moiré pattern over which different kinds of fractal and complex geometry parameters are then measured. Such parameters will then be used as inputs for a neuro-symbolic hybrid system. Here, we analyze the incidence of some parameters on the efficience for the face recognition method
Atomistic modeling of the directed-assembly of bimetallic Pt-Ru nanoclusters on Ru(0001)-supported monolayer graphene
The formation of Pt-Ru nanoclusters (NCs) by sequential deposition of Pt and Ru on a periodically rumpled graphene sheet supported on Ru(0001) is analyzed by atomistic-level modeling and kinetic Monte Carlo simulations. The “coarse-scale” periodic variation of the adsorption energy of metal adatoms across the graphene sheet directs the assembly of NCs to a periodic array of thermodynamically preferred locations. The modeling describes not only just the NC densities and size distributions, but also the composition distribution for mixed NCs. A strong dependence of these quantities on the deposition order is primarily related to different effective mobilities of Pt and Ru on the supported graphene
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