47,586 research outputs found
GENERATION OF FORESTS ON TERRAIN WITH DYNAMIC LIGHTING AND SHADOWING
The purpose of this research project is to exhibit an efficient method of creating dynamic lighting and shadowing for the generation of forests on terrain. In this research project, I use textures which contain images of trees from a bird’s eye view in order to create a high scale forest. Furthermore, by manipulating the transparency and color of the textures according to the algorithmic calculations of light and shadow on terrain, I provide the functionality of dynamic lighting and shadowing. Finally, by analyzing the OpenGL pipeline, I design my code in order to allow efficient rendering of the forest
Real-time voxel rendering algorithm based on screen space billboard voxel buffer with sparse lookup textures
In this paper, we present a novel approach to efficient real-time rendering of numerous high-resolution voxelized
objects. We present a voxel rendering algorithm based on triangle rasterization pipeline with screen space rendering
computational complexity. In order to limit the number of vertex shader invocations, voxel filtering algorithm
with fixed size voxel data buffer was developed. Voxelized objects are represented by sparse voxel octree (SVO)
structure. Using sparse texture available in modern graphics APIs, we create a 3D lookup table for voxel ids.
Voxel filtering algorithm is based on 3D sparse texture ray marching approach. Screen Space Billboard Voxel
Buffer is filled by voxels from visible voxels point cloud. Thanks to using 3D sparse textures, we are able to store
high-resolution objects in VRAM memory. Moreover, sparse texture mipmaps can be used to control object level
of detail (LOD). The geometry of a voxelized object is represented by a collection of points extracted from object
SVO. Each point is defined by position, normal vector and texture coordinates. We also show how to take advantage
of programmable geometry shaders in order to store voxel objects with extremely low memory requirements and to
perform real-time visualization. Moreover, geometry shaders are used to generate billboard quads from the point
cloud and to perform fast face culling. As a result, we obtained comparable or even better performance results
in comparison to SVO ray tracing approach. The number of rendered voxels is limited to defined Screen Space
Billboard Voxel Buffer resolution. Last but not least, thanks to graphics card adapter support, developed algorithm
can be easily integrated with any graphics engine using triangle rasterization pipeline
Interactive Vegetation Rendering with Slicing and Blending
Detailed and interactive 3D rendering of vegetation is one of the challenges of traditional polygon-oriented computer graphics, due to large geometric complexity even of simple plants. In this paper we introduce a simplified image-based rendering approach based solely on alpha-blended textured polygons. The simplification is based on the limitations of human perception of complex geometry. Our approach renders dozens of detailed trees in real-time with off-the-shelf hardware, while providing significantly improved image quality over existing real-time techniques. The method is based on using ordinary mesh-based rendering for the solid parts of a tree, its trunk and limbs. The sparse parts of a tree, its twigs and leaves, are instead represented with a set of slices, an image-based representation. A slice is a planar layer, represented with an ordinary alpha or color-keyed texture; a set of parallel slices is a slicing. Rendering from an arbitrary viewpoint in a 360 degree circle around the center of a tree is achieved by blending between the nearest two slicings. In our implementation, only 6 slicings with 5 slices each are sufficient to visualize a tree for a moving or stationary observer with the perceptually similar quality as the original model
Fractal descriptors based on the probability dimension: a texture analysis and classification approach
In this work, we propose a novel technique for obtaining descriptors of
gray-level texture images. The descriptors are provided by applying a
multiscale transform to the fractal dimension of the image estimated through
the probability (Voss) method. The effectiveness of the descriptors is verified
in a classification task using benchmark over texture datasets. The results
obtained demonstrate the efficiency of the proposed method as a tool for the
description and discrimination of texture images.Comment: 7 pages, 6 figures. arXiv admin note: text overlap with
arXiv:1205.282
Evaluation of optimisation techniques for multiscopic rendering
A thesis submitted to the University of Bedfordshire in fulfilment of the requirements for the degree of Master of Science by ResearchThis project evaluates different performance optimisation techniques applied to stereoscopic and multiscopic rendering for interactive applications. The artefact
features a robust plug-in package for the Unity game engine. The thesis provides background information for the performance optimisations, outlines all the findings, evaluates the optimisations and provides suggestions for future work.
Scrum development methodology is used to develop the artefact and quantitative research methodology is used to evaluate the findings by measuring performance.
This project concludes that the use of each performance optimisation has specific use case scenarios in which performance benefits. Foveated rendering provides
greatest performance increase for both stereoscopic and multiscopic rendering but is also more computationally intensive as it requires an eye tracking solution.
Dynamic resolution is very beneficial when overall frame rate smoothness is needed and frame drops are present. Depth optimisation is beneficial for vast open environments but can lead to decreased performance if used inappropriately
SHOWMe: Benchmarking Object-agnostic Hand-Object 3D Reconstruction
Recent hand-object interaction datasets show limited real object variability
and rely on fitting the MANO parametric model to obtain groundtruth hand
shapes. To go beyond these limitations and spur further research, we introduce
the SHOWMe dataset which consists of 96 videos, annotated with real and
detailed hand-object 3D textured meshes. Following recent work, we consider a
rigid hand-object scenario, in which the pose of the hand with respect to the
object remains constant during the whole video sequence. This assumption allows
us to register sub-millimetre-precise groundtruth 3D scans to the image
sequences in SHOWMe. Although simpler, this hypothesis makes sense in terms of
applications where the required accuracy and level of detail is important eg.,
object hand-over in human-robot collaboration, object scanning, or manipulation
and contact point analysis. Importantly, the rigidity of the hand-object
systems allows to tackle video-based 3D reconstruction of unknown hand-held
objects using a 2-stage pipeline consisting of a rigid registration step
followed by a multi-view reconstruction (MVR) part. We carefully evaluate a set
of non-trivial baselines for these two stages and show that it is possible to
achieve promising object-agnostic 3D hand-object reconstructions employing an
SfM toolbox or a hand pose estimator to recover the rigid transforms and
off-the-shelf MVR algorithms. However, these methods remain sensitive to the
initial camera pose estimates which might be imprecise due to lack of textures
on the objects or heavy occlusions of the hands, leaving room for improvements
in the reconstruction. Code and dataset are available at
https://europe.naverlabs.com/research/showmeComment: Paper and Appendix, Accepted in ACVR workshop at ICCV conferenc
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