Condenser-Based Instant Reflectometry
نویسندگان
چکیده
We present a technique for rapid capture of high quality bidirectional reflection distribution functions(BRDFs) of surface points. Our method represents the BRDF at each point by a generalized microfacet model with tabulated normal distribution function (NDF) and assumes that the BRDF is symmetrical. A compact and light-weight reflectometry apparatus is developed for capturing reflectance data from each surface point within one second. The device consists of a pair of condenser lenses, a video camera, and six LED light sources. During capture, the reflected rays from a surface point lit by a LED lighting are refracted by a condenser lenses and efficiently collected by the camera CCD. Taking advantage of BRDF symmetry, our reflectometry apparatus provides an efficient optical design to improve the measurement quality. We also propose a model fitting algorithm for reconstructing the generalized microfacet model from the sparse BRDF slices captured from a material surface point. Our new algorithm addresses the measurement errors and generates more accurate results than previous work. Our technique provides a practical and efficient solution for BRDF acquisition, especially for materials with anisotropic reflectance. We test the accuracy of our approach by comparing our results with ground truth. We demonstrate the efficiency of our reflectometry by measuring materials with different degrees of specularity, values of Fresnel factor, and angular variation.
منابع مشابه
On the Excitation of Tissue by Means of Condenser Discharges
Equations are derived for the capacity-voltage relations for stimulation of tissue by condenser discharges, using the hypothesis that the local excitatory process p grows under the influence of an applied potential V according to the equation, See PDF for Equation where K and k are constants. It is further assumed that the local excitatory process becomes adequate when it attains a value h +/- ...
متن کاملDesign Of High Energy-Efficiency Air Conditioner With Asymmetric Fin Condenser Tube
This paper presents the detailed design and analysis of an asymmetric fin tube condenser. And the heat transfer performance of the asymmetric fin tube condenser is simulated with the fluent software. Based on the simulation results, an optimal model of the asymmetric-finned tube condenser is designed. The actual model is experimentally studied on air conditioners and contrasted with the symmetr...
متن کاملاثرات نرمی پتانسیل بین سطوح بر روی بازتابندگی، فاز و قطبش نوترون‌های بازتابیده از لایه‌های مغناطیسی در بازتاب سنجی نوترونی
In the past decades, neutron reflectometry have flourished as an applicable method to the study of thin films. As an example, the type and thickness of an unknown thin film which is mounted on top of a magnetic substratum could be determined by measuring the intensity and polarization of the reflected neutrons from the sample. Neutron reflectometry is based on solving the one dimentional schröd...
متن کاملSignal to Noise Ratio (SNR) Enhancement Comparison of Impulse-, Coding- and Novel Linear-Frequency-Chirp-Based Optical Time Domain Reflectometry (OTDR) for Passive Optical Network (PON) Monitoring Based on Unique Combinations of Wavelength Selective Mirrors
We compare optical time domain reflectometry (OTDR) techniques based on conventional single impulse, coding and linear frequency chirps concerning their signal to noise ratio (SNR) enhancements by measurements in a passive optical network (PON) with a maximum one-way attenuation of 36.6 dB. A total of six subscribers, each represented by a unique mirror pair with narrow reflection bandwidths, a...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Comput. Graph. Forum
دوره 29 شماره
صفحات -
تاریخ انتشار 2010