43 research outputs found
Detecting Aliasing Artifacts in Image Sequences Using Deep Neural Networks
No full textIn this short paper we present a machine learning approach to detect visual artifacts in rendered image sequences. Specifically, we train a deep neural network using example aliased and antialiased image sequences exported from a real-time renderer. The trained network learns to identify and locate aliasing artifacts in an input sequence, without comparing it against a ground truth. Thus, it is useful as a fully automated tool for evaluating image quality. We demonstrate the effectiveness of our approach in detecting aliasing in several rendered sequences. The trained network correctly predicts aliasing in 64×64×4 animated sequences with more than 90% accuracy for images it hasn't seen before. The output of our network is a single scalar between 0 and 1, which is usable as a quality metric for aliasing. It follows the same trend as (1-SSIM) for images with increasing sample counts.Eurographics/ ACM SIGGRAPH Symposium on High Performance GraphicsAnti Aliasin
Deferred Adaptive Compute Shading
No full textA primary advantage of deferred shading is eliminating wasted shading operations due to overdraw. We present a new algorithm that we call Deferred Adaptive Compute Shading, for providing further reduction in shading computations. Our method hierarchically shades the image while reducing the number of required shading operations to below one shading computation per pixel on average. We determine whether to shade a pixel or approximate it using previously shaded pixels around it, based on an estimate of the image variance at the pixel location. The algorithm is designed to dynamically reconfigure itself to achieve optimal warp coherence and measurable performance gain. We extensively evaluate our algorithm, demonstrating that it produces high-quality results and is robust and highly scalable while providing significant performance improvements in complex scenes.Eurographics/ ACM SIGGRAPH Symposium on High Performance GraphicsAnti Aliasin
Brook GLES Pi: Democratising Accelerator Programming
No full textNowadays computing is heavily-based on accelerators, however, the cost of the hardware equipment prevents equal access to heterogeneous programming. In this work we present Brook GLES Pi, a port of the accelerator programming language Brook. Our solution, primarily focused on the educational platform Raspberry Pi, allows to teach, experiment and take advantage of heterogeneous programming on any low-cost embedded device featuring an OpenGL ES 2 GPU, democratising access to accelerator programming.Eurographics/ ACM SIGGRAPH Symposium on High Performance GraphicsRay Traversal, Transparency, and GPU Computin
Correlation-Aware Semi-Analytic Visibility for Antialiased Rendering
No full textGeometric aliasing is a persistent challenge for real-time rendering. Hardware multisampling remains limited to 8×, analytic coverage fails to capture correlated visibility samples, and spatial and temporal postfiltering primarily target edges of superpixel primitives. We describe a novel semi-analytic representation of coverage designed to make progress on geometric antialiasing for subpixel primitives and pixels containing many edges while handling correlated subpixel coverage. Although not yet fast enough to deploy, it crosses three critical thresholds: image quality comparable to 256× MSAA, faster than 64× MSAA, and constant space per pixel.Eurographics/ ACM SIGGRAPH Symposium on High Performance GraphicsAnti Aliasin
Moment Transparency
No full textWe introduce moment transparency, a new solution to real-time order-independent transparency. It expands upon existing approximate transmittance function techniques by using moments to capture and reconstruct the transmittance function. Because the momentbased transmittance function can be processed analytically using standard hardware blend operations, it is efficient and overcomes limitations of previous techniques.Eurographics/ ACM SIGGRAPH Symposium on High Performance GraphicsRay Traversal, Transparency, and GPU Computin
Adaptive Temporal Antialiasing
No full textWe introduce a pragmatic algorithm for real-time adaptive supersampling in games. It extends temporal antialiasing of rasterized images with adaptive ray tracing, and conforms to the constraints of a commercial game engine and today's GPU ray tracing APIs. The algorithm removes blurring and ghosting artifacts associated with standard temporal antialiasing and achieves quality approaching 8× supersampling of geometry, shading, and materials while staying within the 33ms frame budget required of most games.Eurographics/ ACM SIGGRAPH Symposium on High Performance GraphicsAnti Aliasin
Real-time Reyes-style adaptive surface subdivision
No full textWe present a GPU based implementation of Reyes-style adaptive surface subdivision, known in Reyes terminology as the Bound/Split and Dice stages. The performance of this task is important for the Reyes pipeline to map efficiently to graphics hardware, but its recursive nature and irregular and unbounded memory requirements present a challenge to an efficient implementation. Our solution begins by characterizing Reyes subdivision as a work queue with irregular computation, targeted to a massively parallel GPU. We propose efficient solutions to these general problems by casting our solution in terms of the fundamental primitives of prefix-sum and reduction, often encountered in parallel and GPGPU environments. Our results indicate that real-time Reyes subdivision can indeed be obtained on today's GPUs. We are able to subdivide a complex model to subpixel accuracy within 15 ms. Our measured performance is several times better than that of Pixar's RenderMan. Our implementation scales well with the input size and depth of subdivision. We also address concerns of memory size and bandwidth, and analyze the feasibility of conventional ideas on screen-space buckets
Parallel view-dependent tessellation of Catmull-Clark subdivision surfaces
No full textWe present a strategy for performing view-adaptive, crack-free tessellation of Catmull-Clark subdivision surfaces entirely on programmable graphics hardware. Our scheme extends the concept of breadth-first subdivision, which up to this point has only been applied to parametric patches. While mesh representations designed for a CPU often involve pointer-based structures and irregular per-element storage, neither of these is well-suited to GPU execution. To solve this problem, we use a simple yet effective data structure for representing a subdivision mesh, and design a careful algorithm to update the mesh in a completely parallel manner. We demonstrate that in spite of the complexities of the subdivision procedure, real-time tessellation to pixel-sized primitives can be done. Our implementation does not rely on any approximation of the limit surface, and avoids both subdivision cracks and T-junctions in the subdivided mesh. Using the approach in this paper, we are able to perform real-time subdivision for several static as well as animated models. Rendering performance is scalable for increasingly complex models
