Ray-Traced Reflections in Real-Time Using Heuristic Based Hybrid Rendering

Author(s):  
Paulo Andrade ◽  
Thales Sabino ◽  
Esteban Clua ◽  
Paulo Pagliosa
Keyword(s):  
2014 ◽  
Vol 31 (10) ◽  
pp. 1395-1403 ◽  
Author(s):  
Per Ganestam ◽  
Michael Doggett
Keyword(s):  

1997 ◽  
Vol 36 (01) ◽  
pp. 1-10 ◽  
Author(s):  
M. Haubner ◽  
A. Lösch ◽  
F. Eckstein ◽  
M. D. Seemann ◽  
W. van Eimeren ◽  
...  

Abstract:The most important rendering methods applied in medical imaging are surface and volume rendering techniques. Each approach has its own advantages and limitations: Fast surface-oriented methods are able to support real-time interaction and manipulation. The underlying representation, however, is dependent on intensive image processing to extract the object surfaces. In contrast, volume visualization is not necessarily based on extensive image processing and interpretation. No data reduction to geometric primitives, such as polygons, is required. Therefore, the process of volume rendering is currently not operating in real time. In order to provide the radiological diagnosis with additional information as well as to enable simulation and preoperative treatment planning we developed a new hybrid rendering method which combines the advantages of surface and volume presentation, and minimizes the limitations of these approaches. We developed a common data representation method for both techniques. A preprocessing module enables the construction of a data volume by interpolation as well as the calculation of object surfaces by semiautomatic image interpretation and surface construction. The hybrid rendering system is based on transparency and texture mapping features. It is embedded in a user-friendly open system which enables the support of new application fields such as virtual reality and stereolithography. The efficiency of our new method is described for 3-D subtraction angiography and the visualization of morpho-functional relationships.


Open Physics ◽  
2019 ◽  
Vol 17 (1) ◽  
pp. 527-544 ◽  
Author(s):  
Patryk Walewski ◽  
Tomasz Gałaj ◽  
Dominik Szajerman

Abstract Nowadays, rasterization is the most common method used to achieve real-time semi-photorealistic effects in games or interactive applications. Some of those effects are not easily achievable, thus require more complicated methods and are difficult to obtain. The appearance of the presented worlds depends to a large extent on the approximation to the physical basis of light behaviour in them. The best effects in this regard are global illumination algorithms. Each of them including ray tracing give the most plausible effects, but at cost of higher computational complexity. Today’s hardware allows usage of ray tracing methods in-real time on Graphics Processing Units (GPU) thanks to its parallel nature. However, using ray tracing as a single rendering method may still result in poor performance, especially when used to create many image effects in complex environments. In this paper we present a hybrid approach for real-time rendering using both rasterization and ray tracing using heuristic, which determines whether to render secondary effects such as shadows, reflections and refractions for individual objects considering their relevancy and cost of rendering those effects for these objects in particular case.


2019 ◽  
pp. 437-473 ◽  
Author(s):  
Colin Barré-Brisebois ◽  
Henrik Halén ◽  
Graham Wihlidal ◽  
Andrew Lauritzen ◽  
Jasper Bekkers ◽  
...  

1979 ◽  
Vol 44 ◽  
pp. 41-47
Author(s):  
Donald A. Landman

This paper describes some recent results of our quiescent prominence spectrometry program at the Mees Solar Observatory on Haleakala. The observations were made with the 25 cm coronagraph/coudé spectrograph system using a silicon vidicon detector. This detector consists of 500 contiguous channels covering approximately 6 or 80 Å, depending on the grating used. The instrument is interfaced to the Observatory’s PDP 11/45 computer system, and has the important advantages of wide spectral response, linearity and signal-averaging with real-time display. Its principal drawback is the relatively small target size. For the present work, the aperture was about 3″ × 5″. Absolute intensity calibrations were made by measuring quiet regions near sun center.


Author(s):  
Alan S. Rudolph ◽  
Ronald R. Price

We have employed cryoelectron microscopy to visualize events that occur during the freeze-drying of artificial membranes by employing real time video capture techniques. Artificial membranes or liposomes which are spherical structures within internal aqueous space are stabilized by water which provides the driving force for spontaneous self-assembly of these structures. Previous assays of damage to these structures which are induced by freeze drying reveal that the two principal deleterious events that occur are 1) fusion of liposomes and 2) leakage of contents trapped within the liposome [1]. In the past the only way to access these events was to examine the liposomes following the dehydration event. This technique allows the event to be monitored in real time as the liposomes destabilize and as water is sublimed at cryo temperatures in the vacuum of the microscope. The method by which liposomes are compromised by freeze-drying are largely unknown. This technique has shown that cryo-protectants such as glycerol and carbohydrates are able to maintain liposomal structure throughout the drying process.


Author(s):  
R.P. Goehner ◽  
W.T. Hatfield ◽  
Prakash Rao

Computer programs are now available in various laboratories for the indexing and simulation of transmission electron diffraction patterns. Although these programs address themselves to the solution of various aspects of the indexing and simulation process, the ultimate goal is to perform real time diffraction pattern analysis directly off of the imaging screen of the transmission electron microscope. The program to be described in this paper represents one step prior to real time analysis. It involves the combination of two programs, described in an earlier paper(l), into a single program for use on an interactive basis with a minicomputer. In our case, the minicomputer is an INTERDATA 70 equipped with a Tektronix 4010-1 graphical display terminal and hard copy unit.A simplified flow diagram of the combined program, written in Fortran IV, is shown in Figure 1. It consists of two programs INDEX and TEDP which index and simulate electron diffraction patterns respectively. The user has the option of choosing either the indexing or simulating aspects of the combined program.


Author(s):  
R. Rajesh ◽  
R. Droopad ◽  
C. H. Kuo ◽  
R. W. Carpenter ◽  
G. N. Maracas

Knowledge of material pseudodielectric functions at MBE growth temperatures is essential for achieving in-situ, real time growth control. This allows us to accurately monitor and control thicknesses of the layers during growth. Undesired effusion cell temperature fluctuations during growth can thus be compensated for in real-time by spectroscopic ellipsometry. The accuracy in determining pseudodielectric functions is increased if one does not require applying a structure model to correct for the presence of an unknown surface layer such as a native oxide. Performing these measurements in an MBE reactor on as-grown material gives us this advantage. Thus, a simple three phase model (vacuum/thin film/substrate) can be used to obtain thin film data without uncertainties arising from a surface oxide layer of unknown composition and temperature dependence.In this study, we obtain the pseudodielectric functions of MBE-grown AlAs from growth temperature (650°C) to room temperature (30°C). The profile of the wavelength-dependent function from the ellipsometry data indicated a rough surface after growth of 0.5 μm of AlAs at a substrate temperature of 600°C, which is typical for MBE-growth of GaAs.


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