This thesis deals with rendering of large scale terrain. The first part describes theory of terrain rendering and particular level of detail techniques. Three modern intriguing algorithms are briefly depicted after this theoretical part. Main work insists on description of Geometry Clipmaps algorithm along with its optimized version GPU-Based Geometry Clipmaps. Implementation of this optimized algorithm is depicted in detail. Main advantage of this approach is incremental update of vertex data, which allows to offload overhead from CPU to GPU. In the last chapter performance of my implementation is analysed using simple benchmark.

Realistic models of landscapes are frequently needed for 3D renderings, VFX work or video games. However, modelling landscapes can be a complicated and labour-intensive task, and for this reason many algorithms have been proposed to automate the process. Among the many possible ways to create a synthetic landscape, the most common one is to simulate the various types of erosions (e.g. erosion caused by glaciers and rivers) that create real eroded landscapes, like the Grand Canyon. Many solutions have been published to simulate such terrain erosion processes in computer graphics. However the authors usually only focus on recreating a landscape at geometry level, and ignore the shading level. But surface colours and textures that match the coarse geometric features created by the erosion simulation are also essential ingredients for a believable result. And obtaining detailed surface textures by running a simulation that is able to catch all the micro-details involved is usually technically infeasible due to the involved complexity. The method that we propose attempts to get around this barrier by applying suitable detail shaders to the results of a coarse-grid erosion simulation. Specifically, we will work with a dictionary of pre-generated shaders for landscape appearance: these will be both "plain" colour...

<p>Captured and generated 3D data can be so large that it creates a problem for today's computers since they do not fit into the main or graphics card memory. Therefore methods for handling and rendering the data must be developed. This thesis presents a way to pre-process and render out-of-core height map data for real time use. The pre-processing uses a mesh decimation API called Simplygon developed by Donya Labs to optimize the geometry. From the height map a normal map can also be created and used at render time to increase the visual quality. In addition to the 3D data textures are also supported. To decrease the time to load an object the normal and texture maps can be compressed on the graphics card prior to rendering. Three different methods for covering gaps are explored of which one turns out to be insufficient for rendering cylindrical equidistant projected data.At render time two threads work in parallel. One thread is used to page the data from the hard drive to the main and graphics card memory. The other thread is responsible for rendering all data. To handle precision errors caused by spatial difference in the data each object receives a local origin and is then rendered relative to the camera. An atmosphere which handles views from both space and ground is computed on the graphics card.The result is an application adapted to current graphics card technology which can page out-of-core data and render a dataset covering the entire earth at 500 meters spatial resolution with a realistic atmosphere.</p>

<p>Simulation of modern battlefield scenarios on consumer PC:s deal with a number of limitations, many of them related to the limited performance of a normal PC compared to workstations and servers. Specifically, the visualization of realistic large scale outdoor environments is problematic because of the large amount of data required to describe its contents. This becomes especially problematic in simulations of fast moving vehicles such as aircrafts, where one needs to maintain high frame rates while having high visual detail for orientation and targeting. This thesis proposes a method of generating realistic outdoor environments from actual geological data and then rendering it efficiently using an improved level of detail algorithm within a proprietary battle simulation framework. We also show how to integrate an open source Flight Dynamics Model (FDM) into the simulation framework for future hybrid simulations involving aircrafts.</p>

Captured and generated 3D data can be so large that it creates a problem for today's computers since they do not fit into the main or graphics card memory. Therefore methods for handling and rendering the data must be developed. This thesis presents a way to pre-process and render out-of-core height map data for real time use. The pre-processing uses a mesh decimation API called Simplygon developed by Donya Labs to optimize the geometry. From the height map a normal map can also be created and used at render time to increase the visual quality. In addition to the 3D data textures are also supported. To decrease the time to load an object the normal and texture maps can be compressed on the graphics card prior to rendering. Three different methods for covering gaps are explored of which one turns out to be insufficient for rendering cylindrical equidistant projected data.At render time two threads work in parallel. One thread is used to page the data from the hard drive to the main and graphics card memory. The other thread is responsible for rendering all data. To handle precision errors caused by spatial difference in the data each object receives a local origin and is then rendered relative to the camera. An atmosphere which handles views from both space and ground is computed on the graphics card.The result is an application adapted to current graphics card technology which can page out-of-core data and render a dataset covering the entire earth at 500 meters spatial resolution with a realistic atmosphere.

Simulation of modern battlefield scenarios on consumer PC:s deal with a number of limitations, many of them related to the limited performance of a normal PC compared to workstations and servers. Specifically, the visualization of realistic large scale outdoor environments is problematic because of the large amount of data required to describe its contents. This becomes especially problematic in simulations of fast moving vehicles such as aircrafts, where one needs to maintain high frame rates while having high visual detail for orientation and targeting. This thesis proposes a method of generating realistic outdoor environments from actual geological data and then rendering it efficiently using an improved level of detail algorithm within a proprietary battle simulation framework. We also show how to integrate an open source Flight Dynamics Model (FDM) into the simulation framework for future hybrid simulations involving aircrafts.

This master's thesis deals with terrain rendering using a modern algorithm for adaptive level of detail. It describes two currently most used graphical application interfaces and high-level libraries that use them and summarizes principles and features of several level-of-detail algorithms for terrain rendering. In more detail it then describes the implementation of Seamless patches for GPU-based terrain rendering algorithm.

While modern digital entertainment has seen a major shift toward photorealism in animation, there is still significant demand for stylized rendering tools. Stylized, or non-photorealistic rendering (NPR), applications generally sacrifice physical accuracy for artistic or functional visual output. Oftentimes, NPR applications focus on extracting specific features from a 3D environment and highlighting them in a unique manner. One application of interest involves recreating 2D hand-drawn art styles in a 3D-modeled environment. This task poses challenges in the form of spatial coherence, feature extraction, and stroke line rendering. Previous research on this topic has also struggled to overcome specific performance bottlenecks, which have limited use of this technology in real-time applications. Specifically, many stylized rendering techniques have difficulty operating on large-scale scenes, such as open-world terrain environments. In this paper, we describe various novel rendering techniques for mimicking hand-drawn art styles in a large-scale 3D environment, including modifications to existing methods for stroke rendering and hatch-line texturing. Our system focuses on providing various complex styles while maintaining real-time performance, to maximize user-interactability. Our results demonstrate improved performance over existing real-time methods, and offer a few unique style options for users, though the system still suffers from some visual inconsistencies.

<p>The problem of estimating an adequate level of detail for an object for a specific view is one of the important problems in computer 3d-graphics and is especially important in real-time applications. The well-known continuous level-of-detail technique, Real-time Optimally Adapting Meshes (ROAM), has been employed with success for almost 10 years but has at present, due to rapid development of graphics hardware, been found to be inadequate. Compared to many other level-of-detail techniques it cannot benefit from the higher triangle throughput available on graphics cards of today.</p><p>This thesis will describe the implementation of the new version of ROAM (informally known as ROAM 2.0) for the purpose of massive planetary data visualization. It will show how the problems of the old technique can be bridged to be able to adapt to newer graphics card while still benefiting from the advantages of ROAM. The resulting implementation that is presented here is specialized on spherical objects and handles both texture and geometry data of arbitrary large sizes in an efficient way.</p>

The problem of estimating an adequate level of detail for an object for a specific view is one of the important problems in computer 3d-graphics and is especially important in real-time applications. The well-known continuous level-of-detail technique, Real-time Optimally Adapting Meshes (ROAM), has been employed with success for almost 10 years but has at present, due to rapid development of graphics hardware, been found to be inadequate. Compared to many other level-of-detail techniques it cannot benefit from the higher triangle throughput available on graphics cards of today. This thesis will describe the implementation of the new version of ROAM (informally known as ROAM 2.0) for the purpose of massive planetary data visualization. It will show how the problems of the old technique can be bridged to be able to adapt to newer graphics card while still benefiting from the advantages of ROAM. The resulting implementation that is presented here is specialized on spherical objects and handles both texture and geometry data of arbitrary large sizes in an efficient way.