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 as needed.

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:

Organize model in SketchUp layers

Mandatory for: Daylight Factor, Watt
Optional for: Sun Exposure, 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:

  1. Switch to ‘Color by layer’: Window -> Default Tray - > Layers -> Color by layer
  2. Remove unused layers: Window -> Default Tray - > Layers -> Purge
  3. 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:

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:

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

How to activate extension

All extensions developed by De Luminae 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 geometry normally.
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 toggle_material_icon