How to prepare SketchUp model for DL-Light calculation
DL-Light provides tools for calculation of physically based daylight indicators for your SketchUp
model. To get valid and accurate results with DL-Light SketchUp model should be
prepared in appropriate way:
Create and use a copy of SU file
It is always good practice to work on a copy of your original model, since you may need it
in future for some other calculations or presentations. Make a copy of model and
do all DL-Light related actions in this copy.
If you want to explore few alternatives of the same model, make multiple copies
Simplify and clean model
DL-Light calculations are based on validated ray-tracing software Radiance. They calculate
daylight indicators in sensors on your selected surfaces. If your model is complex
with thousands of surfaces, export and calculation will take longer, even for simple
indicators like SE or SVF.
Some cleaning steps you can use:
- Remove or set to invisible all geometry that doesn't have effect on indicator you
are calculating. Depending on extension and model you can remove:
Distant buildings - if you are calculating data for a single building
Furniture and interior geometry - if you are calculating any indicator only on external building
surfaces (eg. SE or SVF)
Minimize ground plane surface. Overall model size has effect on calculation time. Since ground
plane is usually the biggest surface in the model, make it as small as possible.
Remove collinear points. Collinear points exist when an edge is composed of more than one line.
This can cause wrong export, and import of FC materials. To clean model use
one of next tools:
Fredo tools: Remove Lonely Vertices
will show all problematic vertices in the model, and remove them or user request.
CleanUp: Repare split edges will remove problematic vertices, but
without any user interaction.
Manual model cleaning is required for some surfaces if automatic
cleaning didn't solve the problem. For problematic surface(s), find
edges that are composed of more than one part. Delete edge lines and
draw a single line instead (put line Layer to be the same as face layer).
Organize model in SketchUp layers
Sky View Factor
Every face in SU model can have layer and material defined.
Materials in SU are used for representation purposes, but are not suitable for
physically based calculations.
Layers are much better option, since all faces with the same layer can be treated
as they have the same physical characteristics. Eg put in one layer objects that
would be made of glass, in another objects made of aluminum, then wood etc. Number
of layers user can define is unlimited.
DL-Light only exports SU geometry by layers.
To organize your model in layers we recommend next procedure:
Switch to ‘Color by layer’:
Window -> Default Tray - > Layers -> Color by layer
Remove unused layers:
Window -> Default Tray - > Layers -> Purge
Create layers for various real-world materials and then attach them to appropriate objects.
Note that in SU it is possible to have a group/component in one layer and nested
faces in different layers. Only layers
attached to faces are taken into account
Some of methods you can use for layers attachment:
To check if surfaces in your model have correct layer:
Double-click to open each group
Select all its surfaces
Set layer for selected surfaces
Open DL-Light ‘Select by Layer’ dialog
In the dialog Select layers one by one.
For each layer check if correct surfaces are selected in the model
Create virtual surfaces
Detailed info when and why are virtual surfaces necessary for calculations is given on page
Create copy surfaces or virtual planes.
Two cases when virtual surfaces are necessary:
Calculation for surfaces inside group/component entities
SketchUp entities that are nested inside groups and components, are in
fact saved in model only once and then instanced over the model. Since
each of these surfaces is not unique, DL-Light cannot attach to it unique
id and perform calculation. As a result, after calculation on faces from
groups/components, the same false color results are imported on multiple
faces in model.
Solution for this problem is to avoid calculating surfaces which are inside
components and use instead virtual surfaces.
Calculation on workplanes
Some Daylighting labels, require calculation on a workplane that is offset
from floor surface. This surface is virtual, and consists only of sensors
for indicator 'measurement'. Creation of virtual surface provides location
for sensors and won't interfere with existing building geometry.
Adjust surfaces orientation
To be able to calculate any daylight indicator, it is necessary for light to fall on surface.
Faces orientation is important, since front side of the surface is receiving the
light. Recommendations below are only for surfaces which are used for calculation
External surfaces (eg. facades, roof, glazing) should be oriented towards
outside of the building. They are usually used for SE, SVF and Watt calculations.
Internal surfaces (eg, walls, floors, ceiling) should be oriented towards
inside of the building. Usually used for DF and DA calculations.
Horizontal virtual surfaces (eg. workplanes) should be oriented towards
up. Usually used for DF and DA calculations.
Other virtual surfaces (eg. for components entities) should be oriented
depending on indicator and position inside/outside of the space.
How to activate extension
All extensions developed by
can be used in the same SketchUp model, with restriction that single one can be active at each
time moment. This approach is used to avoid mixing and confusion of results for
various daylight indicators.
When SketchUp is started all De Luminae extensions are inactive and user can work on model
Mouse click on menu command or toolbar button to activate an extension. If another
extension is already in use, a confirmation is required.
When extension selection is confirmed, user interface and all results for previously
active extension are hidden, and interface and results for selected extension are
shown. The results for deactivated extension aren't deleted, and they can be used
again when extension is reactivated.
When new model is created or existing model opened, none of extensions' results are visible
until user activates an extension.
De Luminae extensions can be deactivated at any moment with click on toolbar button