Scalable Real-Time Rendering for Extremely Complex 3D Environments Using Multiple GPUs

In 3D visualization, real-time rendering of high-quality meshes in complex 3D environments is still one of the major challenges in computer graphics. New data acquisition techniques like 3D modeling and scanning have drastically increased the requirement for more complex models and the demand for higher display resolutions in recent years. Most of the existing acceleration techniques using a single GPU for rendering suffer from the limited GPU memory budget, the time-consuming sequential executions, and the finite display resolution. Recently, people have started building commodity workstations with multiple GPUs and multiple displays. As a result, more GPU memory is available across a distributed cluster of GPUs, more computational power is provided throughout the combination of multiple GPUs, and a higher display resolution can be achieved by connecting each GPU to a display monitor (resulting in a tiled large display configuration). However, using a multi-GPU workstation may not always give the desired rendering performance due to the imbalanced rendering workloads among GPUs and overheads caused by inter-GPU communication. In this dissertation, I contribute a multi-GPU multi-display parallel rendering approach for complex 3D environments. The approach has the capability to support a high-performance and high-quality rendering of static and dynamic 3D environments. A novel parallel load balancing algorithm is developed based on a screen partitioning strategy to dynamically balance the number of vertices and triangles rendered by each GPU. The overhead of inter-GPU communication is minimized by transferring only a small amount of image pixels rather than chunks of 3D primitives with a novel frame exchanging algorithm. The state-of-the-art parallel mesh simplification and GPU out-of-core techniques are integrated into the multi-GPU multi-display system to accelerate the rendering process

Ellic’s Exercise Class: An Active VR Game for Fitness

In this work, we present an active VR game called Ellic’s Exercise Class . Ellic is a cartoonish elephant who will guide the players during the gameplay. This game is a set of seven mini exercise games, including blocking, goalkeeper, volleyball, archery, skeet, baseball, and shooter. Each game has three difficulty levels: beginner, professional, and master. Players can choose the best difficulty level for them based on their skills. Fig. 1 shows the screenshots for the gameplay of the blocking, volleyball, and archery. The goal of our game is to let players have some exercises while playing games and encourage them to gain the interest of exercising. All the moveable components in our game scene are implemented based on physical simulation. The players can interact with these objects by the movement of their bodies. The game requires the player to move full body to interact with sporting gameplay events

Lunar Roving Adventure: A Serious VR Game of Lunar Exploration Missions

In this work, we present a serious VR game named Lunar Roving Adventure. This game is based on the activities of the Apollo 16 lunar exploration mission in the 1970s. In the Apollo 16 mission, astronauts landed on the Moon and drove the lunar rover. The goal of this game is to motivate them to learn more about the lunar exploration missions and gain interest in space science. The game includes three gaming phases: planning, preparing, and driving. The screenshots of the three gaming phases are shown in Fig. 1. In the Planning phase, the player plans and creates the route of the mission by placing tokens on a 3D lunar terrain map. They need to learn to use the coordinate system and do some calculations. In the Preparing phase, the player selects and loads devices onto the lunar rover based on the requirements of the mission. In the Driving phase, the player drives the rover through all the stop stations to the end of the route. They need to operate the navigation devices to determine the direction. They also need to control the speed to avoid overheating problems. As shown in Fig. 2, the lunar terrain is converted from the Lunar Reconnaissance Orbiter (LRO) data of Descartes Highlands. That was the place where the real Apollo 16 Lunar Module landed

Real-Time Large Crowd Rendering with Efficient Character and Instance Management on GPU

Achieving the efficient rendering of a large animated crowd with realistic visual appearance is a challenging task when players interact with a complex game scene. We present a real-time crowd rendering system that efficiently manages multiple types of character data on the GPU and integrates seamlessly with level-of-detail and visibility culling techniques. The character data, including vertices, triangles, vertex normals, texture coordinates, skeletons, and skinning weights, are stored as either buffer objects or textures in accordance with their access requirements at the rendering stage. Our system preserves the view-dependent visual appearance of individual character instances in the crowd and is executed with a fine-grained parallelization scheme. We compare our approach with the existing crowd rendering techniques. The experimental results show that our approach achieves better rendering performance and visual quality. Our approach is able to render a large crowd composed of tens of thousands of animated instances in real time by managing each type of character data in a single buffer object

Experiments on the gas production of brown coal degraded by exogenous methanogens

To investigate the ability of exogenous bacteria to degrade brown coal, methanogens were enriched from anaerobic sludge and domesticated using brown coal as carbon source. After domestication, the lag time of initial gas production is shortened from 12 to 6 days and the CH4 production increased by 29.2% in 30 days. The generated biogas is composed of CH4 and a little CO2, no heavy hydrocarbons are detected. Experiments on gas production influencing factors demonstrate that the best initial pH for the culture medium is 7.0 and the maximum gas production is 1.9 times and 2.4 times higher than that at pH 6.4 and pH 7.4, respectively. The particle size of coal is one of factors influencing the gas production: the general trend is the smaller the particle size, the bigger the gas production, but the variation of gas production is not significant with decreasing particle size. Gas produced by the culture medium accounts for around 50% of the total gas production and it is likely caused by the addition of L-cysteine (0.5 g/L) and yeast extract (1 g/L) to the medium. Key words: methanogen, brown coal, exogenous bacteria, domestication, coal-derived ga

Optical fiber magnetic field sensor based on magnetic fluid and microfiber mode interferometer

A magnetic field sensor is proposed based on the combination of magnetic fluid (MF) and an optical microfiber mode interferometer (MMI). It is measured that the MMI is highly sensitive to ambient refractive index (RI) with a high sensitivity up to 16,539 nm/RIU while RI of the MF is changeable with an external magnetic field strength. By monitoring wavelength shift of transmission spectrum of the MMI, magnetic field measurement is realized with a maximum sensitivity of −293 pm/Oe in the range of 0–220 Oe.Accepted versio

Relative Humidity Sensor Based on Microfiber Loop Resonator

A novel relative humidity (RH) sensor based on a microfiber loop resonator (MLR) is proposed and experimentally demonstrated. As refractive index of the microfiber in the MLR is modified by environmental humidity, resonant wavelength of the MLR changes with RH level. By detecting this wavelength shift, RH measurement is realized with a linear response sensitivity of 1.8 pm/% RH. The obvious advantage of this technique over others is that no coating of humidity-sensitive material is required

3D Forest Mapping Using A Low-Cost UAV Laser Scanning System: Investigation and Comparison

Automatic 3D forest mapping and individual tree characteristics estimation are essential for forest management and ecosystem maintenance. The low-cost unmanned aerial vehicle (UAV) laser scanning (ULS) is a newly developed tool for cost-effectively collecting 3D information and attempts to use it for 3D forest mapping have been made, due to its capability to provide 3D information with a lower cost and higher flexibility than the standard ULS and airborne laser scanning (ALS). As the direct georeferenced point clouds may suffer from distortion caused by the poor performance of a low-cost inertial measurement unit (IMU), and 3D forest mapping using low-cost ULS poses a great challenge. Therefore, this paper utilized global navigation satellite system (GNSS) and IMU aided Structure-from-Motion (SfM) for trajectory estimation, and, hence, overcomes the poor performance of low-cost IMUs. The accuracy of the low-cost ULS point clouds was compared with the ground truth data collected by a commercial ULS system. Furthermore, the effectiveness of individual trees segmentation and tree characteristics estimation derived from the low-cost ULS point clouds were accessed. Experiments were undertaken in Dongtai forest farm, Yancheng City, Jiangsu Province, China. The results showed that the low-cost ULS achieved good point clouds quality from visual inspection and comparable individual tree segmentation results (P = 0.87, r = 0.84, F = 0.85) with the commercial system. Individual tree height estimation performed well (coefficient of determination (R2) = 0.998, root-mean-square error (RMSE) = 0.323 m) using the low-cost ULS. As for individual tree crown diameter estimation, low-cost ULS achieved good results (R2 = 0.806, RMSE = 0.195 m) after eliminating outliers. In general, such results illustrated the high potential of the low-cost ULS in 3D forest mapping, even though 3D forest mapping using the low-cost ULS requires further research