Building and Simulating a Task Lighting Model in LightTools · Building and Simulating a TaskBuilding and Simulating a Task Lighting Model in LightTools ... Introduction to LightTools

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Introduction to LightTools TrainingTask Lighting ● Page 1

Copyright © 2012 Synopsys, Inc.

Building and Simulating a TaskBuilding and Simulating a Task Lighting Model in LightTools

© Synopsys 2012 1 Introduction to LightTools, “Task Lighting”

Walkthrough Example• This is an example of

modeling a task lighting system in LightTools. You

Goals:Get familiar with basic controls and settings

will follow along with the instructor. The example will make you familiar with most basic LightTools features and the user interface (UI).

Import CAD geometrySet surface properties and finishesAdd light sourcesAdd receiversSimulate the system performance


performanceGenerate a photorealistic rendering of the lit system

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Walkthrough1 2 3

Import Geometry Set Surface Properties Add Sources

456


Photoreal Rendering (unlit)Photoreal Rendering (lit)

Add Receivers and Run

Simulation

Importing Geometry• Go to File > Import > STEP• Using the file dialog box, locate the

“Task Lighting.step” in the“Introduction to LightTools\WorkshopFiles” folder

The base model is supplied as a STEP file. You need to use the STEP data exchange option to import the model into LightTools. WorkshopFiles folder

• Accept default options in the data exchange dialog, click OK

• Press Fit icon ontoolbar

gData Import commands are located under the “File” menu


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Repair Geometry• Select all the imported

parts (Edit > Select All) and use Repair to heal the geometry

Default repair operation attempts to do the following

Substitute analytic ea t e geo et ysurfaces for splinesFill gapsCombine adjacent surfaces into a continuous surface


Repair

User Interface: Tabbed ViewsDialog boxes appear in separate windows, and can move outside of the main LightTools window

Views appear full size on separate tabs; left-click on tab and drag to reorder tabs

Autohide window control

OFF: full window remains always in front

ON: window rolls up to title bar


ponly unless cursor is on top

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User Interface: Floating ViewsSelect Tools > Options, Layout tab (or Window > Floating Views) for resizable view windows


Viewing and Setting Units• Zoom (Mouse Wheel) and Rotate (Right

Mouse Button + <Ctrl>) the model with the mouse. You can also use Zoom buttons and Alignment buttons on the toolbar

Preferences allow you to change the default system settings such as units, optical properties, and view parameters. After changing the preferences

• The STEP model was created with units of “Millimeters”. Go to Edit > Preferences, General Preferences > System and confirm that the current LightTools are set to “Millimeters.”

After changing the preferences you can retain them for future models by saving them. Right click to choose the Save option.

Zoom Align


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Rename Objects• Identify each object by selecting it

in the 3D View. Rename as shown in the picture. The default names during data exchange are arbitrary.

The name of an object is unique in LightTools, and it is used to identify the object graphically and programmatically (macro). Select names so that you canSelect names so that you can easily identify each object in the model.Right-Click in the System Navigator to rename an object

Box_L

Box_R

BackWall

MWFrame

Microwave


Base

Surface Properties• Assign basic optical properties

for the geometry. The picture shows the property assigned for each surface important for the i l ti

Surface Properties for objects can be set using the Optical Property ManagerAn optical property can be shared by many zones

simulation• Settings shown on next slide

Optical properties are defined for zones, which are part of a given surface. The BareSurface is the default zone for any surface. Additional zones can be added using property zones

Use the right-click menu to assign optical properties for a given property

Absorber (Optical)


Lambertian Scatter (Diffuse)

Mirror

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Optical Property Manager - 1• Use Edit>Optical Properties to access optical property

manager


Optical Property Manager - 2• Use Optical Properties tab to define the property you

want


The number in parenthesis (n) indicates the number of surfaces using this optical property

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Optical Property Manager - 3• Usage tab shows all zones using a given property• Use sub selection to reassign


Example: Change all “Cylinder” surfaces to a different property “Mirror”

Optical Property Manager - 4• Color tab allows you to define custom colors for the

optical property


Use View>Surface Color>By Optical Property to switch from default rendering mode (By Refract Mode)

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Create Optical Properties• Create 3 new optical properties and assign their

properties


Details for Each Property

Absorber

Mirror (5%)


Diffuser (40%)

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Assign Properties to Objects• For multiple surfaces/zones, use right-click menu• Repeat property assignment for other surfaces/zones


You can also assign optical properties through the properties dialog box

Model Rendering

View>Surface C l >B O ti l

View>Surface C l >B R f t


Color>By Optical Property(use your own colors)

Color>By Refract Mode(Fixed)

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Introduction to LightTools TrainingTask Lighting ● Page 10Copyright © 2012 Synopsys, Inc.

Hide the Geometry• Before adding the LED we will

hide temporarily hide the geometry

• In the Navigation Tree select all

The Hide function allows you to keep the selected geometry from being displayed in the 3D Design ViewTh hidd t till

gthe geometry

• Right-click and select Hide > All

The hidden geometry still participates in all ray tracingThe icon in the Navigation Tree is shown in grey for any hidden geometryOn the Edit menu you can find controls to Show All and Swap Hidden/ Visible


The Hide control is in addition to any Layer visibility settings

Light Sources• We will use 3 LEDs to illuminate the model

– Manufacturer: OSRAM– Model LUW-W5AM

(Golden DRAGON plus)– Color: White

LED Library provides hundreds of LED models from various vendorsIt allows you to use the LED model in various modes

– Lumens: 100.5– CRI: 80

• This LED model is available in the LightTools LED Library (Tools > LED Library)

model in various modesGeometry OnlyGeometry + ApodizationGeometry + Ray Data

Note: the default ray data file has only 5000 rays. If you need the full ray set then you need to download the ray file from the vendor For this


from the vendor. For this exercise we will use the geometry + apodization mode

LEDs will be placed here

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Select LED• We will load the LED model from the library

and make 2 copies to create additional sources

When you click Create LED the library will add the LED model to the 3D DesignThe default location of the LED will be X=Y=Z=0 (i.e., global origin)The geometry is non-traceableUnits = mm


Units mmLED is created as a group of multiple objects

Examine LED• Wait for the LED Library to finish adding the LED• Close the LED Library• Use the Fit button on the Tool Bar to zoom in on the

LED


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Copy the LED• Zoom the 3D Design

View out slightly using the mouse wheel

• In the Navigation TreeIn the Navigation Tree select the newly added LED

• On the Button Palette select Modifying > Editing > Copy

• Click in the 3D Design View to place the copy of


View to place the copy of the LED near the original

• Repeat the copy procedure to create a total of three LEDs

Multi-select the LEDs• In the Navigation Tree

<Ctrl>-click to select all three LEDs

• In the Tool Bar click the Info

Adding more than one entity to the Properties Dialog Box tree can be very helpful when editing

lti l bj t• In the Tool Bar click the Info button to open the Properties box with all three LEDs selected in the tree

multiple objectsEntities can be added to an existing Properties box by <Ctrl>-clicking on the entity in the Navigation Tree


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Set the LED Coordinates• In the Properties Dialog

Box Tree <Ctrl>-click to select all three LED groups

The values for all the selected entries are set at the same timeOnly works for identical property tabs

groups• On the Coordinates tab

enter:– X = -304.8– Y = 87.15– Alpha = -90

Right-clicking on a field will bring up a list of current values that can be selected


Set the Z Offset• In the Property Dialog Box Navigation Tree select each

LED group in turn and set the values to:– Z = -190

Z 0– Z = 0– Z = 190

• Click OK to save the changes and close the Property Dialog Box


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Check the LED Position• Select the Edit > Show

All menu item• Select the View >

Render Mode >Render Mode > Wireframe menu item

• On the Tool Bar select the UCSYZView button to orient the 3D Design View

• Verify that the LEDs have been placed properly


been placed properly• Save the model as Task

Lighting with LEDs.lts

Add a Receiver• In order to run a

simulation we need at least one source and a receiverSelect Vie >

Surface receivers are always attached to a surface or a dummy planeSurface receivers

• Select View > Render Mode > Translucent

• Select the center surface on the base, right-click for the pop up menu, and select Add

can calculate the following:

IlluminanceIntensityLuminance (optional)Color (optional)

Each type of calculated data is h


Receiver• Open the receiver

property box and set the units to Photometric

shown on a “Mesh” (a 2D grid) Units can be Photometric (default) or Radiometric

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Run Simulation• Use Ray Trace > Simulation Input

to set the number of rays to 100,000– Click Begin Forward Simulation

The simulation can run in the forward and backward directions. The gforward simulation is more common


Illuminance Output• Results tab for the

Illuminance Mesh shows a summary of the illuminance output

• Mesh Data tab providesMesh Data tab provides the row data for each bin on the mesh

• The X and Y axes on the raster chart are aligned with the X and Y coordinates of the surface

© Synopsys 2012 30 Introduction to LightTools, “Task Lighting”Analysis > Illuminance Display > Raster Chart

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Photoreal View• You can generate a

photorealistic view of the model to show its appearance (a picture of the model)

Photoreal settings are only applicable to the photoreal viewThe data you see for the regular forward/backward simulation is not ff t d b th tti• This can be a lit (LEDs turned

on) or unlit view of the model• We need to define the

“appearance” of each surface

affected by these settingsAll surface settings are defined on the Finish tab


Creating a Photoreal View• In 3D View, select Photoreal >

New Photoreal View– This will open a new photoreal

view with the default camera

Use CTRL+Right Mouse to rotate, align, and zoom the view (same as the 3D View)view with the default camera

anglethe 3D View)

Repaint View

Stop Rendering


Lit Render ON/OFF Run Lit

Simulation

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Selecting a Finish• Select Box_L, Box_R, and MWFrame

using CTRL+Left-Click in the System Navigator (use SHIFT+ Left-Click if you’re selecting in the 3D View)

Ri ht Cli k d l t Edit All

Model Finishes are the currently active finishesWhen you apply a Library Finish, it will move to the Model Finishes

• Right-Click and select Edit All Descendents > Surfaces

• On the Finish tab, select Library Finishes > Nature > Wood > Varnished > Varnished mahogany and double-click to add it to the model finishes, and press "Apply" to use it for the selected surfaces


Repeat Finish Selection• Select the BackWall and

Base, right-click and select Edit All Descendents > Surfaces

• On Finish tab, choose Library Finishes and navigate to Nature > Rocks and Minerals > Granite > Hornblende granite


• Double-click on Hornblende granite to add finish to the model, and press "Apply" to use it for the selected surfaces

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Apply Finish to Individual SurfacesYou only need to set the finishes of the surfaces that are visible in the desired view

Front Surface(Microwave )

Top Surface

• In 3D View, select an individual surface for a specific finish

• FrontSurface of Microwave – Crystal and Glass >

Refractive > Gray Glass• TopSurface of Base

p(Base )


• TopSurface of Base– Ceramics > Porcelain >

Porcelain– Color > Black

Photoreal View Settings• Set the background to

none (black)– View > View

Preferences…– Repaint the Photoreal

View– Select View > Contrast

> Equalizing

1

2


3

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Unlit Photoreal ViewPhotoreal View is sensitive to the display settings on your computerIn order to create the best rendering you must adjust therendering you must adjust the View > Contrast > Tone/Contrastsettings as appropriate


Tone/Contrast Settings

Lit Photoreal Simulation• Using PhotoReal > Lit

Simulation Input… set the Total Rays to Trace = 1 000 000

Lit Simulation collects data for photorealrendering on each surface. It will also update 1,000,000

• Click Begin Lit Simulationthe regular simulation data (such as charts). The regular simulation does not collect photoreal data

Typically you need a large number of rays in order to generate photoreal views


with high fidelity

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Lit Photoreal View• In the Photoreal View click

LitOn to turn the model sources on

By default the photoreal view is generated with some ambient light level in order to be able to see objectsYou need to balance the ambient and model lighting when you enable g g ylit renderingThere are Studio Lights you can add to your model for different lighting effects

Point Light


Point Light

Spot Light

Distant Light

Getting Help• There are multiple ways to access Help

• Help > Contents and Index (HTML)• Help > Document Library (PDF)

S h ll d t i th lib ith− Search across all documents in the library with

» or• What’s This?

− For command and Toolbar buttons, using HTML help• Dialog level help (HTML)


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Workshop 1: Flashlight• A simple flashlight model will be used as a sample

system for photorealistic rendering.

F tt d fl t 0 85° G iFacetted reflector; 0.85 Gaussian scatterer

Bulb with cylinder source3λ representation of a 3500K blackbody source

Window


WindowTarget: reflective Lambertian

scatterer

Workshop 1: Create Photoreal View• Open supplied file FlashlightPRR.1.lts• Open a Photoreal View (Photoreal > New Photoreal

View)Add b i h Vi P f f h• Add scenery by opening the View Preferences for the Photoreal window. On the Scenery tab, select either a Base or a Room and apply to model. Example: Tiled RoomUnlit appearance


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Workshop 1: Lit Rendering• Run a photoreal simulation of 100,000 rays

– Photoreal > Lit Simulation Input… to set the rays– Photoreal > Begin Lit Simulation

• View the lit target in the Photoreal window– Running the lit rendering disables the camera light; only the light from

the LightTools source is visible• Source spectrum is 3500K Tungsten

– Use Saturation to adjust color of output (View > Contrast > Tone/Contrast)


Saturation=1.0 Saturation=0.0

Workshop 1: Add Studio Light• Add a point light above the flashlight and update the

photoreal view– Photoreal > Place Point Light, on command line enter XYZ

0,600,600 Note: you don’t need to repeat the simulation to update the lit appearance


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Workshop 1: Change Surface Finish

• Currently, the surface finish on the flashlight body is the Default Mechanical Absorber.

• Select a different surface finish from the library and apply it to the surfaces of the flashlight body.


Workshop 1: Change Surface Finish (2)• Example:

– Select FlashlightBody, right click in 3D View and Edit All Selected > SurfacesCli k Fi i h t b l t Lib Fi i h M t l >– Click on Finish tab, select Library Finishes, Metals > Aluminum > Aluminum and double click to add to Model Finishes tab

– On Model Finishes tab, change color as desired– Repaint the photoreal

view to see the new finish


– In this case, you don’t need to repeat the simulation since only the studio lights interact with the body of the flashlight

Documents

Building and Simulating a Task Lighting Model in LightTools · Building and Simulating a TaskBuilding and Simulating a Task Lighting Model in LightTools ... Introduction to LightTools