Lighting Simulations: A Parametric Perspective. Sarith Subramaniam

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1 Lighting Simulations: A Parametric Perspective Sarith Subramaniam 1

2 Thinking parametrically 2

3 How many reflections are required to simulate venetian blinds? Should I use venetian blinds?

4 Which luminaire should be used? 4

5 I got interested in Parametric Design in late

6 and got introduced to Grasshopper and Honeybee 6

7 (Rhino (Grasshopper (Honeybee ))) 7

8 Daylighting simulation in Rhino with Honeybee through Radiance Simulation Results 8

9 Daylighting simulation in Rhino with Honeybee through Radiance Input Output 9

10 Daylighting can be analyzed and visualized in different ways 10

11 There is more to Honeybee than Daylighting Photovoltaics Computational Fluid Dynamics Energy Thermal Comfort 11

12 food4rhino.com/grasshopper-addons/most-downloaded 12

13 Hacking 13

14 is an Open Source Software github.com/mostapharoudsari/honeybee/graphs/contributors Mostapha Sadeghipour Roudsari (UPenn, Thornton Tomasetti) 14

15 github.com/mostapharoudsari/honeybee/blob/master/license_honeybee_gpl.txt 15

16 Solar radiation on a façade between two time intervals 1 Jan to 31 Dec 3 Apr to 19 Nov etc. 2 Jan, 3 Mar, 6 Nov etc. What is the total radiation when the HVAC system is cooling? Or heating? What is the total radiation on weekdays only? etc 16

17 Solar radiation between two time intervals for specific hours Additions and Deletions to the source-code (excerpt) 17

18 The hacked component extended the functionality of the original 18

19 Some of the hacked components Calculates Annual Sunlight Exposure Automates Glazing Placement Locates Results Filters Weather Data and creates sky definitions 19

20 14 th International Radiance Workshop, Philadelphia August

21 We weren t the only ones interested in Honeybee. (GSD 6480) * (ARCH ) * (ARCH 754) * (A4792) * * (Refers to the course being taught this academic year that incorporates Honeybee in the syllabus). 21

22 .and I wasn t the only one trying to hack it. 22

23 .and I wasn t the only one trying to hack it. 23

24 One of the issues with hacking a live software: keeping up! Hacked Component 24

25 Hacking Developing 25

26 github.com/mostapharoudsari/honeybee/graphs/contributors 26

27 Some hacked components got integrated into the source-code 27

28 Wrote source-code for incorporating luminaires 28

29 facebook.com/rhinoceros4point0/posts/

30 Limitations.. 30

31 Hacking Developing Rewriting 31

32 github.com/ladybug-analysis-tools/honeybee/graphs/contributors 32

33 Support Revit, Rhino (and everything else) Hacking Developing Rewriting 33

34 The beta-version already works on Revit and Rhino youtube.com/watch?v=61gdhcy3rma 34

35 Support Revit, Rhino (and everything else) Cross OS Compatibility Hacking Developing Rewriting 35

36 The beta-version works on Windows and Unix-based systems.. * 36

37 . but Revit and Rhino are only Windows-based *. So why bother? 37

log -S 1 -PP pfvokkzd -x 5532 -y 2718 -dp 4096 -ar 5 -ms 11 -ds.1 -dj.9 -dt.05 -dc.

38 1 core on an 8 core i7 processor (Parallel Processing) Illuminance Luminance 19 hrs, 37 min oconv -w materials.rad LfWl.rad rpict -t 0 -e logfiles/lfwl.log -S 1 -PP pfvokkzd -x y dp ar 5 -ms 11 -ds.1 -dj.9 -dt.05 -dc.75 -dr 3 -ss 16 -st.01 -ab 6 -af ambfiles/lfwl.amb -aa.075 -av lr 12 -lw 1e-5 -ps 1 -pt.04 -as ad av

39 8 cores on an 8 core i7 processor 19 hrs, 37 min 3 hrs, 14 min oconv -w materials.rad LfWl.rad rpict -t 0 -e logfiles/lfwl.log -S 1 -PP pfvokkzd -x y dp ar 5 -ms 11 -ds.1 -dj.9 -dt.05 -dc.75 -dr 3 -ss 16 -st.01 -ab 6 -af ambfiles/lfwl.amb -aa.075 -av lr 12 -lw 1e-5 -ps 1 -pt.04 -as ad av

40 40 cores on a non-dedicated 288 core Xeon cluster 19 hrs, 37 min 3 hrs, 14 min 1 hr, 18 min oconv -w materials.rad LfWl.rad rpict -t 0 -e logfiles/lfwl.log -S 1 -PP pfvokkzd -x y dp ar 5 -ms 11 -ds.1 -dj.9 -dt.05 -dc.75 -dr 3 -ss 16 -st.01 -ab 6 -af ambfiles/lfwl.amb -aa.075 -av lr 12 -lw 1e-5 -ps 1 -pt.04 -as ad av

41 aws.amazon.com/ec2/ 19 hrs, 37 min commission one, hundreds or even thousands of server instances simultaneously complete control of your instances. You have root access to each one 3 hrs, 14 min 1 hr, 18 min 19 hrs or a few minutes (user s choice) 41

42 Support Revit, Rhino (and everything else) Cross OS Compatibility Hacking Developing Rewriting Optimize lighting simulation methods Simplify syntax with abstractions Type and Error Checking Apply Object Oriented Programming (OOP) Implement Recipes Leverage Python to Reduce Effort 42

43 Ambient Caching (Ward, Rubinstein, Clear 1988) A ray tracing solution for diffuse interreflection (Ward 1994) The RADIANCE lighting simulation and rendering system (Ward 2007) Implementation of irradiance caching in RADIANCE (Grynberg 1989) Validation of Radiance 43

44 This scene has direct and diffused light. The model inside Rhino 1844 x 966 pixels 1 Pixel: Red Channel, Green Channel, Blue Channel, Luminance 44

45 Reflections for diffused(ambient) sampling: 0 45

46 Reflections for diffused(ambient) sampling: 0, 1 46

47 Reflections for diffused(ambient) sampling: 0, 1, 2 47

48 Reflections for diffused(ambient) sampling: 0, 1, 2, 3 48

49 Reflections for diffused(ambient) sampling: 0, 1, 2, 3, 4 49

50 Reflections for diffused(ambient) sampling: 0, 1, 2, 3, 4, 5 Convergence (almost) 50

51 Strategy: Store and reuse ambient calculations to reduce computation 51

Photon Caching (Ward, Rubinstein, Clear 1988) A ray tracing solution for diffuse interreflection (Ward 1994) The RADIANCE lighting simulation and rendering system (Ward 2007) Implementation of

52 Photon Caching (Ward, Rubinstein, Clear 1988) A ray tracing solution for diffuse interreflection (Ward 1994) The RADIANCE lighting simulation and rendering system (Ward 2007) Implementation of irradiance caching in RADIANCE (Grynberg 1989) Validation of Radiance (Jensen 2000) Global illumination using photon maps Caustics (Schregle 2007) Daylight simulation with photon maps (Schregle, Wienold 2004) Physical validation of global illumination methods: measurement and analysis 52

53 Photon distribution depends on diffused light and caustics Ambient Photons Caustic Photons Caustics Same image with higher exposure 53

54 Photon distribution depends on diffused light and caustics Ambient Photons Caustic Photons Caustics 54

55 Strategy: Pre-calculate photons and use them for multiple simulations 55

56 Daylight Coefficients (Ward, Rubinstein, Clear 1988) A ray tracing solution for diffuse interreflection (Ward 1994) The RADIANCE lighting simulation and rendering system (Ward 2007) Implementation of irradiance caching in RADIANCE (Grynberg 1989) Validation of Radiance (Tregenza 1983) Daylight coefficients (Reinhart, Herkel 2000) The simulation of annual daylight illuminance distributions a state-of the-art comparison of six RADIANCE-based methods (Reinhart, Walkenhorst 2004) Validation of dynamic RADIANCE-based daylight simulations for a test office with external blinds 56

57 Assumption1: Daylighted spaces are surrounded by a discretized hemispherical sky 57

58 Assumption2: Building geometry and surfaces do not change with time. Sky brightness changes. 58

59 Assumption2: Building geometry and surfaces do not change with time. Sky brightness changes. 59

60 Strategy: Save the geometric relationship between sky patches and the daylighted space in a file. DC DC x Sky at 8 AM 60

61 DC x Sky at 9 AM 61

62 DC x Sky at 10 AM 62

63 DC x Sky at 11 AM 63

64 DC x Sky at 12 PM 64

65 DC x Sky at 1 PM 65

66 DC x Sky at 2 PM 66

67 DC x Sky at 3 PM 67

68 DC x Sky at 4 PM 68

69 DC x Sky at 5 PM 69

Matrix based methods (Ward, Rubinstein, Clear 1988) A ray tracing solution for diffuse interreflection (Ward 1994) The RADIANCE lighting simulation and rendering system (Ward 2007) Implementation of

70 Matrix based methods (Ward, Rubinstein, Clear 1988) A ray tracing solution for diffuse interreflection (Ward 1994) The RADIANCE lighting simulation and rendering system (Ward 2007) Implementation of irradiance caching in RADIANCE (Grynberg 1989) Validation of Radiance (Tregenza 1983) Daylight coefficients (Ward, Mistrick, Lee, McNeil, Jonsson 2011) Simulating the daylight performance of complex fenestration systems using bidirectional scattering distribution functions within Radiance (McNeil, Lee 2013) A validation of the Radiance three-phase simulation method for modelling annual daylight performance of optically complex fenestration systems. 70

71 The path between the space and the sky is split into multiple phases or files. Entire calculation is repeated each time. Calculation time can be reduced by reusing phases 71

72 The split is accomplished by hemispherical sampling. 72

73 The challenge in implementation oconv f materials.rad room.rad > room.oct rfluxmtx v o matrices/%s.vmx I+ -ab 2 ad lw 2e-5 n 4 y 100 objects/glazing.rad i room.oct <points.txt rfluxmtx v ff -ab 4 ad lw 1e-5 c 5000 n 4 objects/glazing.rad skyglow.rad i room.oct > matrices/glazing.dmx epw2wea skies/usa_ny_new.york.city-central.park.94728_tmy_3.epw skies/nyc.wea gendaymtx m 4 skies/nyc.wea > skies/nyc.smx dctimestep h matrices/glazing.vmx tmatrix/clear.xml matrices/glazing.dmx skies/nyc.smx> illuminance_annual.txt 73

74 We started implementing matrix based methods in Honeybee a few months ago. 74

75 Dissertation research Reviewing simulation methods Software development Test hypotheses 75

76 Future work: Investigate relevance through hypotheses driven studies 76

77 Thank you 77

Daylighting Simulations with Radiance using Matrix-based Methods

Daylighting Simulations with Radiance using Matrix-based Methods Sarith Subramaniam October 2017 Disclaimer This document was prepared as an account of work sponsored by the United States Government. While