Globalno osvetljevanje z voksli

diplomsko delo

Andrej Ulčar (Author), Iztok Lebar Bajec (Mentor)

Abstract

V diplomski nalogi predstavimo pristop reševanja globalnega osvetljevanja 3D prostora, neodvisnega od pozicije kamere, s pomočjo vokslov. Opišemo pogoste težave pri globalnem osvetljevanju in predstavimo nekaj metod, ki ga rešujejo. Obrazložimo kako globalno osvetljevanje deluje ter predstavimo naš pristop naslavljanja težav povezanih z njim. Vokslom s sledenjem žarkov iz luči izračunamo direktno osvetljavo. V nadaljnjih odbojih voksli služijo kot luči za osvetljevanje ostalih vokslov. Glavna prednost našega algoritma je, da izračuna osvetlitev za celoten prostor neodvisno od položaja kamere in brez šuma. Ker so izračuni neodvisni od položaja kamere, nam to omogoči hiter ponoven izris po premiku kamere. Preverjanje rezultatov smo izvajali na treh scenah in s tremi drugimi algoritmi. V testnih primerih smo za prvi izračun osvetlitve prostora potrebovali nekaj ur, v najboljšem primeru 1 uro in pol. Po izračunu osvetlitve prostora smo pri premiku kamere za vsak ponoven izris potrebovali 20-25 sekund. V povprečju so rezultati našega algoritma odstopali le za 4,56% od referenčne slike ustvarjene z algoritmom Path tracing. Algoritem je časovno najbolj primeren za vizualizacijo statičnih scen iz mnogih zornih kotov, ker se nam čas prvega izračuna povrne že v nekaj slikah.

Keywords

voksel;računalniška grafika;3D grafika;grafika;direktno osvetljevanje;globalno osvetljevanje;računalništvo;računalništvo in informatika;visokošolski strokovni študij;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2020
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FRI - Faculty of Computer and Information Science
Publisher:	[A. Ulčar]
UDC:	004.92(043.2)
COBISS:	24097283
Views:	1643
Downloads:	214
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Voxel based global illumination
Secondary abstract:	In this diploma thesis we present an approach to global illumination of 3D space, regardless of camera position, with voxels. We present global illumination, explain a few methods that solve it and present common problems. We explain how it works and present our approach to the problem. With raytracing lights, we calculate direct illumination for voxels and then use voxels as lights to illuminate other voxels in subsequent bounces. The main advantage of our approach is that we calculate global illumination for the whole scene regardless of camera position and without noise. Data is camera independent, which enables fast rerendering after moving the camera. We conducted tests on three scenes and compared our algorithm against three others. In test cases, our approach required several hours to calculate initial illumination, in best case an hour and a half. After calculating initial illumination each subsequent camera render took only 20-25 seconds when moving the camera. Results of our algorithm deviated only 4.56% on average, from the reference image created with Path tracing algorithm. The algorithm is most suited for visualization of static scenes from multiple camera angles, because times spend on calculating scene illumination is gained back in just a few renders.
Secondary keywords:	voxel;computer graphics;3D graphics;direct illumination;global illumination;computer science;computer and information science;diploma;
Type (COBISS):	Bachelor thesis/paper
Study programme:	1000470
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za računalništvo in informatiko
Pages:	39 str.
ID:	11438276