Neural Lens Modeling

Recent methods for 3D reconstruction and rendering increasingly benefit from end-to-end optimization of the entire image formation process. However, this approach is currently limited: effects of the optical hardware stack and in particular lenses are hard to model in a unified way. This limits the quality that can be achieved for camera calibration and the fidelity of the results of 3D reconstruction. In this paper, we propose NeuroLens, a neural lens model for distortion and vignetting that can be used for point projection and ray casting and can be optimized through both operations. This means that it can (optionally) be used to perform pre-capture calibration using classical calibration targets, and can later be used to perform calibration or refinement during 3D reconstruction, e.g., while optimizing a radiance field. To evaluate the performance of our proposed model, we create a comprehensive dataset assembled from the Lensfun database with a multitude of lenses. Using this and other real-world datasets, we show that the quality of our proposed lens model outperforms standard packages as well as recent approaches while being much easier to use and extend. The model generalizes across many lens types and is trivial to integrate into existing 3D reconstruction and rendering systems.Comment: To be presented at CVPR 2023, Project webpage: https://neural-lens.github.i

Neural Assets: Volumetric Object Capture and Rendering for Interactive Environments

Creating realistic virtual assets is a time-consuming process: it usually involves an artist designing the object, then spending a lot of effort on tweaking its appearance. Intricate details and certain effects, such as subsurface scattering, elude representation using real-time BRDFs, making it impossible to fully capture the appearance of certain objects. Inspired by the recent progress of neural rendering, we propose an approach for capturing real-world objects in everyday environments faithfully and fast. We use a novel neural representation to reconstruct volumetric effects, such as translucent object parts, and preserve photorealistic object appearance. To support real-time rendering without compromising rendering quality, our model uses a grid of features and a small MLP decoder that is transpiled into efficient shader code with interactive framerates. This leads to a seamless integration of the proposed neural assets with existing mesh environments and objects. Thanks to the use of standard shader code rendering is portable across many existing hardware and software systems

Energy changes in the chemical reactions of elements with hydrochloric acid and with hydrogen peroxide

Namen naloge je bila opredelitev reakcije posameznega elementa v elementarnem stanju s koncentrirano klorovodikovo kislino kot endotermno ali eksotermno in opredelitev reakcije posameznega elementa v elementarnem stanju z vodikovim peroksidom kot endotermno ali eksotermno. Kemijske reakcije sem izvajal v digestoriju, kjer sem s pomočjo Vernierjevega vmesnika spremljal spreminjanje temperature v določenem časovnem intervalu. Reakcije sem izvajal z vsemi elementi, ki so bili na voljo v laboratoriju, zajel pa sem tako skupino kovin in nekovin kot skupino polkovin. Reakcije so potekale pri približno enakih pogojih. V nalogi sem predstavil lastnosti posameznih elementov iz skupine kovin, polkovin in nekovin ter s primeri preproste razlage spreminjanja energije pri kemijskih reakcijah skušal predlagati učiteljem, kako se lotiti usvajanja te snovi v razredu. Z rezultati naloge sem želel izpostaviti najbolj tipične eksotermne in endotermne reakcije elementov s kislino ali peroksidom, ki sicer niso tako pogosti pri obravnavanju snovi v šolah, a vendar so v naravi prisotni in uporabni. S tem sem želel spodbuditi učitelje k obravnavi v šoli.The purpose od this dissertation was to define the reaction of a particular element in the elementary state with concentrated hydrochloric acid as endothermic or exothermicand to define the reaction of an element in the elementary state with hydrogen peroxide as endothermic or exothermic. I monitored the temperature change in time interval 10 minutes. The reactions took place under approximately the same conditions. With the results of the dissertation, I wanted to highlight the most typical exothermic and endothermic reactions of the elements with acid or peroxide, which are not so common in dealing with substances in schools, but they are naturally present and useful, and thus wanted to encourage teachers to be treated at school

Where should the label for a polygon be placed?

V magistrskem delu se najprej seznanimo s trilinearnimi in baricentričnimi koordinatami. Nato spoznamo izotomično in izogonalno transformacijo. Po uvodnih pojmih je podrobneje opisan problem, ki ga rešujemo postopoma. Začnemo z najenostavnejšimi liki, katerih geometrijo dokaj dobro poznamo. Pri iskanju točke, ki bi bila primerna za postavitev oznake večkotnika, naletimo na ogromno kandidatov, vendar se izkaže, da jih ima večina določene pomanjkljivosti. Po opisanem postopku iskanja primerne točke in nekaj primerih se zopet vrnemo k trikotniku saj določimo algoritem, ki nas za poljubni večkotnik pripelje do točke, kjer moramo poiskati primerno točko ravno v trikotniku. Tu se srečamo s trikotniku včrtanimi elipsami in najbolj značilne tudi opišemo. Posebej obravnavamo tudi Lemoinovo elipso in Spiekerjevo točko, kar je tudi rešitev našega problema.In the following master thesis we first learn about trilinears, barycentrics. Then we describe isotomic and isogonal conjugate. After describing the main problem, we start searching for the most optimal place for placing laber for a polygon. We start with triangle and quadrilateral and we find out, that a lot of possible candidates (points) have some imperfections. According to the procedure described for a suitable point and some examples, we return to the triangle again since we define an algorithm that leads us to conclusion that a point for placing a label for general polygon is a point in triangle which we get as result of algorithm. We consider ellipses inscribed in the triangle and some triangle centres related to these ellipses. At the end we show results related to Lemoine ellipse and Spieker centre, which are closely connected with the final step of the solution to our problem

Vpliv zaviralcev JAK na inzulinsko signalizacijo v skeletnih mišicah

JAK-STAT signalna pot je povezana z inzulinsko signalizacijo. Inhibicija kinaze JAK s kompetitivnima inhibitorjema ruksolitinibom in tofacitinibom na mestu vezave ATP bi tako lahko spremenila aktivacijo inzulinskih signalnih poti PI3K/Akt in MEK/ERK. Vpliv na inzulinsko signalizacijo ima tudi interlevkin-6 prek inhibicije pomembnega proteina za prenos inzulinskega signala znotraj celice IRS. Kronična inhibicija signala lahko vodi v razvoj inzulinske rezistence, za katero so najbolj dovzetne prav skeletnomišične celice, ki privzamejo največji delež glukoze. Povišana koncentracija STAT3 je povezana z razvojem inzulinske rezistence in sladkorne bolezni tipa 2. Zato nas je zanimal vpliv inhibitorjev JAK na občutljivost in odzivnost proteinov Akt, AS160 in Erk1/2 na inzulinsko signalizacijo. Zanimal nas je tudi odziv ob dodatku visoke koncentracije interlevkina-6. Primerjali smo aktivnosti proteinov Akt, AS160 in Erk1/2 v bazalnih pogojih, ob dodatku inzulina in ob dodatku inhibitorja JAK. Primerjali smo tudi aktivnost istih proteinov ob akutnem in kroničnem delovanju interlevkina-6 ter ob sočasnem delovanju inzulina in akutnem in kroničnem delovanju inhibitorjev JAK. Poskuse smo izvedli na podganjih (L6) mišičnih cevčicah in za analizo fosforilacije proteinov uporabili metodo prenos western. Potrdili smo, da ruksolitinib poveča občutljivost in odzivnost skeletnomišičnih celic na inzulin v bazalnih pogojih. V prisotnosti interlevkina-6 sta ruksolitinib in tofacitinib rahlo povečala aktivacijo signalne poti Akt/AS160 in pri istih pogojih ne vplivata na aktivacijo signalne poti Erk1/2.JAK-STAT signaling pathway is integrated with insulin signalisation. JAK inhibition by competitive ATP inhibitors Ruxolitinib and Tofacitinib could influence the activation of insulin signaling pathways PI3K/Akt/AS160 and MEK/ERK. Interleukin-6 also influences the insulin signalisation by inhibiting IRS and blocking the signal transduction inside the cell. Chronic inhibition can lead to insulin resistance, especially in skeletal muscle cells which have a very high glucose consumption. High concentration of STAT3 is linked to insulin resisatance and type 2 diabetes. We wandered how JAK inhibitors influence the responsivnes of Akt, AS160 and Erk1/2 on insulin stimulation. We also wanted to know how interleukin-6 in high concentrarion influences the same proteins. We compared the phosphorilation of Akt, AS160 and Erk1/2 in basal conditions, with insulin and with JAK inhibitor. We also compared phosphorilation of the same proteins with the addition of interleukin-6, insulin and JAK inhibitors. The experiments were preformed on L6 myotubes and western blotting was used for protein phosphorilation analasys. We confirmed that Ruxolitinib increases the responsivnes of skeletal muscle cells on insulin signalisation in basal conditions. With the addition of high concentration of interleukin-6 Ruxolitinib and Tofacitinib slightly increased the activation of Akt/AS160 signaling pathway, but did not influence the Erk1/2 signaling pathway