Parallel photon-mapping rendering on a mesh-NoC-based MPSoC platform

• Three stages of photon-mapping rendering have been run in parallel.
• Load balancing, less memory usage and effective communication were considered.
• RPhC, RPC, L-KD and G-KD constructions were introduced as novel parallelism ideas.
• MPSoC with an adaptive wormhole routing mesh NoC was used to examine the methods.
• The proposed methods showed up to 44.3 times speed up compared to one core.

High demand 3-D scenes on embedded systems draw the developers’ attention to use the whole resources of current low-power processors and add dedicated hardware as a graphic accelerator unit to deal with real-time realistic scene rendering. Photon mapping, as one of the most powerful techniques to render highly realistic 3-D images by high amounts of floating-point operations, is very time-consuming. To use the advantages of multiprocessor systems to make 3-D scenes, parallel photon-mapping rendering on a homogeneous multiprocessor SoC (MPSoC) platform along with a mesh NoC by an adaptive wormhole routing method to communicate packets among cores is proposed in this paper. To make efficient use of the MPSoC platform to carry out photon-mapping rendering, many methods concerning the increase of load balancing, the efficient use of memory, and the decrease of communication cost to achieve a scalable application are explored in this paper. The resulting MPSoC platform is verified and evaluated by cycle-accurate simulations for different sizes of the mesh NoC. As expected, the proposed methods can obtain excellent load balancing and achieve a maximum of 44.3 times faster on an 8-by-8 MPSoC platform than on a single-core MPSoC platform.