Jaedon Lee

SGRT: a mobile GPU architecture for real-time ray tracing

Recently, with the increasing demand for photorealistic graphics and the rapid advances in desktop CPUs/GPUs, real-time ray tracing has attracted considerable attention. Unfortunately, ray tracing in the current mobile environment is very difficult because of inadequate computing power, memory bandwidth, and flexibility in mobile GPUs. In this paper, we present a novel mobile GPU architecture called SGRT (Samsung reconfigurable GPU based on Ray Tracing) in which a fast compact hardware accelerator and a flexible programmable shader are combined. SGRT has two key features: 1) an area-efficient parallel pipelined traversal unit; and 2) flexible and high-performance kernels for shading and ray generation. Simulation results show that SGRT is potentially a versatile graphics solution for future application processors as it provides a real-time ray tracing performance at full HD resolution that can compete with that of existing desktop GPU ray tracers. Our system is implemented on an FPGA platform, and mobile ray tracing is successfully demonstrated.

SGRT: a scalable mobile GPU architecture based on ray tracing

Recently, with the increasing demand for photorealistic graphics and the rapid advances in desktop CPUs/GPUs, real-time raytracing has attracted considerable attention. Unfortunately, raytracing in the current mobile environment is difficult because of inadequate computing power, memory bandwidth, and flexibility in mobile GPUs. In this work, we present a novel mobile GPU architecture called the SGRT (Samsung reconfigurable GPU based on RayTracing) by enhancing our previous works with the following features: 1) a fast compact hardware engine that accelerates a traversal and intersection operation, 2) a flexible reconfigurable processor that supports software ray generation and shading, and 3) a parallelization framework that achieves scalable performance. Unlike our previous work, the current architecture is designed for both static and dynamic scenes with a smaller area. Experimental results show that the SGRT can be a versatile graphics solution, as it supports compatible performance compared to desktop GPU raytracers. To the best of our knowledge, the SGRT is the first mobile GPU based on full Whitted raytracing.

Real-time ray tracing on coarse-grained reconfigurable processor

Ray tracing is a 3D rendering method for generating an image by simulating the path of light. It can generate high quality images, but it requires great computing power. Recent advances in ray tracing technology enable realtime ray tracing on modern desktop CPUs/GPUs. But in the current mobile environment, it is difficult because of inadequate computing power, memory bandwidth, and flexibility in mobile GPUs. In this paper, we present a mobile ray tracing system using Samsung Reconfigurable Processor (SRP). SRP architecture includes a tightly coupled very long instruction word (VLIW) engine and coarse-grained reconfigurable array (CGRA). The VLIW engine is designed for general-purpose computations, such as function invocation and branch selection, and the coarsegrained reconfigurable array is specialized for data-intensive part of the program and can be configured dynamically. We proposed iterative batch-based ray tracing algorithm for SRP, and optimized memory bandwidth with local memory and data cache. Our ray tracing system is implemented on a commercial FPGA-based prototyping system. The experimental results show that our system is suitable for the mobile ray tracing.

A novel mobile GPU architecture based on ray tracing

Recently, with the increasing demand for photorealistic graphics and the rapid advances in desktop CPUs/GPUs, real-time ray tracing has attracted considerable attention. Unfortunately, ray tracing in the current mobile environment is difficult because of inadequate computing power, memory bandwidth, and flexibility in mobile GPUs. In this paper, we present a novel mobile GPU architecture called the SGRT (Samsung reconfigurable GPU based on Ray Tracing) with the following features: 1) a fast compact hardware engine that accelerates a traversal and intersection operation, 2) a flexible reconfigurable processor that supports software ray generation and shading, and 3) a parallelization framework that achieves scalable performance. Experimental results show that the SGRT can be a versatile graphics solution, as it supports compatible performance compared to desktop GPU ray tracers.

Energy efficient data transmission for ray tracing on mobile computing platform

In this paper, we focus the impact of a memory bandwidth limitation by analyzing the bandwidth consumption for ray tracing system and present an energy efficient data transmission method between processor and ray tracing hardware engine. For evaluation of our approach, we have implemented a prototype of ray tracing architecture using our approach on FPGA platform. According to our experiment result, our approach shows a 48% reduction of system memory bandwidth on average.

Full-stream architecture for ray tracing with efficient data transmission

In this paper, we focus on the impact of a memory bandwidth limitation by analyzing the bandwidth consumption for a ray tracing system and present an energy efficient data transmission method using a dedicated interface between the processor and ray tracing hardware engine. To achieve real-time ray tracing, we propose a full-stream architecture through the use of this dedicated interface. For an evaluation of our approach, we implemented a prototype ray tracing architecture using our approach on an FPGA platform. Our experimental results, indicate that our approach shows an average reduction in system memory bandwidth of 48% and an average performance improvement of 50%.

Selective multi-sample anti-aliasing for mobile vector graphics

Vector graphics is a key technology for drawing 2D graphics images on the mobile devices. As screen resolution increases and multi-touch interface is widely used in mobile devices, the efficient solution for vector graphics becomes more important. For future mobile environments, we should process vector graphics with high performance and low power. In this paper, we have proposed the efficient anti-aliasing algorithm for mobile vector graphics. We can have greatly reduced sample counts by selective multi-sampling, which uses multi-sampling only for the pixels which meet the contour of the image. We can find the multi-sampling pixel by simple pixel-primitive intersection test. To reduce the cost of intersection test, we have proposed the pixel block algorithm which processes adjacent pixels together. For more optimization, we use hierarchical sampling. Our optimized S-MSAA (Selective Multi-Sample Anti-Aliasing) is 29.4 times faster than the original 16× MSAA.

Tile binning and rendering for resolution independent graphics

In this paper, we present an efficient resolution independent path rendering algorithm. To do so, we propose tile binning and rendering algorithm for resolution independent path rendering which is suitable to use on mobile device. Experimental comparisons show that our scheme reduces not only most of memory I/O overhead but also 50% of computation overhead. As the result, most of mobile phones can enjoy scalable high performance path rendering with our scheme.

A system framework and API for run-time adaptable parallel software

A system framework supporting run-time dynamic adaptation of parallel applications is proposed. The framework consists of a run-time manager and an API. The run-time manager profiles applications and guides adaption of applications at run-time for optimization and adaptation to the changes of environment such as the number of cores to use. With the proposed API, a range of different parallelization can be provided inside of an application, and the run-time manager chooses an appropriate parallelization at run-time. With the aid of the proposed run-time manager, a program can adapt/morph itself to dynamic changes in the system resources and/or performance requirements at run-time. The proposed adaptive run-time manager monitors and guides the applications to make the system adaptable at run-time.