Lightscape Tutorial 1: Introduction Last Modified: 1999 02 06

This tutorial provides an introduction to the interface and some of the basic features of Lightscape. It addresses the analysis of daylight in a space. In subsequent tutorials, electric lighting features will be introduced.

The EVDS lab has 15 copies of Lightscape.  Most of them are installed in the lab with the 350MHz Pentiums (the lab with the plotter).


Part I -Export a Form-z Geometric Model for Use in Lightscape

Lightscape was created for analysis of lighting of spaces for which the geometry has already been created in another program.

From EVDA 655, you will be familiar with creating geometry models in Form-z.  

The beginning point for learning Lightscape will be importing a geometry model from Form-z. The model is called "tut1.fmz" and may be found on a network drive as follows:  1) You must first log in to Hal, the EVDS server.  2) One of the drives (in this case a "virtual" drive")  now available to you is Courses on Hal  3) On this drive (double-click it), you will find folders including Jim_Love_Courses  4) In Jim_Love_Courses, you will find a folder 617 that holds files for  EVDA 617.


1. Create a directory for your tutorial work. The directory may be in your share of drive "x" or on a zip disk.  NEVER keep your data files on a single device (e.g., floppy, zip disk, or server area).  ALWAYS back up your work, at least on a daily basis.
2. Copy the file "tut1.fmz" to the directory just created.
3. Launch Form-z and open the file "tut1fmz.fmz" - it is a simple office space. Note that the "glass" in each window is a 2D entity (has no depth); this is critical in terms of modeling the glass property in Lightscape.

The model has an upper "daylighting aperture," which contributes the most to illumination further from the window wall. This reduces the geometric fall-off in illumination with increasing distance from the window, which in turn helps to reduce glare. The tilted ceiling is a solution that allows a higher window head in buildings with service zones above the ceiling.

The lower "view aperture" has the primary function of providing a view, although it is the greatest contributor to illumination adjacent to the window.

Note that there are no exterior or interior shades to control sunlight, the most serious source of glare associated with daylighting.

4. Select "File-Save As" to save a copy of "tut1fmz.fmz" to your tutorial 1 directory.

Set File Format to 3DStudio File Format is the last item in the dialogue

When you click Save, a "3DS Export Options" box appears

for "Grouping Method" select "Single Group" (the default). Click OK.



Part II -Import the Form-z Geometric Model for Use in Lightscape

Launch Lightscape. Note that an extensive on-line help facility is available (last menu item on the right). Note that allowing the cursor to linger on an icon will result in its name popping up in a "balloon."

1. Invoke "File-Import-3D Studio . . ."

"File Units" should be set to "Meters"

Scale Factor to "0.01"

"Block Creation" at "None"

"Layer Creation" at "Mesh"

"Maximum Light" at "2500"

An "Import 3D Studio" dialogue box appears.

2. Use "Browse" to locate the ".3ds" file you exported from Form-z.

Select "open" once you have located and selected the file.

If the model is at the right size (3.3 x 4.3 x 4 Meters), click "yes"

If the model is not at the right size(scaled incorrectly), click "no," adjust the scale factor and repeat until OK.

A Lightscape caution statement appears

A wire-frame display of the model will appear (see below). NOTE that the wireframe model will appear quite different from the Form-z wireframe, because the 3DStudio format breaks all polygons into triangles.

3. Invoke "File-Save" to give your new Lightscape file an appropriate name and save it in your tutorial directory.



Part III - Prepare Material Definitions and Assignments

The "tut1" file in Lightscape format is available in folder 617 within folder Jim_Love_Courses at network drive Courses on Hal should you have difficulty transferring the Form-z file to Lightscape.


Note the four palettes that appear to the right of the viewport - "Layers," Materials," "Blocks" and "Luminaires"

In the "Luminaires" palette (bottom right), "light_1" appears. This is a general light inherited from Form-z; all light sources in these tutorials should be specified within Lightscape, so it should be deleted . Left-click on "light_1" to select it and right-click in the "Luminaires" palette to call up the related menu. In the "luminaires" select delete. The "Luminaires" palette should now be clear of light sources.

Note that each Form-z entity has been assigned to a layer (make them invisible or visible by double-clicking on the red arrows to the left of each entry in the "Layers" palette).


You will now create a new material (drywall).

1. Place the cursor over the "Materials" palette and RIGHT click (click on the right mouse button) to call up the menu for the "Materials" palette.

Select "Create" in the menu.

The convention for WINDOWS is that RIGHT-clicking calls up menus on a "context-sensitive" basis (the menu that will appear will vary depending on the area of the display on which the cursor is placed).  LEFT-clicking is used to make selections.

A new material will be created identified by "Itemxx" where "xx" is a number.

2. LEFT click on "Itemxx" to select it if it is not already selected Selected elements are highlighted
3. RIGHT click to call up the "Materials" palette menu

select "Edit Properties..."

For "Material Name," replace "Itemxx" with "Drywall1"

A "Materials" palette menu will appear.  Note the "Rename" function in the menu.

a "Material Properties for Itemxx" dialogue box will appear

4. Under tab "Physics", click on the downward arrow to the right of the"Templates" heading

Scroll down to "Paint Flat" and release to select it

Click OK in the "Material Properties" dialogue box in which you are working.

Click "No" to "rename the existing material" as the dialogue says.

This finalizes creation of the new material called "Drywall1"

5. Repeat the above steps to create a material called "Glass70" (for glass with 70 percent transmittance).

Set the "Template" to glass and then move the slider opposite "Transparency" to set transparency to 0.70.

More correctly, "transparency" is referred to as transmittance - the fraction of visible light that will pass through the glazing.  This term will be discussed further in class.

You will now assign "Drywall1" to the surfaces in the office example (this material will be used for all surfaces, for the sake of simplicity).

1. Double-click entries in the "Layers" palette until only the solid office envelope is displayed (i.e., make sure that the two rectangles for window glass are turned off - these should be "Object6" and "Object7")
2. Invoke "Edit-Selection-Surface" Note that selection will affect surfaces, blocks, or luminaires [light fixtures] depending on the setting you choose.
3. Invoke "Edit-Selection-Select All" The surfaces of the office should all be highlighted (coloured red).

Note: If you ever have difficulty using "Select," make sure that the "Select" arrow (see below) is highlighted.

4. RIGHT-click in the viewport

LEFT-click to select "Assign Material..."

Click on "Drywall1" to select it and then click OK once "Drywall1" is highlighted"

A command menu appears in response to the "context-sensitive" operation.

The first command in the menu is "Assign Material..."

An "Assign Material" dialogue box appears.

5. Click on "Query Select" with the cursor and then click on any surface of the office (other than a window).

You will now check your material assignment.

In the second row of the toolbar, the first tool from the left is an arrow ("Select"); the next tool, the arrow with the question mark is "Query Select".

The surface will be highlighted and a summary of the properties will appear across the bottom (this should include "Material=Drywall1")

You will now assign "Glass70" to the glass surfaces in the office example (this will be used for all surfaces, for the sake of simplicity).

1. Double-click entries in the "Layers" palette until only the two rectangles for window glass are turned on
2. Invoke "Edit-Selection-Select All" The window glass rectangles should be highlighted.

The icon shown below also invokes the select all function.

3. Now you will invoke the "Assign Material" command.

Right-click in the viewport.

The first command in the list is "Assign Material..."

4. Left-click on "Assign Material"

Click on "Glass70" to select it and then click OK once "Glass70" is highlighted"

An "Assign Material" dialogue box appears.

Because these elements are transparent, there is an additional step; they should be assigned a special light-processing characteristic that makes the transparency active.

5. Right-click in the viewport

Left-click on "Surface Processing  Control"

Click in the check box beside "Occluding" to de-activate it.

Click in the check box beside "Window" to activate it.

Click "Apply" and then OK.

The third command in the menu that appears is "Surface Processing Control..." (see step 4 in the previous table for an image of this menu).

A "Surface Processing" dialogue box appears.

6. Use the "layers" palette to make all parts of the model visible.



Part IV - Prepare the Daylight Availability Conditions

Daylight  availability is affected by geographic position, time and date, and sky condition. You will now set these parameters.

1. Invoke "Light-Daylight..."

A "Daylight Setup" dialogue box will appear. There are "tabs" to select "Sun and Sky," "Processing," "Place", and "Time" options.

2. Under "Processing," all options should be selected (checked) except "Ray Trace Direct Illumination"
3. Under "Sun and Sky," leave "Sky conditions" at "Clear" (0.00) and the sky and sun colours at the default.
4. Under "Place," use the scroll list to select Calgary. Leave "North" at "0" (but note that this feature allows you to experiment with rotation of the building on the site
5. Under "Time," pick

month 6,        

day 21,        

1000 (morning).

Click "Apply" and then OK.

This is a good point to save your file, and then save it under a new name for experimentation with simulations.

IMPORTANT: Save the "preparation file" (preparation files have a ".lp" extension) for future use; once processing is initiated, Lightscape converts preparation files to "solution files" (".ls" extension). Surface properties and other features cannot be altered in solution files, nor can solution files be converted back to preparation files.


Part V - Run a Simulation - Interior Only

1. Invoke "Process-Parameters..."

Leave settings at defaults, except the following parameters in the "Process" area of the dialogue box (lower left of dialogue box):

Select "Daylight (sunlight + sky light").

Make sure that "Daylight through windows and openings only" is selected.

A "Process Parameters" dialogue box appears.

2. Click on "Wizard"

Leave "Quality" at 3

A "Quality" dialogue box appears.

There is a tradeoff between quality and processing time.

3. Click "Next"

Select "yes" for "Do you want to consider daylighting in your solution?"

Leave the FIRST of the three lower statements selected.

Click "Next," "Finish" and "OK," exiting the "Wizard" dialogue box.

A "Daylight" dialogue box appears.

You haven't set up any other source of light!

4. Invoke "Process-Initiate The next step will initiate the simulation.

When the simulation begins, the iteration number (the number of the light transfer being considered) will be shown in the lower dialogue bar of the viewport, along with the percent of the light energy distributed.

It will take about a minute to go through 30 iterations and distribute about 20 percent of the light energy. At around this point, invoke "Process-Stop," so you can view the results.

5. Invoke "Process-Go" The simulation will begin.  Let it run for another 30 seconds or so.

6. As noted in step 4, invoke "Process-Stop"

Invoke "Display-Solid" (or click on the corresponding icon in the last cluster on the right - use the help balloons to find it)

You may have to wait a few seconds for  completion of the iteration in progress.

Note that you may continue the simulation by invoking "Process-Go"

You will now see the illuminated interior of the space through the window. The outdoor surfaces are black, because the simulation was specified as an interior study.

7. Invoke "Display-Outlined" (or click on the corresponding icon in the last cluster on the right - use the help balloons to find it). You will now see the variable mesh used to calculate the light transfers. Lightscape uses these variable meshes ("adaptive gridding"), rather than a constant grid,  to improve on the usual tradeoff between accuracy and speed.




Part V - Run a Simulation - Interior and Exterior

1. Invoke "Process-Reset" This will reset the light distribution to 0, so you can begin a new study.
2. Invoke "Process-Parameters..." The "Process Parameters" dialogue box will appear.
3. Leave settings at defaults, except the following parameters in the "Process" area of the dialogue box.:

Select "Daylight (sunlight + sky light").

Make sure that "Daylight through windows and openings only" is selected.

This ensures that light enters the space only through intended apertures (e. g., it doesn't leak through inadvertently created cracks between walls),

4. Click on "Wizard"

Leave "Quality" at 3.

A "Quality" dialogue box appears.
5. Click "Next"

Select "yes" for "Do you want to consider daylighting in your solution?"

Select the  THIRD of the three lower statements selected.

Click "Next," "Finish" and "OK," exiting the "Wizard" dialogue box.

A "Daylight" dialogue box appears.

6. Invoke "Process-Go" The simulation will begin. It will take about a minute to go through 30 iterations and distribute about 99 percent of the light energy. At around this point, invoke "Process-Stop," so you can view the results.
7. Invoke "Process-Stop"

Invoke "Display-Solid."

The screen will appear entirely black, because outdoor light levels are so high that you must now adjust the "brightness" balance (more accurately, the luminance balance, as brightness is the subjective property).

8. Invoke "Edit-Properties"

If not selected, select the "Display" tab.

Set "Brightness" to about 90 to 100 (by clicking on "apply", you may evaluate the changes in scale).

A "Document Properties" dialogue box appears.

The interior AND exterior surfaces of the office are now visible.

It was necessary to adjust the display properties of the office  model in order to view it properly!



Part VI - Run a Simulation - Tools for Viewing

Tools for control of view type are located in the upper toolbar (fourth cluster from the left). You have been working in perspective view. Try the front view and then revert to perspective.

You can always return to the original view by invoking "Display-Original" - you can see the whole model by selecting "View-Extents" (in the cluster of icons second from right in the top toolbar).

It is also useful to be able to move around the space. The "motion" tools are located in the fifth cluster from the left.

1. "Orbit" allows you to rotate the model.

Select the tool (see figure).

In the viewport, click and drag up or down or from side to side.

2. "Rotate" allows you to rotate the model about your viewing position.

Click and drag up or down or from side to side.

3. "Zoom" allows you to move the view closer or further away.

Click and drag up for larger or down for smaller.

The fourth tool is "zoom window" - a tool you will have used in other CAD programs

4. "Pan" allows you to move the view from side to side or up and down.

Click and drag up or down or from side to side.

5. "Dolly" allows you to move in or out.

Click and drag up for in or down for out.

Try moving "inside" the office.

6. "Scroll" moves the view relative to the viewport.

Click and drag up or down or from side to side.

7. "Tilt" creates the effect of tilting your head.

Click and drag.


Congratulations, you have now completed the first Lightscape tutorial!