S-Space College of Engineering/Engineering Practice School (공과대학/대학원) Dept. of Electrical and Computer Engineering (전기·정보공학부) Theses (Ph.D. / Sc.D._전기·정보공학부)
Slab-based Intermixing for Multi-Object Rendering of Heterogeneous Datasets
다중 이종 객체들의 렌더링을 위한 슬랩 기반 혼합 기법 연구
- 공과대학 전기·컴퓨터공학부
- Issue Date
- 서울대학교 대학원
- multi-object rendering; zSlab; z-thickness buffer; order-independent transparency; visibility interpolation; image-level intermixing
- 학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2016. 8. 신영길.
- The visualization of multiple 3D objects has been increasingly required for recent applications in many industrial, biomedical, and scientific fields. Due to the heterogeneity in data representation or data configuration, it is difficult to efficiently render multiple objects in high-level performance. In this dissertation, we propose a multi-object rendering method based on a novel intermixing model for high performance visualization of multiple volumetric and polygonal objects. To represent multiple layers of polygonal surfaces and volumetric fuzzy surfaces, we introduce zSlab model which is defined with visibility color, slab depth and finite thickness per pixel. zSlab is based on radiosity spreading out the viewing direction, which is a special ray-segment used for an intermixing unit.
As the proposed zSlab model is designed to treat multiple polygonal and volumetric geometries which may be unordered, we apply the order-independent-transparency (OIT) concept to the construction of zSlabs. With the proposed zSlab-based intermixing method, this enables image-level intermixing for a variety of object combinations
traditional polygon rendering for many transparent surfaces, hybrid rendering for polygon and volume, and multi-volume rendering.
First, we present how the zSlab is applied to volumetric fuzzy surface as well as infinitely thin surface of polygonal geometry with the proposed virtual zSlab concept. And, we introduce a novel z-thickness buffer that stores the zSlabs as an array, which is used for the rendering input and output. We introduce two versions of in-slab visibility interpolation methods and verify which model is well suit for the proposed intermixing algorithm. Finally, based on zSlab model and the in-slab visibility interpolation, we propose an efficient slab-based visibility intermixing algorithm so that the entire intermixing leads to a high performance rendering result (acceptable image result and fast rendering speed).
Experimental results demonstrate that the proposed method delivers more effective multi-object rendering in terms of taking advantages of the image-level intermixing especially for a rendering scene that includes at least one volumetric object, providing acceptable image quality compared to the image based on the conventional on-the-fly intermixing. And the proposed intermixing method is able to resolve traditional intermixing artifacts such as aliasing intersection and z-fighting plane occurred in intersecting or overlapping surface region. Moreover, our experimental results manifest a potential of the proposed method that it can deliver a substantial aid in scientific visualization of entire context including hidden (or, inside) structures in the multi-object scene.