Solar Lighting in Ecotect.

1. New York City
College of Technology
The City University of New York
Lighting in Ecotect
Architectural technology department
written by Nicole Seekely
revised April 15, 2010 8:25 PM

2. Notes:
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Lighting in Ecotect
Step One:
Once your model has been
brought into Ecotect, click on
the Visualize tab located on
the very left side of the screen.
This will show your model
shaded based on materials
you have assigned.
The following are some useful
shortcuts:
Right Mouse Rotate
Ctrl + Right Mouse Pan
Shift + Right Mouse Zoom
F2 Repeat Last
F3 or Double Click Nodes On/Off
F4 Isolate Selected Zone
F5 Plan
F6 Side
F7 Front
F8 Axonometric
X,Y,or Z Nudge Object in Direction
Shift + X,Y, or Z Nudge Object in
Negative Direction
Insert Insert Child Object (Door,
Window, Void)
Ctrl Hold to Move Cursor in Z
direction instead of X,Y
N Snaps On/Off
A,C,G,I,L,M,O,P Snap Option
(Align, Centre, Grid, Intersections,
Lines, Midpoints,
Orthogonal, Points)
Ctrl + F Fit Grid to Model
Spacebar Toggle among selected
objects

3. Notes: If your location is not listed, there are ways of downloading additional weather
files off the internet or creating your own. There is ta tutorial located at S:ARCH-2450
Trudell that takes you through the process of creating your own weather file.
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Lighting in Ecotect
Step Two:
To get the correct lighting
analysis, you will need to
load the weather data for
your location. Click on the
Earth symbol, and select
Load Weather File. Select the
appropriate location and hit
Open.

4. Notes:
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Lighting in Ecotect
Step Three:
Hit F10 or Go to Display -
Shadows to allow the current
shadows for the time and day
to show.
You can set the time and day
at the top of the screen next
to where you set the weather
data.
You can also change the
shading effects of your sur-
faces by clicking on the
Visualization Settings tab to
the right. If you scroll down
the screen, you can adjust
settings such as Shade Sur-
faces.

5. Notes:
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Lighting in Ecotect
Step Four:
Also in the Shadow Settings
menu you can turn on/off the
daily and annual sun paths.
This will allow you to get and
idea about the orientation of
your building relative to the
sun angle.

6. Notes:
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Lighting in Ecotect
Step Five:
Also in the Shadow Settings
menu you can turn on the
shadow range. This will show
the shadows for the given day
during the hours you set.

7. Notes:
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Lighting in Ecotect
Incident Solar Radiation:
You can run solar analysis
on your building to see how
much incident solar radia-
tion hits each surface. There
are several different settings
you can use to show different
information. Try starting with
these and then experiment
with others:
Go to Calculate - Solar Ac-
cess Analysis
Leave all the default options
selected as you go through
the Wizard.
Click OK in the end and allow
time for the program to calcu-
late. The status is shown on
the bottom of the screen.

8. Notes: Make sure your normals are facing the correct way. The normal for each surface
should be facing outwards. To check this, go to Display - Surface Normals. If the normal
arrow is not in the correct direction, hit Ctrl+R to reverse its direction.
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Lighting in Ecotect
You should end up with all the
surfaces of your model col-
ored according to the amount
of incident solar radiation they
receive at the given time. You
can change the day and time,
and the model will automati-
cally update.
You can change display set-
tings and show more infor-
mation by going to Display
- Object Attribute Values.

9. Notes:
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Lighting in Ecotect
How To Show Light Levels
Across A Surface:
Step One:
Select the surface(s) you want
to run the analysis on. Click
on Modify - Surface Subdivi-
sion - Rectangular Tiles
Step Two:
Select your subdivision size.
The smaller the size, the more
detailed and accurate your
results will be but also the
l onger the run time will be.
You can adjust some settings
to better fit your surface.

10. Notes: With the many subdivisions, don’t be surprised if the calculation takes several min-
utes.
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Lighting in Ecotect
Step Three:
With the subdivided surface
selected, go to Calculate -
Solar Access Analysis.
Step Four:
Go through all the steps as
before. Incident Solar Ra-
diation, choose your Time
Period, Average or Cumula-
tive, Check that the values
are calculated for selected
objects only and clear values
from other objects. For shad-
ing mask, choose Detailed so
that you can adjust the set-
tings. For faster calculations,
choose Medium and Low.

11. Notes: You can also show Text Values and change other settings from the Object Attribute
Values menu.
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Lighting in Ecotect
Step Five:
You should end up with an
array of colors depicting the
level of radiation. You may
need to adjust the scale if
your surface is one color. Go
to Display - Object Attribute
Values - Custom Scale.
Step Six:
Change the value range until
you get the desired effect.

12. Notes: Make sure your normals are facing the correct way. The normal for each surface
should be facing outwards. To check this, go to Display - Surface Normals. If the normal
arrow is not in the correct direction, hit Ctrl+R to reverse its direction. You’ll know you’ve
done it right if your graph looks like this. If it is all gray (meaning completely in the shade
all day), it’s likely your normals are reversed.
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Lighting in Ecotect
You can also get more de-
tailed information about a
given surface. Click on the
surface (you can select ob-
jects in the 3D Editor tab, not
the Visualize tab). Then go to
the Analysis tab.
Here you have 4 different
options for Solar Exposure
Calculations.
Single Day - shows the amount
of hourly exposure on the
selected surface
Average Daily - amount of
radiation on surface on an
average day each month
Total Monthly - cumulative
values for each month
Full Hourly - same as total
monthly, which each day’s
results shown
Hit Calculate after making a
selection.

13. Notes:
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Lighting in Ecotect
Internal Lighting Calcs
It is possible to show the inte-
rior lighting conditions as well.
To do this, you’ll need to set
up an Analysis Grid.
Step one:
Click on the Analysis Grid Tab
to the right. The click on the
Grid Management button.
Usually the default settings
are okay to start with. Note
that here you can change the
number of cells to get more
precise information, but it will
take much longer to calculate.
Step two:
The Z height of the grid
should be set to something
around 600mm or 2’. You can
change this to however high
or low you want it to be, but
the default is the standard
height for interior lighting cal-
culations.

14. Notes: You will notice that the analysis grid doesn’t stretch over the whole floor. There is a
perimeter gap. This is correct - you don’t want the grid to touch the walls or it will produce
false information.
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Lighting in Ecotect
Step Three:
Select the floor and then hit
the button “Auto-Fit Grid to
Objects.” A menu will pop-
up. You want to fit “Within”
the “Selected Objects.” All
the defaults should be okay
to use.

15. Notes:
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Lighting in Ecotect
Step Four:
Go to Calculate - Lighting
Analysis
Step Five:
Select “Natural Light Levels”
and click Next. Keep it on the
Analysis Grid and click Next.
Adjust your ray-tracing to how
precise you want it and click
Next. The higher, the longer
the calculation time. Enter
your design sky illuminance
or allow Ecotect to calculate
it for you and click Next. Set
your Window Cleanliness and
click Next. Select Regula-
tory Compliance or Accuracy
Mode and click Next. Finally,
click OK if everything looks
good.

16. Notes:
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Lighting in Ecotect
Step Six:
You can adjust the display of
the analysis grid in the Grid
Settings menu. You can turn
on/off grid lines, contour lines,
etc. You can also show val-
ues in 3D.
You can also change the Con-
tours setting. Try changing
to .5 and you will get a much
more gradiated effect.

17. Notes:
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Lighting in Ecotect
Analysis in Radiance:
You can bring your Ecotect
model and information into
another program called
Radiance. This will allow for
further Lighting Design Calcu-
lations.
Step One:
You will need to set up a cam-
era that will be the view from
which information is shown in
Radiance. Click the Camera
button and choose to place
Interactively.
Step Two:
Place the camera wherever
you want an interior shot.
Use Ctrl to move the cursor
up in the Z direction. Click a
second time for the direction
of the camera.

18. Notes: To view through your camera, go to the Visualize tab and click on the Camera tab
at the bottom of the screen.
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Lighting in Ecotect
Step Three:
With your analysis grid
shown, you are ready to ex-
port. Go to the export tab on
the rightside menu. Click on
Export Model Data.
Step Four:
Select ILLUMINANCE to ren-
der the amount falling on the
surfaces. Click Next. Choose
Final Render and click Next.
Choose your sky and click
Next. Choose date and
time and click Next. Gener-
ate Interior views and select
your image size, click Next.
Make sure that you have your
camera selected in the menu.
Use Medium for your accura-
cies. And finally, select your
save location. Click OK.
You may be prompted to
locate the .exe file. This is
usually at C:RadianceBin
rad.exe

19. Notes: Navigate through the different images created by the tabs at the top.
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Lighting in Ecotect
Step Five:
Depending on how your set-
tings are, it may take awhile
for Radiance to render out
the image. You can see the
progress in the DOS prompt
window. Eventually a window
like this one should pop up.
You can then generate a
series of images with informa-
tion overlayed:
Make sure you’re on the first/
original image tab. Then
select one of the options
from the Information Overlay
menu. Set your scale to be
a maximum of 4000 instead
of the default 1000. You
can change the number of
divisions as well, but 10 is a
good start. Then click the
green arrow to generate a
new image.

20. Notes:
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Lighting in Ecotect
Step Six:
You can click on the image
itself to generate the Lux for
that particular point on the
surface. This allows for a
fairly precise analysis.
You can save your images
through the File menu.

21. Notes: To get the grid to show a gradient as seen, turn on your contours and off your grid-
lines in the Analysis Grid Settings Tab.
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Lighting in Ecotect
You can also import data
such as Illuminance from Ra-
diance back into Ecotect as
shown in this model.
Just make sure you select the
Surface and/or Point Analysis
option in the Wizard. This
will automatically import the
results back into the Ecotect
analysis grid once Radiance
is done.

22. Notes:
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Lighting in Ecotect
Ecotect and Radiance use
Lux as the default unit. To
change the values to Foot-
candles go to Grid Manage-
ment, Edit Grid Data tab
and type in V*0.093. This is
because every 1 Lux is about
10 Footcandles.