faculty: "FNWI" and publication year: "2011"
| Author||Piotr Wachowicz|
|Title||Accelerating Photon Mapping with Photon Flipping and Invalidity Photons|
|Supervisor||Chris R. Jesshope|
|Faculty||Faculty of Science|
|Programme||FNWI MSc Grid Computing|
|Abstract||In this thesis I introduce two novel methods of accelerating photon mapping in interactive environments. They successfully tackle two of photon mapping's main problems. The photon flipping algorithm deals with the issue of having to retrace all direct and shadow photons whenever an object moves. The invalidity photons are a new proposed type of photons which helps to determine which areas of the image should undergo the process of regathering direct and shadow photons.
Photon flipping proved to increase the overall performance of direct/shadow photon scattering while also drastically reducing the number of required ray-triangle and ray-AABB collision tests. Making use of invalidity photons further increased the performance of my implementation by shortening the time needed for direct/shadow
I implemented the two aforementioned techniques using a novel method for storing all types of scattered photons. My method is based on spatial hashing. It differs from the previous work in storing photons using spatial hashing through the fact that it does not require the photons to be sorted after being scattered. I eliminated the need for sorting photons by dynamically assigning pre-allocated photon maps
to volumes of the scene which actually require it. The tradeoff here is an increased memory usage and the need to pre-estimate the maximum size of photon maps.
As an additional part of the research I performed an investigation into the usability of progressive photon mapping in interactive 3D environments. I also measured the performance increases in various situations gained from adaptively spawning multiple shadow rays during the generation of soft shadows. Additionally, I implemented
a simple and efficient method of performing 3D image composition of CUDA and OpenGL generated content.
Potential areas of application for my research into photon flipping and invalidity photons include almost any type of a real-time 3D rendering engine utilising photon mapping as the light transport model. The photon flipping algorithm and my photon storing approach can be successfully used with any type of image rendering algorithm. Invalidity photons are naturally suited for image order rendering algo-
rithms, such as ray tracing. My photon storing method proved to be best suited for photon types which tend to uniformly ll the scene's surfaces. After some modifications it can be, however, also used for other types of photons.|
|Document type|| scriptie master|
Use this url to link to this page: http://dare.uva.nl/en/scriptie/384474
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