• Title/Summary/Keyword: Ray-Tracing Technique

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Implementation and Simulation of 2D Ray-tracing Technique in Multiple-wall Indoor Environment (다중 벽면 구조의 실내 환경에서 2차원 광선추적법 구현 및 시뮬레이션)

  • Jeong, Seung-Heui;Kang, Chul-Gyu;Oh, Chang-Heon
    • Journal of Digital Contents Society
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    • v.8 no.4
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    • pp.459-465
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    • 2007
  • In this paper, we implemented a ray-tracing simulator with a ray-launching technique and generated the propagation path of each ray in a multiple-wall indoor environment. In this simulator, we adopted two dimension ray-tracing techniques considering the reflection and penetration were dominant propagation factor in the indoor channel. From the result, we verified that this ray-tracing simulator shows the similar path pattern and delay distribution with the experiment results of the previous research. Especially, impulse responses of the ray were corresponding to reference result in non-line of sight of multiple-wall indoor environment. Furthermore, we confirmed that channel profiles having respectively different departure angle 1 degree to 7 degree were similar between them.

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Adaptive Foveated Ray Tracing Based on Time-Constrained Rendering for Head-Mounted Display (헤드 마운티드 디스플레이를 위한 시간 제약 렌더링을 이용한 적응적 포비티드 광선 추적법)

  • Kim, Youngwook;Ihm, Insung
    • Journal of the Korea Computer Graphics Society
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    • v.28 no.3
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    • pp.113-123
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    • 2022
  • Ray tracing-based rendering creates by far more realistic images than the traditional rasterization-based rendering. However, it is still burdensome when implemented for a Head-Mounted Display (HMD) system that demands a wide field of view and a high display refresh rate. Furthermore, for presenting high-quality images on the HMD screen, a sufficient number of ray sampling should be carried out per pixel to alleviate visually annoying spatial and temporal aliases. In this paper, we extend the recent selective foveated ray tracing technique by Kim et al. [1], and propose an improved real-time rendering technique that realizes the rendering effect of the classic Whitted-style ray tracing on the HMD system. In particular, by combining the ray tracing hardware-based acceleration technique and time-constrained rendering scheme, we show that fast HMD ray tracing is possible that is well suited to human visual systems.

Implementation and Evaluation of 2D Ray-Tracing Technique for Indoor Propagation Characteristics Modeling (실내 전파특성 모델링을 위한 2차원 광선추적법 구현 및 평가)

  • Jeong, Seung-Heui;Kang, Chul-Gyu;Oh, Chang-Heon
    • Journal of Advanced Navigation Technology
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    • v.11 no.4
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    • pp.454-460
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    • 2007
  • In this paper, we implemented a ray-tracing simulator with a ray-launching technique and generated the propagation path of each ray in an multiple-wall indoor environment. In this simulator, we adopted two dimension ray-tracing techniques considering the reflection and penetration were dominant propagation factor in the indoor channel. From the result, we verified that this ray-tracing simulator shows the similar pattern and delay distribution with the experiment results of the previous research.

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Interior Noise Analysis for Rolling Stocks by Ray tracing Method (Ray Tracing 기법을 이용한 철도차량 실태소음 해석)

  • 이용관;정승원
    • Proceedings of the KSR Conference
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    • 1998.11a
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    • pp.388-397
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    • 1998
  • This paper gives the way of analyzing internal noise of rolling stocks which is urgently required by civilians. Triangular beam method among ray tracing techniques is utilized to compute noise distribution of rolling stocks. Noise source and transmisstion loss of several sections from experimental work are included in this calculation. Ray tracing technique is found useful to compute big structures like rolling stocks.

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Analysis of Sun Tracking Error Caused by the Heliostat Driving Axis Geometrical Error Utilizing the Solar Ray Tracing Technique (태양광선 제적추적기법을 이용한 Heliostat 구동축 기구오차에서 기인하는 태양추적오차의 분석)

  • Park, Young-Chil
    • Journal of the Korean Solar Energy Society
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    • v.29 no.2
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    • pp.39-46
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    • 2009
  • Heliostat, as a mirror system tracking the sun's movement, is the most important subsystem determining the efficiency of solar thermal power plant. Thus the accurate sun tracking performance under the various hazardous operating condition, is required. This study presents a methodology of development of the solar ray tracing technique and the application of it in the analysis of sun tracking error due to the heliostat geometrical errors. The geometrical errors considered here are the azimuth axis tilting error and the elevation axis tilting error. We first analyze the geometry of solar ray reflected from the heliostat. Then the point on the receiver, where the solar ray reflected from the heliostat is landed, is computed and compared with the original intended point, which represents the sun tracking error. The result obtained shows that the effect of geometrical error on the sun tracking performance is varying with time(season) and the heliostat location. It also shows that the heliostat located near the solar tower has larger sun tracking error than that of the heliostat located farther.

Prediction of Electromagnetic Wave Propagation in Space Environments Based on Geometrical Optics

  • Kim, Changseong;Park, Yong Bae
    • Journal of electromagnetic engineering and science
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    • v.17 no.3
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    • pp.165-167
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    • 2017
  • We predict the electromagnetic wave propagation in space environments using geometrical optics. The effective indices of the troposphere, stratosphere, and ionosphere are computed, and the reflection, refraction, and attenuation of electromagnetic waves in space environments are calculated based on the ray tracing technique and geometrical optics. The influence of the refractive index and loss of atmosphere and the incident angle of the antenna on electromagnetic wave propagation is discussed.

Analysis of the indoor radio signal propagation characteristics by ray-tracing technique (Ray-Tracing을 이용한 구내 전파 전파특성 해석)

  • Ryu, Hwang
    • The Journal of Natural Sciences
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    • v.8 no.2
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    • pp.101-109
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    • 1996
  • In this paper, using the derived formula based on field theory both geometrical optics and diffraction theory, several features of same buildings of Bertoni's construction that influence the propagation of signals between antennas located on the same floor have been investigated theoretically and compared with previously studied results.

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The Ray Tracing Modeling Using the Modified Image Method in Microcellular Environment (개선된 영상기법을 이용한 마이크로셀 환경에서의 전파경로 추적 모델링)

  • 송기홍;함영권;이혁재
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.7 no.1
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    • pp.15-25
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    • 1996
  • This paper proposes the modified image method scheme to search the reflected points and the method to calculate the number of rays. These methods are applied to the ray tracing technique for received power and delay profile prediction in microcelular environment. With ray tracing model using these methods, we show the simulated results for various environmental structures. To demonstrate the validity of this approach, these simulated results are compared and analysed with measured results in apartment towns along the street. In addition we proposed the optimum number of multipath rays with the results in microcellular environment.

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HST exterior noise : prediction and reduction scheme by using ray tracing technique (고속철도 차량의 외부소음 예측 및 저감 연구 : 광음향기법 응용)

  • Hong, Yun-H.;Kim, Sung-T.;Kim, Jung-Soo
    • Proceedings of the KSR Conference
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    • 2009.05b
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    • pp.209-214
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    • 2009
  • In this research, an external noise distribution of a HST has been analyzed by using a ray tracing techniques. An aero-dynamic noise generated from a bogie has been considered as a major noise source. Then a distribution of the noise on the outside of the vehicle is calculated using a ray noise technique. The models simulated are two different acoustic fields: an open field and a tunnel. In order to evaluate the noise effects, an exterior structure has been modified by using a different length of skirts. Various application schemes of reducing an environmental noise level will be expected for a HST based on this research.

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A study on Algorithm Automatically Generating Ray Codes for Ray-tracing (파선코드 자동생성 알고리즘에 관한 연구)

  • Lee, Hee-Il;Cho, Chang-Soo
    • Geophysics and Geophysical Exploration
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    • v.11 no.4
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    • pp.361-367
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    • 2008
  • When constructing a synthetic seismogram in the earthquake study or in seismic data interpretation by using a ray-tracing technique, the most troublesome and error-prone task is to define a suite of ray codes for the corresponding rays to trace in advance. An infinite number of rays exist for any arbitrarily located source and receiver in a medium. Missing certain important rays or an inappropriate selection of ray codes in tracing rays may result in wrong interpretation of the earthquake record or seismogram. Automatic ray code generation could be able to eliminate those problems. In this study we have developed an efficient algorithm with which one can generate systematically all the ray codes for the source(s) and receiver(s) arbitrarily located in a model. The result of this work could be used not only in analysing multiples in seismic data processing and interpretation, but also in coda wave study, study on the amplification effects in a basin and phase identification of the waves multiply reflected/refracted in earthquake study.