Ambient Obsurance Baking on the GPU

Ambient Occlusion and Ambient Obscurance are coarse approximations to global illumination from ambient lighting, commonly used in film and games. This paper describes a system that computes Ambient Obscurance over the vertices of complex polygon meshes. Novel contributions include pre-processing necessary for “triangle soup” scene representations to minimize artifacts, a compact model for different classes of instanced decorator objects such as trees and shrubs, a compact model for pre-computed visibility to be used on dynamically placed objects, and an approximation to model the occlusion of small decorator objects when ray tracing

Crowd simulation in an emergency situation

Los planes de evacuación de diferentes edificios, barcos y cualquier otro tipo de sitios públicos es difícil de definir, al menos, si quieres que sea lo más eficiente, seguro y rápido posible. El proyecto trata de simular un espacio virtual con avatares ficticios y un usuario que intentarán salir.The evacuation plan for different buildings, ships and all kind of public spaces is hard to define, at least, if you want it to be the most efficient plan, thus the safest and the fastest. Therefore, the project is about simulating an environment with virtual avatars trying to find the way out

A high-pressure hydrogen time projection chamber for the MuCap experiment

The MuCap experiment at the Paul Scherrer Institute performed a high-precision measurement of the rate of the basic electroweak process of nuclear muon capture by the proton, $\mu^- + p \rightarrow n + \nu_\mu$. The experimental approach was based on the use of a time projection chamber (TPC) that operated in pure hydrogen gas at a pressure of 10 bar and functioned as an active muon stopping target. The TPC detected the tracks of individual muon arrivals in three dimensions, while the trajectories of outgoing decay (Michel) electrons were measured by two surrounding wire chambers and a plastic scintillation hodoscope. The muon and electron detectors together enabled a precise measurement of the $\mu p$ atom's lifetime, from which the nuclear muon capture rate was deduced. The TPC was also used to monitor the purity of the hydrogen gas by detecting the nuclear recoils that follow muon capture by elemental impurities. This paper describes the TPC design and performance in detail.Comment: 15 pages, 13 figures, to be submitted to Eur. Phys. J. A; clarified section 3.1.2 and made minor stylistic corrections for Eur. Phys. J. A requirement

Interactive Sculpting of Digital Faces Using an Anatomical Modeling Paradigm

Digitally sculpting 3D human faces is a very challenging task. It typically requires either 1) highly-skilled artists using complex software packages for high quality results, or 2) highly-constrained simple interfaces for consumer-level avatar creation, such as in game engines. We propose a novel interactive method for the creation of digital faces that is simple and intuitive to use, even for novice users, while consistently producing plausible 3D face geometry, and allowing editing freedom beyond traditional video game avatar creation. At the core of our system lies a specialized anatomical local face model (ALM), which is constructed from a dataset of several hundred 3D face scans. User edits are propagated to constraints for an optimization of our data-driven ALM model, ensuring the resulting face remains plausible even for simple edits like clicking and dragging surface points. We show how several natural interaction methods can be implemented in our framework, including direct control of the surface, indirect control of semantic features like age, ethnicity, gender, and BMI, as well as indirect control through manipulating the underlying bony structures. The result is a simple new method for creating digital human faces, for artists and novice users alike. Our method is attractive for low-budget VFX and animation productions, and our anatomical modeling paradigm can complement traditional game engine avatar design packages

Towards High Fidelity Monocular Face Reconstruction with Rich Reflectance using Self-supervised Learning and Ray Tracing

Robust face reconstruction from monocular image in general lighting conditions is challenging. Methods combining deep neural network encoders with differentiable rendering have opened up the path for very fast monocular reconstruction of geometry, lighting and reflectance. They can also be trained in self-supervised manner for increased robustness and better generalization. However, their differentiable rasterization based image formation models, as well as underlying scene parameterization, limit them to Lambertian face reflectance and to poor shape details. More recently, ray tracing was introduced for monocular face reconstruction within a classic optimization-based framework and enables state-of-the art results. However optimization-based approaches are inherently slow and lack robustness. In this paper, we build our work on the aforementioned approaches and propose a new method that greatly improves reconstruction quality and robustness in general scenes. We achieve this by combining a CNN encoder with a differentiable ray tracer, which enables us to base the reconstruction on much more advanced personalized diffuse and specular albedos, a more sophisticated illumination model and a plausible representation of self-shadows. This enables to take a big leap forward in reconstruction quality of shape, appearance and lighting even in scenes with difficult illumination. With consistent face attributes reconstruction, our method leads to practical applications such as relighting and self-shadows removal. Compared to state-of-the-art methods, our results show improved accuracy and validity of the approach

Mars Activities: Teacher Resources and Classroom Activities

This set of classroom activities presents the challenges of operating a planetary rover, how to construct a scale model of the Earth-Moon system, how Martian surface core samples can be identified and what they tell us about Mars. Each activity comes with clearly delineated instructions, associated standards, guides and worksheets, and enhancement materials. Educational levels: High school, Intermediate elementary, Middle school, Primary elementary

Fabricating Suspended Carbon Structures Using SU-8 Photolithography

The phenomenon of T-topping has been deemed as an imperfection of the SU-8 photolithography process, due to light diffraction, overexposure of the SU-8, and other process parameters. The first objective of this work is to demonstrate that T-topping can be used as a microfabrication resource to produce suspended structures between photo-patterned high aspect ratio SU-8 posts, as precursors for carbon wires (width\u3e1µm) and bridges (width\u3e1µm). Such carbon structures could be used in a number of applications, such as the fabrication of nanowire based biosensors for the medical and food industry. The second objective is to develop a model able to predict what type of structures will be featured by an array of SU-8 posts, and in case of suspended structures, their length and width, in function of the particular choice of process parameters. The parameters examined are: type of contact, exposure time, type of gap, nominal size and nominal gap. A variety of suspended structures are obtained, and repeatable carbon wires of diameter as low as 800nm can be fabricated with the right choice of parameters. Given a choice of the parameters, the model proposed succeeds into predicting the presence and length of posts of hexagonal, squared and circular shape, but fails in calculating their width. The model needs future work to reliably calculate the width of the suspended structures, and needs to be calibrated for triangles and diamonds. Also, the SU-8 thickness will have to be integrated in the model

Dynamic Relationships Among Selected U.S. Commodity-Based, Value Added Markets: Applying Directed Acyclic Graphs to a Time Series Model

This paper demonstrates the application of a recently developed methodology, the combination of directed acyclic graphs (DAGs) with Bernanke structural vector autoregression (VAR) models, to model a system of U.S. commodity-related and value-added markets. As an example, the paper applies this methodology to a quarterly system of U.S. markets: the wheat market and a set of downstream milling and bakery markets that use wheat as an input. Analyses of the model's impulse response simulations and forecast error variance decompositions provide updated estimates of market elasticity parameters that drive these markets, and updated policy-relevant information on how these quarterly markets run and dynamically interact. Results suggest that movements in commodity-based markets strongly influence each other, although most of these effects occur in the long run beyond a single crop cycle. The paper illuminates how important U.S. food prices respond to wheat farm market shocks in price and quantity.Bernanke structural VARs, directed acyclic graphs, quarterly wheat-related markets, Industrial Organization, Marketing, Research Methods/ Statistical Methods,

Stylized medieval village modular 3D asset package

This document describes and explains the process of developing a three-dimensional stylized medieval village asset package. The pack is modular, so lots of different combinations are possible. Meshes, textures, materials, and scenes are all created from scratch. The project results into an asset package with more than 140 unique meshes, several materials and material instances that allow to change several parameters, some prefabs, as well as two example scenes, one to show the deployed props and the other with a ready-to-play scene with already constructed buildings and street decorations placed. Though this document, the objectives, research, some analysis, along with the management and planning of the project, are explained. Then, there is the development process, where the techniques and procedures used for the package are described. This step goes from the modeling of the first meshes, through creating procedural materials, the adaptation of the tool into Unreal Engine 4 and the different problems and difficulties encountered during the whole development process. Once the project was finished, it was concluded that it could be good to adapt the package into Unity Engine, in conjunction with a wider variety of props and materials as well as resolving bugs, errors, and add possible improvements