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LARK MULTI-SPECTRAL LIGHTING SIMULATION TOOL: CALCULATION OF CIRCADIAN LIGHT

A growing body of research has shown that human ocular system functions not only to facilitate vision but to reset the circadian clock to synchronize it with the 24 hour daily cycle and/or with the local time. Lighting professionals increasingly appreciate the influence of light on human health and wellbeing. A holistic approach to design necessitates consideration for both visual and non-visual aspects of lighting. There are established methods for analyzing the luminous environment for photopic responses, but there is a need for a workflow to study and analyze non-visual impact of light in built environments. This research addresses this need. The objective of this research is to develop a multispectral lighting simulation tool that can be used to calculate both photopic and melanopic lighting values (v.0 - v.1.0) and neuropic lighting values (v.3.0). Instead of utilizing the traditional 3 channel simulation, multi channel simulation allows the user to divide the spectra in any number of channels.

SOFTWARE:

Lark Multi-Spectral Lighting tool, is developed in Grasshoper/Rhino environment. The simulation engine is Radiance; and Lark is provided as an open source and freely available tool. The objective is to make circadian lighting analysis more accessible to architects, lighting designers, researchers, and other interested parties. Lark allows for simulations both in 3 and 9 channels. Along with photopic luminance and illuminance values, Equivalent melanopic illuminance (EML), and Equivalent Neuropic illuminance (ENL) and -luminance (EM.cd/m2) values are computed. Lark Spectral Lighting Tool reaches new milestones: Lark Version 3.0 is developed as a collaboration between Univeristy of Washington (Mehlika Inanici, Ph.D., Bo Jung, and Zining Cheng) and ZGF Architects. It is funded by Appled Research Consurtium and ZGF Architects based on v.1.0 and 2.0. It can be downloaded from Food4Rhino. Github link, Youtube link (for tutorials). Blog on v.3.0. Lark version 2.0 is developed by Clotilde Pierson, Ph.D. (EPFL, Oregon State University) and Myrta Gkaintatzi-Masouti, M.Sc. (Eindhoven University of Technology ) based on Lark v.1.0. After 7 years of beta version, Lark 1.0 is released in 2022 as a collaboration between Mehlika Inanici (University of Washington) and ZGF Architects (with Marty Brennan). Lark was originallt developed as a collaboration between Mehlika Inanici (University of Washington) and ZGF Architects (with Marty Brennan and Ed Clark) and beta version of Lark is releasaed in 2015. Relevant blog v1.0.

PUBLICATIONS:

• Jung B, Cheng Z, Brennan M, Inanici M. "Multispectral Lighting Simulation Approaches for Predicting Opsin-driven Metrics and their Application in a Neonatal Intensive Care Unit," IBPSA 2023 Conference, Shanghai, China, September 4-6, 2023.

• Inanici M, Brennan M, and Clark E. "Spectral Lighting Simulations: Computing Circadian Light," International Building Performance Simulation Association (IBPSA) 2015 Conference, Hyderabad, India, December 7-9, 2015.

PRESENTATIONS:

• "Designing for Circadian Rhythms," Greenbuild 2016, Los Angeles, CA, October 5, 2016 (with E. Clark).

• "Working Smarter and Sleeping Better: Circadian Rhythm in Workplace and Healthcare Design," Metropolis Magazine, Point of view, March 2016.

• "Designing for Circadian Light and health Outcomes in Architectural Practice," 2016 AIBC (Architectural institute for British Columbia), Building a Resilient Future, May 17th, 2016 (with M. Brennan and E. Clark), Vancouver, Canada.

• “Designing for Circadian Friendly Built Environments,” 3 hour workshop, Lightfair International, Lightfair Institute, San Diego, CA, April 24-28, 2016 (with M. Brennan and E. Clark).

LINKS:

Links to relevant other research and publications:Sky Spectra Models / HDR_Circadian capture

MEASURING THE SKY SPECTRA

We installed a spectrophotometer the roof of Gould Hall at the University of Washington to measure the spectral variability of the Seattle skies. The data collection started in June 2021. The equipment (Ocean Insight Flame VIS-NIR Spectrometer) and its installation is funded by ZGF Architects and the University of Washington, College of Built Environments, Applied Research Consortium.

SKY SPECTRA MODELS

PUBLICATIONS:

• Inanici M, Abboushi B, and Safranek S. “Evaluation of Sky Spectra and Sky Models in Daylighting Simulations,” Journal of Lighting Research and Technology, 2022.

• Inanici M. “Improving the Accuracy of Spectral Daylighting Simulations in Buildings,” Technical report prepared for the Pacific Northwest National Laboratory (Department of Energy), Integrated Daylighting, Electric Lighting, and Controls Research, September 2020.

• Inanici M. "Focusing on Daylight Spectra", Illuminating Engineering Society (IES), Forum for Illumination Research, Engineering, and Science (FIRES), August 2019.

• Inanici M. "Tri-stimulus Color Accuracy in Image-based Sky Models: Simulating the Impact of Color Distributions throughout the Sky Dome on Daylit Interiors with Different Orientations", IBPSA 2019 Conference, Rome, Italy, September 2-4, 2019.

Spectral properties of daylight surpasses any other light source. Its dynamic intensity and spectra across the full spectrum facilitates sustainable daylighting practices, produces best color rendition, and regulates circadian rhythms in all living beings. However, simulation models do not typically include spectral variability; daylight is modelled as a uniform, equal energy white source. In this paper, tristimulus calibration procedures are utilized to create spectrally accurate High Dynamic Range (HDR) photographs. HDR photographs of skies are collected and utilized as an input to image based lighting (IBL) simulations. The impact of color variations across the sky dome and between different sky conditions are studied. Per-pixel photopic luminances, tri-stimulus chromatic distributions, Correlated Color Temperatures (CCT) and circadian luminance and illuminance values are quantified for image-based daylighting simulations, and compared with standard colorless Perez skies.

LINKS:

Links to relevant other research and publications: Sky Models / Image based sky models

DAYLIGHTING AND ELECTRIC LIGHTING ANALYSIS OF HAGIA SOPHIA USING HIGH DYNAMIC RANGE PHOTOGRAPHY TECHNIQUE AND SIMULATION

The lighting quality in Hagia Sophia has been a topic of interest for centuries among visitors, writers, poets, and researchers. In fact, almost all literature on Hagia Sophia includes a brief statement on its daylighting and sunlighting. In these documents lighting is defined as “poetic”, “magical” and “mystical”. Yet, there were not any comprehensive quantitative studies on Hagia Sophia’s lighting. The objectives of this research is:

1) To study the interior luminance values, luminance distribution patterns and luminance ratios in Hagia Sophia under naturally occurring sky conditions(the factors that are instrumental for creating the unique luminous environment in Hagia Sophia are discussed).

2) To study the electric lighting in conjunction with the daylighting in Hagia Sophia (the impact of electric lighting on the ambient light levels and luminance distribution patterns is evaluated during daylight hours).

PUBLICATIONS:

• Noback A, Grobe L, and Inanici M. “Pools of light: Illumination by directional sunlight in Hagia Sophia,” Proceedings of the International Hagia Sophia Symposium II; History of an Old Monument, FSMVU Center for Hagia Sophia Studies, Istanbul, Turkey, May 27-29, 2022.

• Noback A, Grobe L, and Inanici M. “Hagia Sophia’s Sixth Century Daylighting,” Proceedings of the International Hagia Sophia Symposium, Istanbul, Turkey, 687-706, September 24-25, 2020.

• Grobe L, Noback A, and Inanici M. “Challenges in the Simulation of Daylighting Distribution in Late Antique Hagia Sophia,” Proceedings of the International Hagia Sophia Symposium, 661-685, September 24-25, 2020.
  

• Inanici M. Lighting Analysis of Hagia Sophia. Annuals of Hagia Sophia Museum: No. 17, Istanbul: December 2014, 128-202 (English/Turkish). © Hagia Sophia Museum, online version republished here with permission.

• Inanici M. Demystifying Ancient Wisdom: Lighting in Hagia Sophia. Faculty Views on Arch(BE]Log. Arch [BE] Log is a blog and forum for current students, alumni, and faculty at the University of Washington, Department of Architecture, 2013.

PRESENTATIONS:

Grobe L, Noback A, and Inanici M. "Perspectives on light scattering by window glass in Hagia Sophia," Forum Art of the Middle Ages, September 27, 2024, Friedrich Schiller University, Jena, Germany (presented by Grobe).

LINKS:

Links to relevant other research and publications: HDR photography / Extrapolation

MEASURING CIRCADIAN LIGHTING WITH HIGH DYNAMIC RANGE PHOTOGRAPHY

PUBLICATIONS:

• Jung BY and Inanici M. “Measuring Circadian Lighting through High Dynamic Range Photography,” Lighting Research and Technology, 51(5): 742-763, 2019. https://doi.org/10.1177/1477153518792597.

The human ocular system functions in a dual manner. While the most well-known function is to facilitate vision, a growing body of research demonstrates its role in resetting the internal body clock to synchronize with the 24-hour daily cycle. Most research on circadian rhythms is performed in controlled laboratory environments. Little is known about the variability of circadian light within the built and natural environments. Currently, very few specialized devices measure the circadian light, and they are not accessible to many researchers and practitioners. In this paper, tristimulus colour calibration procedures for high dynamic range photography are developed to measure circadian lighting. Camera colour accuracy is evaluated through CIE trichromatic (XYZ) measurements; and the results demonstrate a strong linear relationship between the camera recordings and a scientific-grade colorimeter. Therefore, it is possible to correct for the colour aberrations and use high dynamic range photographs to measure both photopic and circadian lighting values. Spectrophotometric measurements are collected to validate the methodology. Results demonstrate that measurements from high dynamic range photographs can correspond to the physical quantity of circadian luminance with reasonable precision and repeatability. Circadian data collected in built environments can be utilized to study the impact of design decisions on human circadian entrainment and to create guidelines and metrics for designing circadian friendly environments.

PRESENTATIONS:

• Jung, B. "Workshop on Melanopic HDR Capture," Radiance Workshop 2022, Toronto, Canada.
• Inanici M. "Measuring and Analyzing the Circadian Light: A Discussion on Units, Metrics, and Techniques," Presentation at DIVA Day 2017,Berkeley, CA.

• Jung BY, Inanici M. "Capturing the Circadian Lighting Through HDR Photography," Radiance Workshop 2017, Portland, OR.

LINKS:

Links to relevant other research and publications: HDR photography / Lark

COMPUTING LONG TERM LUMINANCE MAPS FROM LIMITED NUMBER OF HDR IMAGERY

PUBLICATIONS:

• Liu Y, Colburn A, and Inanici M. “Deep Neural Network Approach for Annual Luminance Simulations,” Journal of Building Performance Simulation, 13(5): 532-554, 2020.

Annual luminance maps provide meaningful evaluations for occupants’ visual comfort and perception. This paper presents a novel data-driven approach for predicting annual luminance maps from a limited number of point-in-time high-dynamic-range imagery by utilizing a deep neural network. A sensitivity analysis is performed to develop guidelines for determining the minimum and optimum data collection periods for generating accurate maps. The proposed model can faithfully predict high-quality annual panoramic luminance maps from one of the three options within 30 min training time: (i) point-in-time luminance imagery spanning 5% of the year, when evenly distributed during daylight hours, (ii) one-month hourly imagery generated during daylight hours around the equinoxes; or (iii) 9 days of hourly data collected around the spring equinox, summer and winter solstices (2.5% of the year) all suffice to predict the luminance maps for the rest of the year. The DNN predicted high-quality panoramas are validated against Radiance renderings.

• Liu Y, Colburn A and Inanici M. "Predicting Annual Equirectangular Panoramic Luminance Maps Using Deep Neural Networks", IBPSA 2019 Conference, Rome, Italy, September 2-4, 2019.

This paper presents a novel method to accelerate annual luminance-based evaluations utilizing a deep neural network (DNN). From a small subset (5%) of high dynamic range (HDR) imagery, our method can predict annual panoramic luminance maps (with 360-degrees horizontal and 180-degrees vertical field of view) within an hour. Unlike the fixed camera viewpoint of perspective or fisheye projections that are commonly used in daylighting evaluations, panoramas allow full degree-of-freedom in camera roll, pitch, and yaw, thus providing a robust source of information for an occupant’s visual experience in a given environment. The DNN predicted high-quality panoramas are validated against Radiance RPICT renderings using a series of quantitative and qualitative metrics. With the developed workflow, practitioners and researchers can incorporate long-term luminance-based metrics over multiple view directions into the design and research process without the lengthy computing processes.

• Liu Y, Colburn A and Inanici M. "Computing Long-term Daylighting Simulations from High Dynamic Range Imagery using Deep Neural Networks", 2018 Building Performance Analysis Conference and SimBuild, co-organized by ASHRAE and IBPSA-USA. Chicago, IL, September 26-28, 2018.

This paper describes the development of a novel prediction model to generate annual luminance maps of indoor space from a subset of images by using deep neural networks (DNNs). This paper describes the development of a novel prediction model to generate annual luminance maps of indoor space from a subset of images by using deep neural networks (DNNs). This model can be applied to accelerate annual luminance-based simulations and lays the groundwork for generating annual luminance maps utilizing High Dynamic Range captures of existing environments.

Computing Long-term Daylighting Simulations from High Dynamic Range Imagery using Deep Neural Networks received the Best paper Award in the 2018 Building Performance Analysis Conference and SimBuild, co-organized by ASHRAE and IBPSA-USA.

• Inanici M. “Dynamic Daylighting Simulations from Static High Dynamic Range Imagery using Extrapolation and Daylight Coefficient Methodologies,” International Building Performance Simulation Association (IBPSA) 2013 Conference, Chambery, France, August 25-28, 2013.

This paper describes the development of a technique for extrapolation of dynamic daylighting simulations from a limited number of high dynamic range photographs.  This technique allows us to photographically capture and measure per-pixel lighting quantities from existing spaces in a limited time frame; and the measured information is used to establish a statistics based daylight coefficient model for the studied scene. It negates the need to explicitly model the geometry, material and lighting properties in existing environments, as they would be required in a typical simulation and daylight coefficient computation. Statistics based daylight coefficients can be used to perform daylighting simulations under any generic, arbitrary or any physically occurring sky conditions.

PRESENTATIONS:

• Liu Y, Inanici M, and Colburn A. "Computing Long-term Daylighting Simulations from High Dynamic Range Photographs Using Deep Neural Networks," Radiance Workshop, Portland OR, August 22-23, 2017.

• Inanici M. “Prediction of Dynamic Daylighting Simulations from a Limited Number of High Dynamic Range Photographs”, Presented at the 4th DIVA Day: DIVA for Rhino (Environmental Performance Analysis in Design Practice + Research) Seattle, October 2, 2014.

COLLABORATIONS

PUBLICATIONS:

• Chmielinski M, Yost M, Cohen M, Inanici M, Simpson C. “Non-Ionizing Radiation Modeling to Predict Ambient Irradiance in Work Areas at an Indoor Cannabis Farm,” Annals of Work Exposures and Health, 2023. https://doi.org/10.1093/annweh/wxad048.

• Ko WH, Schiavon S, Altomonte S, Andersen M, Batool A, Browning W, Burrell G, Chamilothori K, Chan YC, Chinazzo G, Christoffersen J, Clanton N, Connock C, Dogan T, Faircloth B, Fernandes L, Heschong L, Houser KW, Inanici M, Jakubiec A, Joseph A, Karmann C, Kent M, Konis K, Konstantzos I, Lagios K, Lam L, Lam F, Lee E, Levitt B, Li W, MacNaughton P, Malekafzali-Ardakan A, Mardaljevic J, Matusiak B, Osterhaus W, Petersen S, Piccone M, Pierson C, Protzman B, Rakha T, Reinhart R, Rockcastle S, Samuelson H, Santos L, Sawyer A, Selkowitz S, Sok E, Strømann-Andersen J, Sullivan WC, Turan I, Unnikrishnan G, Vicent W, Weissman D, Wienold J. “Window View Quality: Why It Matters and What We Should Do,” Leukos, the Journal of the Illuminating Engineering Society, 18(3): 2022, 259-267. https://doi.org/10.1080/15502724.2022.2055428

• Parsaee M, Demers CM, Lalonde JF, Potvin A, Inanici M, and Hébert M. “Biophilic Photobiological Adaptive Envelopes for Sub-Arctic Buildings: Exploring Impacts of Window Sizes and Shading Panels’ Color, Reflectance, and Configuration”, Solar Energy, 220: 802-827, 2021. https://doi.org/10.1016/j.solener.2021.03.065

• Parsaee M, Demers CM, Lalonde JF, Potvin A, Inanici M, and Hebert M. “Human-centric Lighting Performance of Shading Panels in Architecture: A Benchmarking Study with Lab Scale Physical Models under Real Skies,” Solar Energy, 204: 354-368, 2020. https://doi.org/10.1016/j.solener.2020.04.088

DAYLIGHT DRIVEN CIRCADIAN LIGHTING DESIGN

In this research, the groundwork is established to start to create a set of guidelines to help architects and designers maximize the potential for daylight to provide circadian stimulus at the earliest stages of a project. This is accomplished through a series of lighting simulations that explore and test various architectural parameters that affect daylight-driven circadian lighting, with simultaneous consideration given to photopic lighting availability and visual comfort. The architectural parameters tested in this study included window head height, building orientation, shading devices, visual obstructions to the sky, and room depth. The results show that informed design decisions could maximize circadian potential in a given space, while achieving visually satisfactory luminous environments.

PUBLICATIONS:

• Altenberg Vaz N and Inanici M. “Syncing with the Sky: Daylight-Driven Circadian Lighting Design,” Leukos, the Journal of the Illuminating Engineering Society, 17(3): 291-309, 2021.

LINKS:

Links to relevant other research and publications: Lark / Sky Spectra

COMPARISON OF SKY MODELLING PRACTICES AND SIMULATION TECHNIQUES

PUBLICATIONS:

• Inanici M. and Hashemloo A. "An investigation of the daylighting simulation techniques and sky modeling practices for occupant centric evaluations", Building and Environment, 113: 220-231, 2017.  

Occupant centric performance approaches in daylighting studies promote design decisions that support human visual comfort, productivity, and visual preferences, along with more conventional energy efficiency criteria. Simulating per-pixel luminance values and luminance distribution patterns for the entire scene allows us to analyze the occupant centric metrics and performance criteria. However, there are a number of different sky models, complex fenestration models, and simulation techniques that produce either conventional point in time images or annual luminance maps. This paper discusses the similarities and differences between different techniques; and a comparison analyses provides insight about their impact on occupant centric lighting measures. The comparisons for sky modeling include the conventional CIE skies (Clear, Intermediate, and Overcast), measurement based CIE models, Perez all-weather skies, and high dynamic range image based skies. The comparison of simulation techniques include point in time simulations, image based lighting simulations, and annual luminance simulations (three-phase and five-phase methods). Results demonstrate that measurement based sky models match real world conditions with reasonable proximity, and generic CIE skies consistently underestimate the indoor lighting conditions. Annual simulation methods provide a large database of temporal luminance variations, where individual instances are comparable to point in time simulations. Long term luminance simulations provide opportunities to evaluate the percentage of the year that a given luminance based criteria is met or violated.

Inanici M. and Liu Y. “Robust Sky Modelling Practices in Daylighting Simulations,” Passive and Low Energy Architecture (PLEA) 2016 Conference, Los Angeles, CA, July 11-13, 2016.

The demand for more sustainable building practices prompted the use of more analytical tools in the design processes. This research addresses a need to compare various sky models used in daylighting practices. The sky models can be mathematical or image based; they can be generic or measurement based. The selection of the right model depends on the scope of the simulation. It is recommended to use generic CIE models only for basic comparisons. When generated or calibrated with diffuse and direct irradiance values, CIE, Perez, and image based sky models yield to comparable results. Image based sky models are most useful to capture the local conditions that include the complexities of clouds and solar corona, surrounding urban fabric and forestry.

LINKS:

Link to relevant other research and publications: Image Based Skies / hdrscope / HDRI / Extrapolation

HIGH DYNAMIC RANGE PHOTOGRAPHY AS A LUMINANCE MAPPING TECHNIQUE

The potential, limitations, and applicability of the High Dynamic Range (HDR) photography technique is evaluated as a luminance mapping tool. Multiple exposure photographs of static scenes are taken with a  digital camera to capture the wide luminance variation within the scenes. The camera response function is computationally derived using the Photosphere software, and is used to fuse the multiple photographs into HDR images. The vignetting effect and point spread function of the camera and lens system is determined. Laboratory and field studies have shown that the pixel values in the HDR photographs can correspond to the physical quantity of luminance with reasonable precision and repeatability.

PUBLICATIONS:

• Jakubiec A, Inanici M, van den Wymelenberg K, Mahic A. “Improving the Accuracy of Measurements in Daylit Interior Scenes using High Dynamic Range Photography,” Passive and Low Energy Architecture (PLEA) 2016 Conference, Los Angeles, CA, July 11-13, 2016.

• Jakubiec A, van den Wymelenberg K, Inanici M, Mahic A. “Accurate Measurement of Daylit Interior Scenes using High Dynamic Range Photography,” CIE (International Commission on Illumination) 2016 Lighting Quality and Energy Efficiency Conference, Melbourne, Australia, March 3-5, 2016.

• Inanici MN. “Evaluation of High Dynamic Range Photography as a Luminance Measurement Technique”, Journal of Lighting Research and Technology, Vol. 38, no. 2, June 2006, pp. 123-126.

  Evaluation of High Dynamic Range Photography as a Luminance Measurement Technique has been selected as one of the 25 "classic" papers in the 50th volume of journal of Lighting Research and Technology (January 2018). In their paper, Boyce (editor in chief) and Carter (immediate past chairman of LRT) has selected 25 papers that "can be regarded as classics, in the sense that they have either initiated an area of research, completed an area of research, or, when the topic is active, have been frequently cited".

  UW Architecture news: http://arch.be.uw.edu/democratized-data-classic-research/

• Inanici MN . “Per-pixel Data Acquisition with High Dynamic Range Photography” International Commission on Illumination (CIE) 2005 Conference, Leon, Spain, 18-20 May, 2005.

• Inanici MN and Galvin J. Evaluation of High Dynamic Range Photography as a Luminance Mapping Technique. Lawrence Berkeley National Laboratory, LBNL Report # 57545, 2004. Available from: University of California eScholarship Repository and LBNL Library.

PRESENTATIONS:

• Inanici M. “The play of Light, Shadows, and Reflections: Capturing the Luminous Environment, Understanding the Human Visual Comfort,” Saint Gobain Daylighing Community Program, Paris, France, June 28th, 2017.

• Workshop, “Introduction to High Dynamic Range Photography,” 3 hour workshop (with A. Jakubiec), PLEA Conference, Los Angeles, CA, July 13, 2016

• Workshop on “Use of High Dynamic Range Photography in Lighting Research and Practice (Part 1: HDR Image Capture; Part2: HDR Image Analysis; Part3: HDR Image Display; Part 4: Applications),” IlumiNa 2015: International Workshop on Advanced Daylighting Simulation, Concepcion, Chile, March 20, 2015.

• Inanici M. “Introduction to High Dynamic Range Photography”, Presented at the 8th International Radiance Workshop, Harvard Graduate School of Design, Cambridge, MA, 2009.

• Inanici M. “Recording Light: High Dynamic Range Imagery,” 3 hour workshop, Lightfair International, Lightfair Institute, Las Vegas, NV, May 26, 2008.

• Inanici M. “High Dynamic Range Imaging,” 3 hour workshop, Lightfair International, Lightfair Institute, New York, NY, 2007.

APPLICATIONS:

Daylighting the New York Times Headquarters Building Low Glare Outdoor Luminaire: California Energy Commission’s Public Interest Energy Research (PIER) Buildings Program New Lighting Solutions for High-Bay Spaces: High-output T5 Lamps and Luminaires- Federal Energy Management Program (FEMP) Focus, Fall 2004.

ACKNOWLEDGEMENTS:

"Evaluation of High Dynamic Range Photography as a Luminance Measurement Technique" was funded by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Building Technology, Building Technologies Program of the U.S. Department of Energy under Contract No. DE-AC03-76SF00098.

LINKS:

Link to relevant other research and publications: Image Based Skies / hdrscope / Extrapolation / Hagia Sophia

hdrscope

This paper describes the development of a new tool called hdrscope that enables users to perform qualitative and quantitative lighting analysis via per-pixel methods. Using a simulated and photographically captured lab space as a case study, per-pixel analysis methods are described, challenges associated with per-pixel lighting analysis are discussed, and hdrscope analysis techniques are demonstrated. hdrscope is intended to lower the entry barrier for lighting professionals, and to facilitate the utilization of lighting analysis in early design and development stages as well as post occupancy. It also provides a user friendly tool for lighting experts while filling in the gaps among the current lighting analysis tools.

PUBLICATIONS:

• Kumaragurubaran V. and Inanici M. “hdrscope: High Dynamic Range Image Processing Toolkit for Lighting Simulations and Analysis,” International Building Performance Simulation Association (IBPSA) 2013 Conference, Chambery, France, August 25-28, 2013.

SOFTWARE:

• hdrscope: High Dynamic Range image processing and analysis for architectural lighting design.

LINKS:

Link to relevant other research and publications: Image Based Skies / hdrscope / Extrapolation / Hagia Sophia

DEVELOPMENT AND EVALUATION OF IMAGE BASED SKY MODELS FOR DAYLIGHTING APPLICATIONS

This research demonstrates the use of High Dynamic Range (HDR) fisheye images of the sky dome in lighting simulations. The objective is to improve the accuracy of simulations with site specific sky conditions. The luminance information stored at a pixel level in an HDR photograph is used to light the simulated environment through an Image Based Rendering (IBR) technique. The results show that image based sky models can provide a more accurate and efficient method for defining the sky luminance distributions and the impact of surrounding urban fabric and vegetation as compared to generic CIE sky models and explicit modeling of surrounding urban fabric and forestry.

PUBLICATIONS:

• Inanici M. “Evaluation of High Dynamic Range Image-based Sky Models in Lighting Simulation,” Luekos, Journal of the Illuminating Engineering Society (IES), 7(2), October 2010, 69-84.

• Inanici M. “Applications of Image based Rendering in Lighting Simulation: Development and Validation of Image based Sky Models”, Proceedings of the 11th International Building Performance Simulation Association (IBPSA) Conference, July 27-30, 2009, Glasgow, UK.

PRESENTATION:

• Inanici M. “Applications of Image based Rendering in Lighting Simulation”, Presented at the 8th International Radiance Workshop, 2009, Cambridge, MA.

ACKNOWLEDGEMENT:

This work was funded by the University of Washington Royalty Research Fund (2009-2010).

DATA:

HDR sky images were captured for one day in every month between December to June (winter solstice to summer solstice) at 15 minute intervals during daylight hours. The database includes images from December 28, 2009 (32 image sets), Jan 31, 2010 (38 image sets), Feb. 20, 2010 (43 image sets), March 27, 2010 (49 image sets), April 25, 2010 (48 sets), May 23 (43 image sets), and June 22 (53 image sets). The dates were chosen around the 21st of each month. Dates vary to allow capturing varying weather conditions and to avoid inclement weather (to prevent equipment damage). The database covers a wide range of possible sun angles and sky conditions for Seattle.

 

LINKS:

Link to relevant other research and publications: HDRI / hdrscope / Extrapolation

GlareShade: A VISUAL COMFORT BASED APPROACH TO OCCUPANT CENTRIC SHADING SYSTEMS

This paper presents a novel method for designing of an occupant-centric shading algorithm that utilizes visual comfort metric as the form-generating criteria. Based on the premise of previous studies that demonstrate glare as the most important factor for operating shading devices, GlareShade is introduced as a simulation-based shading methodology driven by occupant’s visual comfort. GlareShade not only responds to changing outdoor conditions such as the movement of the sun and the variation of cloud cover, but it also accounts for building specific local conditions. GlareShade draws its strength and flexibility from an occupant-centric approach that is based on the visual field of view of each occupant as the occupant is performing common visual tasks in a given environment, and the developed shading system is linked to a distributed sensing network of multiple occupants. ShadeFan is demonstrated as a proof-of-concept dynamic shading system utilizing the GlareShade method.

• Hashemloo AR, Inanici, M, Meek C. "GlareShade: A Visual Comfort-based Approach to Occupant-centric Shading Systems," Journal of Building Performance Simulation, 2015.

LUMINANCE DISTRIBUTION PATTERNS AND GLARE: HUMAN VISUAL COMFORT METRICS

• van den Wymelenberg K and Inanici, M. "Evaluating a New Suite of Luminance-Based Design Metrics for Predicting Human Visual Comfort in Offices with Daylight," Leukos: The Journal of the Illuminating Engineering Society of North America, 2015. DOI: 10.1080/15502724.2015.1062392 [pdf]

• van den Wymelenberg K and Inanici M. “A Critical Investigation of Common Lighting Design Metrics for Predicting Human Visual Comfort in Offices with Daylight,” Leukos: The Journal of lluminating Engineering Society of North America, 10(3), 145-164, 2014. [pdf]

• van den Wymelenberg K and Inanici M. “Limitations of Common Lighting Metrics for Evaluating Human Visual Comfort in Spaces with Daylight,” Illuminating Engineering Society (IES) 2013 Conference, Huntington Beach, CA, October 26-29, 2013.

• van den Wymelenberg K, Inanici M and Johnson P. “The Effect of Luminance Distribution Patterns on Occupant Preference in a Daylit Office Environment,” Luekos, Journal of the Illuminating Engineering Society (IES), 7(2), 103-122, 2010. [pdf]

• van den Wymelenberg K and Inanici M. “A Study of Luminance Distribution Patterns and Occupant Preferences in Daylit Offices,” Proceedings of the Passive and Low Energy Architecture (PLEA) 2009 Conference, Quebec City, Canada, June 22-24, 2009.

LINKS:

Link to relevant other research and publications: HDRI / hdrscope / Per-Pixel

LUMINANCE CONTRAST AS A DEPTH CUE

PUBLICATIONS:

• Tai NC and Inanici M. “Luminance Contrast as Depth Cue: Investigations and Design Applications,” Journal of Computer-Aided Design and Applications, 9(5), 2012, 691-705 [abstract].

• Tai NC and Inanici M. “Space Perception and Luminance Contrast: Investigation and Design Applications through Perceptually based Simulations,” Spring Simulation Multi-conference, Symposium on Simulation for Architecture and Urban Design (SimAUD2010), Orlando, FL, April 12-15, 2010.

• Tai NC and Inanici M. “Lighting in Real and Pictorial Spaces: A Computational Framework to Investigate the Scene based Lighting Distributions and their Impact on Depth Perception,” Association of Computer Aided Design and Research in Asia (CAADRIA) 2010 Conference, Hong Kong, April 7-10, 2010.

• Tai NC and Inanici M. “Depth perception as a function of Lighting, Time, and Spatiality,” Short paper, Illuminating Engineering Society (IES) 2009 Conference, Seattle, WA, November 16-18, 2009.

• Tai NC and Inanici M. “Depth Perception in Real and Pictorial Spaces: A Computational Framework to Represent and Simulate the Built Environment,” Proceedings of the Association of Computer Aided Design and Research in Asia (CAADRIA) 2009 Conference, Yunlin, Taiwan, April 22-25, 2009.

   

PER-PIXEL LIGHTING DATA ANALYSIS

PUBLICATIONS:

• Inanici M. Per-pixel Lighting Data Analysis. Lawrence Berkeley National Laboratory, LBNL Report # 58659. Available from: eScholarship Repository, University of California, and U.S. Department of Energy, Office of Scientific and Technical Information.

• Inanici MN and Navvab M. "The Virtual Lighting Laboratory: Per-pixel Luminance Data Analysis", Luekos - Journal of the Illuminating Engineering Society of North America, 3(2), October 2006, pp. 80-104.

LINKS:

Link to relevant other research and publications: Image Based Skies / hdrscope / HDRI / VLL

NEW METRIC FOR QUANTIFYING THE DIRECTIONALITY OF LIGHT:

DIRECTIONAL - TO - DIFFUSE RATIO

Directionality of light is the balance between the diffuse and directional components within an environment. It has a significant impact on the appearance of 3D objects; and the visual performance and comfort of occupants within that environment. Poor directionality may produce harsh shadows on the task, cause veiling reflections towards the viewing angle, or create a dull environment. Adequate directionality may model 3D surfaces, reveal the surface textures or details of a task, and create an aesthetically pleasing environment. A new metric is derived from the basic definition of directionality: The diffuse and directional components of the luminous environment are isolated as a unique feature of simulation-based approach and the ratio of the directional-to-diffuse light is calculated. The rationale and methodology of the directional-to-diffuse ratio is discussed through visual demonstrations and quantified metrics.

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PUBLICATION:

• Inanici MN. “Computational Approach for Determining the Directionality of Light: Directional-to-Diffuse Ratio”, Proceedings of the 10th International Building Performance Simulation Association (IBPSA) Conference, September 3-6, 2007, Beijing, China, pp. 1182-1188.

VIRTUAL LIGHTING LABORATORY

Virtual Lighting Laboratory (VLL) is an advanced lighting analysis tool and methodology that is based on post-processing of the physically-based renderings. It enhances the integration of the lighting analysis into the architectural design process through computational tools that make the analysis more convenient, accessible, accurate, and rigorous. The research includes the theory, implementation, and application of the virtual meters (luminance meter, illuminance meter, contrast meter, integrating sphere, and colorimeter) as well as the development of unique analysis options and metrics that are pertinent to the computational per-pixel data.

PUBLICATIONS:

• Inanici MN and Navvab M. "The Virtual Lighting Laboratory: Per-pixel Luminance Data Analysis", Luekos - Journal of the Illuminating Engineering Society of North America, 3(2), October 2006, pp. 80-104.

• Inanici MN. Transformations in Architectural Lighting Analysis: Virtual Lighting Laboratory. Dissertation: The University of Michigan, College of Architecture and Urban Planning, 2004. Available from: ProQuest Information and Learning, Ann Arbor , MI ; AAT 3121949.

• Inanici MN. "Transformations of High Dynamic Range Images into Virtual Lighting Laboratories". International Building Performance and Simulation Association (IBPSA) 2003 Conference, Eindhoven, Netherlands, 10-14 August, 2003.

• Inanici MN. "Utilization of Image Technology in Virtual Lighting Laboratory". International Commission on Illumination (CIE) 2003 Conference, San Diego, 26-28 June, 2003.

• Inanici M. “Application of the state-of-the-art Computer Simulation and Visualization in Architectural Lighting Research," Proceedings of the 7th International Building Performance and Simulation Association (IBPSA) 2001 Conference, Rio de Janerio, Brazil, August 13-15, 2001.

PRESENTATION:

• Inanici, M. "Post-processing of Radiance Images: Virtual Lighting Laboratory", 1st International Radiance Workshop, Fribourg, Switzerland, 2002.

LINKS:

Link to relevant other research and publications: Per-Pixel / hdrscope / HDRI

ENERGY EFFICIENT BUILDING DESIGN

PUBLICATIONS:

• Demirbilek N, Yalciner U, Ecevit A, Sahmali E, and Inanici M. “Analysis of the Thermal Performance of a Building Design located at 2465m: Antalya - Saklikent National Observatory Guesthouse,” Building and Environment, 38(1), Jan 2003, pp. 177-184.

• Inanici M and Demirbilek N. “Thermal Performance Optimization of Building Aspect Ratio and South Window Size in Five Cities having Different Climatic Characteristics of Turkey,” Building and Environment, 35(1), Jan 2000, pp. 41-52.

• Demirbilek N, Yalciner U, Inanici M, Ecevit A, and Demirbilek O. “Energy Conscious Dwelling Design for Ankara,” Building and Environment, 35(1), Jan 2000, pp. 33-40.

• Demirbilek N, Sahmali E, and Inanici M. “A Passively Climatized Building, 2500 m Above Sea Level,” Proceedings of Solar'97 - Australian and New Zealand Solar Energy Society, Canberra, Australia, paper 56, Dec. 1-3, 1997.

 

 

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© Mehlika Inanici
Last update: August 2022