Below is the official description for each one. If you do plan to attend, feel free to drop me a line via my contact form with ideas and topics you want me to cover in those classes, its always good to get fresh ideas from attendees! See you there!

Autodesk Revit and 3ds Max Design for Lighting and Daylighting simulation

5/7/2012 – 9:00 am to 5:00pm

This session will provide an overview of the tools available to you in the Autodesk products family for exploring, defining and validating lighting projects. Focused on the interoperability of Revit and 3ds Max Design, you will learn what is possible to achieve with Autodesk Revit and 3ds Max Design for electrical lighting design as well as daylighting design.

An overview of the rendering capabilities or mental ray and iray will be provided as well as production oriented strategies to integrate lighting photometry and solar information for lighting studies. Tips and tricks will be provided to support project workflows where the design elements are changing and evolving on a regular basis.

Learning Objectives:

• Get a general overview of BIM technologies applicable to lighting design projects.
• Learn about interoperability strategies to adopt when translating data from one software to another.
• Learn about capabilities and limitations of lighting simulation technologies.
• See production examples used in the context of real projects.

L12D08 - Challenges associated with Weather-Based Annual Daylight Simulations

Co-Speaker: Jack Bailey, One Lux Studio, NYC

5/8/2012 – 9:00 am to 12:00pm

This workshop will walk you through the various challenges associated with annual‐based daylight simulation that we experienced with our projects. From the data collection stage through the validation of weather data, to the development of custom tools to integrate window shades into annual simulation, we will present examples of how to successfully predict a building’s performance with regard to daylighting over a year.

Learning Objectives:

• Become familiar with metrics and guidelines associated with daylight simulation.
• Understand the capabilities and limitations of lighting simulation technologies.
• Gather a knowledge of existing tools for daylight simulation.
• Understand how occupancy and shading devices affect daylight performance.

1. Autodesk Revit and 3ds Max Design for Lighting and Daylighting simulation (Monday all day)
2. Challenges associated with Weather-Based Annual Daylight Simulations (Tuesday a.m.)

The official Lightfair 2012 schedule can be found here

We are trying to do a daylight analysis that includes some frosted glass or “kalwall” style skylights which diffuse the light into the space.  We can get the VLT (Visible Light Transmittance) values easy enough.  However, is there some way to accurately (or semi-accurately) account for the rays being dispersed and spread through the frosted glass? 

Simulating frosted glazing in 3ds Max Design for lighting analysis is doable.  You however need to know how to do it properly.  Here is how:

Some useful background information:

First, as opposed to Radiance, the A&D Material has a few internal “things” going on that you need to be aware.  The most important one is that the A&D Material performs internal energy conservation as follow:

Transmissivity wins over Specular Reflectivity which wins over Diffuse Reflectance.  On top of that, the Transmissivity is weighted against a Specular / Diffuse factor.  This factor is ruled by the Translucent color / weight controls in the interface.

In contrast, in Radiance, one can specify a material that is reflecting 100% diffuse and 100% specular while transmitting 100% of the light, leading to “creating” energy.  This is why the parameters of the Radiance materials cannot be plugged “as-is” in the A&D Material.

Translucent Panels:

We compared translucent glazing simulation in mental ray against radiance and measured data and got convincing results (see image) with the following settings:

Desired Diffuse Transmittance:  0.1621  (16.21% Diffuse – Diffuse Transmittance)

• Treat surface as a single polygon in the model
• A&D Diffuse Level:  0.0
• A&D Diffuse Color:  pitch black  (so no weighting is given to the diffuse reflectance)
• A&D Reflection | Reflectivity Level:  1.0
• A&D Reflection | Reflectivity Color:  pure white (the color is a multiplier, we need it to be 1.0 1.0 1.0)
• A&D Refraction |  Transparency Level:  1.0
• A&D Refraction | Transparency Color:  pure white (the color is a multiplier, we need it to be 1.0 1.0 1.0)
•  A&D Refraction | Translucency Checkbox : ON
• A&D Refraction | Translucency Weight: 1.0  (we want it fully translucent)
• A&D Refraction | Translucency Color:  0.1621 0.1621 0.1621 (the color is a multiplier, we need it to be set to the desied transmissivity level “as-is”, equally for all RGB components)
• BRDF | Custom Reflectivity Function: ON
• BRDF | 0 Deg Refl:  0.0
• BRDF | 90 Deg Refl:  1.0
• BRDF | Curve:  ~5  (we need to approximate a typical Fresnel curve)
• Advanced Rendering Options | Thin-Walled : ON

Some important notes: 

• While the illuminances will carry through properly on light meters, the glazing appearance may not look “natural” in “pretty picture renderings”.   It seems that there is currently a limitation with the appearance of the surface when it is hit by light:  its resulting luminance won’t be correct (AFAIK) so glare analysis based on luminance measurements won’t be convincing.
• The following image shows a graph comparing 3ds max, radiance and measured data.  Ignore the “3ds max 2009 SP1 Initial Submission” curve, this is representing a case where our material settings in 3ds Max where wrong, which we corrected later on – in fact, we forgot to turn off a layer so we had 2 panes of glass on top of each other…).  The green curve is what we need to look at….

This group maintains a database and publishes this data via a program called Optics 5. From Optics 5 you can then export a Radiance Material (*.rad file), which can be interpreted
as mental ray A&D Material parameters.

To convert Optics 5 data into A&D Material suitable for lighting analysis, export a glazing or glass definition as Radiance (*.rad) from Optics 5. You will find this command under File | Export to Radiance File.

Once the file is exported on disk, open it in Notepad and search for a section that looks like this:

void BRTDfunc B530_front
10
0.245 0.281 0.340
0.169 0.197 0.187
0 0 0

The color coefficients (RGB) for the ideal specular reflection corresponds to 0.245 0.281 0.340. The color coefficients for the ideal specular transmission corresponds to 0.169 0.197 0.187. Those values will need to be used as a basis for the mental ray A&D Material.

How to use the provided Microsoft Excel spreadsheet to convert to the mr A&D Material.

To correctly convert specular reflection and transmission from a Radiance material to a mr A&D Material, we need to take into account internal energy conservation methods that are built in the mr A&D Material that are not factored by the Radiance material. In other words, numbers can’t be “plugged-in” as is.

To help you with this task, we developed a Microsoft® Excel® software spreadsheet that will let you do this precisely. The spreadsheet can be downloaded here.

Limitations:

• The Radiance Materials exported from the Optics 5 database does not take into account angular dependency: A Fresnel falloff curve is assumed so metallic-coated glazing systems may be less precisely simulated.
• The Optics 5 database contains optical data measured spectrally. The exported Radiance materials and the A&D materials use RGB colors which are a crude approximation of the visible light spectrum. Therefore, lighting simulations are done within limitations of RGB colors.

It will also control Text objects to display the current Time and Date of the Daylight System:

Here is a video demonstrating its usage:

You can download the tool here.

1. In Revit, go in the 3D view you will export to FBX
2. Edit the Graphic Display Options
3. Specify a Location and Time that matches your project settings, for a single day:

   

4. Export to FBX
5. Import in 3ds Max

Your Daylight System should now match the Revit model in Location and Time.

Always verify your data otherwise your project can go wrong – here are a couple advices on the topic:

IES file can contain wrong information: double check them!

I have once seen a manufacturer using the wrong values in their IES files.  I had to contact them and demonstrate that their data was wrong. It turned out that one of their engineer made a mistake with their database system where North American IES files where published using European measurements. That basically means that errors can come from anywhere in the process. Double check your work!

In the ideal scenario, you need to get a physical sample of the luminaire in your office, measure intensities with an illuminance meter and compare with the IES data provided to you in a simple test scene.

Do the numbers match up?  You are good to go. They don’t match up? Keep reading..

Check the 3ds Max scene units:

This is a typical trap: wrong units, wrong light intensities reported on light meters!

3ds Max and Revit has bugs too!

There is a issue  with the IES file reader that can affect you in rare occasions.  The bug has to do with a certain “feature” of the IES file format that some manufacturers rely on. Let me explain:

The IES file format is divided in two main sections: a header section and a data section:

In the header section, there is a special ”bit” that instruct the software to either use the “raw” data or apply a multiplier to it. For example, a manufacturer might have measured a luminaire only once with a 100W lamp in it. Knowing that the same luminaire with a 200W lamp** would emit twice as much light, the manufacturer could publish a different IES file based on the same measurements and simply state that the “raw” data should be multiplied by a factor of 2.0 by changing this special “bit” in the file as illustrated:

For some reason, 3ds Max and Revit are ignoring this multiplier and always read the “raw” data from the IES files, resulting in incorrect simulations. The work around is to use the built-in multiplier (dimmer) feature of the photometric lights:

Note about linear and area lights:

In many occurences, I am asked to perform lighting analysis reports in spaces designed with cove lights.  Unfortunately, this is still not possible to do precisely - and this problem has not been solved by the industry yet!

  There are currently two major problems with linear and area lights in lighting simulation softwares:

1. First, the IESNA standards for photometric measurements assumes that luminaires are measured from a certain distance, making any calculated points inside this distance mathematically inaccurate. If you search for “Near Field Photometry” or “Far Field Photometry”, you will find plently of information on the subject.
2. Second, 3ds max (and Revit btw, as both share the same code for rendering) still has issues to deal with linear and area lights calculation making them unreliable photometric-wise.

As I write these lines, cove lighting situations cannot be mathematically correct with photometric files in 3ds Max: you will have to do some guess work when working with theses scenarios.

**I know, a 200W lamp does not emit twice as much light than a 100W lamp that was only for keeping the example simple.

HDRI and Photography

With today’s typical hardware, it is not possible to capture a lighting design project in a single shot and get it represented accurately on screen “as-is”.  Accurately meaning “how the eye perceived the project at the time the photo was taken”.  Typical digital display devices cannot display the entire range of luminance that a human eye can perceive. Cameras can’t capture that range of luminance at a same time either.  In technical terms, that is the complex (and how interesting) world of Tone Reproduction or Exposure.

For example, your eye adapts rapidly to a variety of contrasts and your brain condenses all this into a unique image, as if you would apply different brightness and contrasts ratios to individual parts of the image.  By opposition, exposure functions of cameras are applied to entire image at once – so the two worlds don’t match very well.

 The future is in what is called “High Dynamic Range” in computer language, where all luminance levels can be captured, stored and displayed into (expensive) devices.

The lecture describes methods to photograph lighting design projects in such a way that results are as close as possible to the human eye perception. Workflows involving image manipulation programs are discussed and demonstrated. 

The attendee learned how to digitally capture the full range of luminance of any given scene (in our case, lighting design projects) with affordable hardware.  He also learned how to manipulate this data with affordable software to create a digital picture that is closer to his perception of the scene.

HDRI and Qualitative Lighting Simulation

HDR Imaging does not only improve our ability to photograph design projects.  It also allows us to improve our efficiency in lighting simulation workflows.  One can use a 3D rendering software to create one image per light source and combine them together in a compositing application.  The advantage of doing this is that the designer can interactively change the intensity of each layer in real time without re-rendering the model each time.

Typical techniques for achieving this workflow are demonstrated as well.

HDRI and Quantitative Lighting Analysis

HDR Imaging also gives us the possibility to perform advanced Daylighting studies of architectural and urban spaces.  We can use this technology to understand glare issues, yearly or monthly cumulative irradiances and more.

Application examples are shown in this lecture.

The exterior twisted steel ribbon representing a race track created a potential of glare for pedestrians and cars passing near by. My mandate was to help the design team understanding if this was a real issue or not.

With the use of computer simulation, several videos where created demonstrating the effect of the reflection of the direct sunlight on the surroundings of the building to identify glare sources. Simulations for the solstice and equinoxes where performed.

Lighting Consultant: One Lux Studio
Computer simulations: Pierre-Felix Breton

I have participated in the process and contributed to the authoring of the following paper: 3ds Max Design Exposure Validation (pdf – 5835Kb) – which describes the process and results.

This project consisted into developping exterior lighting concepts for the tower of a casino in Quebec City.

Color mixing LED light fixtures where selected for their compact size and ease of control for increased flexibility.

Lighting Design: Martin Gagnon
Conceptual Illustrations, Technical Coordination & Diagrams: Pierre-Felix Breton

Planned in 1840 by architect Richard Upjohn and consecrated five years later, the Trinity Church is one of the oldest church in North America.

Now surrounded by the tall buildings of Wall street in New-York (Upjohn would certainly not have made that prediction!), the construction exposes rich details pertaining to the neo-gothic style: carved stone, sculptures, bronze doors etc.

In March 2001, the city was planning a replacement of the street lighting fixtures. This opened the door for a proposal to illuminate the exterior of the building.

To be able to convince the authorities to accept the project, we created highly detailed lighting simulations with a professionnal 3D lighting simulation package.

One of the most difficult task of the project was to model the church accurately: virtually no data was available, except for a set of hand drawn elevations dating from 1930s!

Unfortunately, the project was put on hold by the 9/11 attacks on the WTC where the church was lightly damaged, although some of the lighting concepts where implemented on the front tower later on.

lighting design:

Martin Shaffer and Associates

lighting studies and simulations:

Pierre-Félix Breton

Established on the UNESCO World Heritage site at the foot of Edinburgh’s Royal Mile, the Scottish Parliament has been completed in 2004.

My involvement with the project consisted into working with the lead lighting designers (OVI, Office for Visual Interaction) on the development of a lighting solution that meets television lighting quality, integrates to the unique architectural space and conforms to the global lighting scheme.

The six committee rooms and the debating chamber where lit with a different lighting layout: each space has a distinct configuration of asymmetric vaulted ceilings, suspension cables, trusses and seating layout.

The location and orientation of the luminaires (800+ total) was determined with a combination of high end analysis tools and custom designed 3d modeling tools (more on this subject in the Autodesk Media and Entertainment 3ds max showcase article – pdf).

The lighting of the debating chamber was a challenge on its own due to its asymmetric vaulted ceiling and visible structural elements.

More than 300 fixtures suspended in clusters are aimed in such a way that broadcast lighting conditions are achieved while no occlusion is happening from the architectural elements.

The lighting system of the committee rooms is mounted into “pockets” carved in the vaulted ceiling.

Each luminaire has a precise location and orientation calculated to not be occluded by the edges of the “pockets” and also meet television lighting requirements for intensity and angle.

architect:

Enric Miralles in collaboration with the Edinburgh practice of RMJM

lighting consultants:

Office for Visual Interaction Inc. (OVI) - Jean M. Sundin, Enrique Peiniger

lighting calculations and aiming planning (broadcast lighting):

Pierre-Félix Breton

photos:

Official page of the Scottish Parliament

see also:

Its impressive height and its envelope – a giant semi-transparent screen made with clusters of glossy ceramic bars – will capture environment lighting during daytime in a totally different manner than during night time.

The lighting concept calls for a very even and subtle gradiation of light from the bottom to the top, with accent lighting on the upper part of the building, on the tip of the mast (to meet FAA regulations) and on the structural elements visible on each side of the facades.

My initial task consisted into illustrating the lighting concept with interactive presentations demonstrating the appearance of the building at different time of the night with custom made presentation tools.

The second part of the project was to specify the exact location, count and aiming angle of the chosen luminaires to meet quantitative light levels required by the lighting concept.

Custom designed reflectors for luminaires where used to acheive a reverse wallwasher effect om the entire facade of the building.

architect:

Renzo Piano Building Workshop in collaboration with FXFOWLE Architects

lighting consultants:

Office for Visual Interaction Inc. (OVI) Jean M. Sundin, Enrique Peiniger

lighting studies, illustrations and simulations:

Pierre-Félix Breton

The addition of a pedestrian walkway and a 3rd lane was done in 1997-1999. This was an opportunity for the local authorities to transform the bridge into a landmark for Nova-Scotia with the installation of decorative lighting system.

My involvement with the project consisted into developing lighting simulations to validate the design assumptions as well as set of marketing imagery to convince the deciders about the validity of the project.

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The bridge was illuminated in a festive event, the night of January 1st 2000 as a New Year gift to the local population.

engineers:

Morris and Richard Consulting Engineers Limited

lighting design:

Rudy Ponce, Cooper Lighting

lighting validation studies:

Pierre-Félix Breton

photos:

Cooper Lighting
Halifax Dartmouth Bridge Commission

Lighting Design: Martin Gagnon
Conceptual Illustrations, Technical Coordination & Diagrams: Pierre-Felix Breton

A first phase of my work consisted into producing illustrations of various scenarios for the lighting concept of the spires.

The second phase was more technically oriented: lighting requirements called for the creation of a linear gragation of light that goes from 15fc at the base of the spire, to 5fc in the center to 15fc again at the top.

A complete aiming diagram was produced for the spires after having conducted precise lighting analysis studies performed with custom designed tools.

Lighting Design:
Office for Visual Interaction Inc. (OVI)

Conceptual illustrations and Lighting engineering:
Pierre-Felix Breton

MacroScript files for 3ds Max Design 2009 created to improve the workflow of lighting analysis projects.

The first one will be on the topic of Daylight Simulation  with 3ds Max Design 2010. The second one will be about strategies to estimate optical characteristics of surface finishes for accurate renderings.

Daylight and Lighting Analysis with Autodesk® 3ds Max® 2010:

• How to predict lighting levels in a scene lit with daylight or electric light
• Finding correct values of reflectance and transmittance for the building materials you create and using these values in a lighting render of an existing building
• Importing and using the correct photometric information for a particular manufacturer’s light fitting
• Creating animated daylight simulation studies and experiencing your building in a dynamic way
• Limitations of lighting analysis programs
• Using MAXScript to perform advanced lighting analysis tasks

Capture and Acquire Appearances of Real World Materials for Improved Accuracy in Renderings:

• Rendering engines and color
• Gamma Correction and Linear Workflow
• Color acquisition devices comparison
• Measuring optical characteristics of materials in an affordable way
• Using this data correctly in Physically Based rendering engines

 
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