Changes in seasonality of groundwater level fluctuations in a temperate-cold climate transition zone

In\ua0cold (i.e. boreal, subarctic, snowy)\ua0climate\ua0zones, dynamic\ua0groundwater\ua0storage is greatly affected by the timing and amount of snowmelt. With global warming, cold climates\ua0in\ua0the northern hemisphere will\ua0transition\ua0to temperate. As temperatures rise, the dominant type of precipitation will\ua0change\ua0from snow to rain\ua0in\ua0winter. Further, the growing season is prolonged. This has\ua0a\ua0direct impact on the aquifer recharge pattern. However, little is known about the effect of changing annual recharge regimes on\ua0groundwater\ua0storage. The present work deduces the impact of shifting\ua0climate\ua0zones on\ua0groundwater\ua0storage by evaluating the effect of\ua0climate\ua0seasonality\ua0on intra-annual hydraulic head\ua0fluctuations. The work compares intra-annual hydraulic head\ua0fluctuations\ua0in\ua0a\ua0temperate-cold\ua0climate\ua0transition\ua0zone\ua0(Fennoscandia) from two different periods (1980–1989, 2001–2010). This is done by associating rising vs. declining hydraulic heads with hydrometeorology. Due to the northwards migration of the temperate\ua0climate\ua0zone, there is\ua0a\ua0shift\ua0in\ua0seasonality\ua0between the two periods. This has\ua0a\ua0negative impact on\ua0groundwater\ua0levels, which are significantly lower\ua0in\ua02001–2010, particularly near the\ua0climate\ua0transition\ua0zone. The results demonstrate that increasing temperatures\ua0in\ua0cold\ua0climate\ua0regions may\ua0change\ua0the\ua0seasonality\ua0of\ua0groundwater\ua0recharge, by altering the main recharge period from being snowmelt-dominated (spring) to rain-dominated (winter). Additionally, this is connected to the duration of the growing season, which impedes\ua0groundwater\ua0recharge. The coupled effect of this on\ua0groundwater\ua0in\ua0the study area has led to\ua0a\ua0significant decrease\ua0in\ua0groundwater\ua0storage

Affective colormap design for accurate visual comprehension in industrial tomography

The design of colormaps can help tomography operators obtain accurate visual compre-hension, thereby assisting safety-critical decisions. The research presented here is about deploying colormaps that promote the best affective responses for industrial microwave tomography (MWT). To answer the two research questions related to our study, we firstly conducted a quantitative analysis of 11 frequently-used colormaps on a segmentation task. Secondly, we presented the same colormaps within a crowdsourced study comprising two parts to verify the quantitative outcomes. The first part encoded affective responses from participants into a prevailing four-quadrant valence–arousal grid; the second part recorded participant ratings towards the accuracy of each colormap on MWT segmentation. We concluded that three colormaps are the best suited in the context of MWT tasks. We also found that the colormaps triggering emotions in the positive–exciting quadrant can facilitate more accurate visual comprehension than other affect-related quadrants. A synthetic colormap design guideline was consequently proposed

Stochastic Volume Rendering of Multi-Phase SPH Data

In this paper, we present a novel method for the direct volume rendering of large smoothed‐particle hydrodynamics (SPH) simulation data without transforming the unstructured data to an intermediate representation. By directly visualizing the unstructured particle data, we avoid long preprocessing times and large storage requirements. This enables the visualization of large, time‐dependent, and multivariate data both as a post‐process and in situ. To address the computational complexity, we introduce stochastic volume rendering that considers only a subset of particles at each step during ray marching. The sample probabilities for selecting this subset at each step are thereby determined both in a view‐dependent manner and based on the spatial complexity of the data. Our stochastic volume rendering enables us to scale continuously from a fast, interactive preview to a more accurate volume rendering at higher cost. Lastly, we discuss the visualization of free‐surface and multi‐phase flows by including a multi‐material model with volumetric and surface shading into the stochastic volume rendering

Procedural Generation and Rendering of Realistic, Navigable Forest Environments: An Open-Source Tool

Simulation of forest environments has applications from entertainment and art creation to commercial and scientific modelling. Due to the unique features and lighting in forests, a forest-specific simulator is desirable, however many current forest simulators are proprietary or highly tailored to a particular application. Here we review several areas of procedural generation and rendering specific to forest generation, and utilise this to create a generalised, open-source tool for generating and rendering interactive, realistic forest scenes. The system uses specialised L-systems to generate trees which are distributed using an ecosystem simulation algorithm. The resulting scene is rendered using a deferred rendering pipeline, a Blinn-Phong lighting model with real-time leaf transparency and post-processing lighting effects. The result is a system that achieves a balance between high natural realism and visual appeal, suitable for tasks including training computer vision algorithms for autonomous robots and visual media generation.Comment: 14 pages, 11 figures. Submitted to Computer Graphics Forum (CGF). The application and supporting configuration files can be found at https://github.com/callumnewlands/ForestGenerato

Winding Roads: Routing edges into bundles

International audienceVisualizing graphs containing many nodes and edges efficiently is quite challenging. Drawings of such graphs generally suffer from visual clutter induced by the large amount of edges and their crossings. Consequently, it is difficult to read the relationships between nodes and the high-level edge patterns that may exist in standard node- link diagram representations. Edge bundling techniques have been proposed to help solve this issue, which rely on high quality edge rerouting. In this paper, we introduce an intuitive edge bundling technique which efficiently reduces edge clutter in graphs drawings. Our method is based on the use of a grid built using the original graph to compute the edge rerouting. In comparison with previously proposed edge bundling methods, our technique improves both the level of clutter reduction and the computation performance. The second contribution of this paper is a GPU-based rendering method which helps users perceive bundles densities while preserving edge color

Techniques de mise en scène pour le jeu vidéo et l'animation

Eurographics State of the Art Report (STAR).International audienceOver the last forty years, researchers in computer graphics have proposed a large variety of theoretical models and computer implementations of a virtual film director, capable of creating movies from minimal input such as a screenplay or storyboard. The underlying film directing techniques are also in high demand to assist and automate the generation of movies in computer games and animation. The goal of this survey is to characterize the spectrum of applications that require film directing, to present a historical and up-to-date summary of research in algorithmic film directing, and to identify promising avenues and hot topics for future research.Depuis quarante ans, les chercheurs en informatique graphique ont proposé une grande variété de modèles théoriques et d'implémentations de réalisateurs virtuels, capables de créer des films automatiquement à partir de scénarios ou de storyboards. Les techniques de mise en scène sous-jacentes peuvent également être très utiles pour assister et automatiser la création de films dans le jeu vidéo et l'animation. Le but de cet état de l'art est de caractériser le spectre des applications qui peuvent bénéficier des techniques de mise en scène, de donner un compte rendu historique de la recherche en mise en scène algorithmique, et d'identifier les tendances et perspectives du domaine