The world of lighting design has been disjointed since the advent of BIM in that lighting calculation software usually requires remodeling of building elements and importing Autodesk® Revit® elements is usually more work that remodeling. Then last year, Lighting Analysts crafted the first fully-integrated lighting add-in for Revit called ElumTools. This application brings lighting analysis into the BIM process and integrates it with building designer’s software of choice, Revit. This article discusses ElumTools capability and workflow.
Once ElumTools is installed, an ElumTools tab is added to the Revit ribbon. The tools are arranged left to right to follow a typical workflow. The Settings tool accesses the calculation parameters, file system setup and other miscellaneous items. Web-based support is available from the Help Info tool.
The Luminaire Manager tool opens a dialog that controls parameters of lighting fixture families found in the model. Light fixture families must have a photometric source and an associated IES file for an accurate lighting simulation. Families in the model without a photometric source and an associated IES file will be shown with a Red “X” indicating there is an issue.
The IES data appears in the definition tab, it even includes a total light loss factor calculator. Other tabs allow the user to adjust the source size and position, its display, and to classify as an emergency fixture. A tab of this dialog also shows a photometric web or polar curves view of the selected fixture. This interface allows the user to tweak the lighting without editing each individual family. This is immensely time saving and fits a process of iterations very well.
The Material Mapping tool links to the materials in the model. It sorts the materials in use from those merely present in the model. Each materials link can be set to None, Unidirectional, or Bidirectional. This is indicated by a red vertical bar, a two-headed arrow and a single-headed arrow, respectively. When materials are altered in this dialog, the link is automatically set to the vertical red bar, breaking the link. The user can then decide to make it a bidirectional link and push the changes back into the Revit model. This allows the user to use the ElumTools interface to drive the materials or let Revit round trip the materials individually. It is important to ensure the material parameters are accurate to get the desired results.
The Current Revit (API) does not provide access to materials “Render Appearance” information.
Once the luminaire settings and material settings are complete, the Calculation Points tool is used to assign planes for the calculations. Calculations Points do not have to be placed to get surface exitance and visualizations, but they must be added for point-by-point calculations. Under the Add Points tool the Room and Space workplane tools can be used to add points based on Revit room and space objects. The workplane height of the points is adjustable after initial placement. To place points on a vertical or raised surface, use the Planar Face tool. Unfortunately, the points do not display at this time because they do not yet have a value associated with them.
Calculation and Visualization by Room or Space is done much the same as placing calculations points. After the area selection is made, the Calculation and Visualization window opens and the radiosity calculation process begins. When complete, the calculation points can be viewed in luminance visualization, mesh, and pseudocolor.
The images can be adjusted while open. The viewer can be closed as desired, but must be re-rendered to view again.
The View/Update Results tool displays the calculated points inside of Revit. The Hide Results tool, well, hides the points.
Statistics are shown when the room/space object is selected in the Properties dialog. To see average values by space or room, a schedule should be created using Revit’s built in scheduling tools. ElumTools data is added to the model as shared parameters. Since calculation points can be placed three ways—by room, space, or plane—the parameters are actually different. This means that trickery will have to be used in order to schedule combinations of room, space, and planar data into a single schedule. Consider the final output when creating the calculation planes.
Benefits and “Gotchas”
Things to know about how ElumTools when working with linked models.
- The light fixtures used, the rooms or spaces referenced, and the calculation points must reside in the host model. Lights sources in linked models will not function along with linked room/space objects.
- Materials in linked models need to be mapped using the material mapping tool. It is a good idea to spend time up front setting the standard Revit materials as required, or creating a set of standard materials for quick use ahead of time.
- ElumTools likes each model to contain a 3D view in which all the needed geometry is visible. This aids in its ability to find the geometry.
- ElumTools will have difficulty with the Calculate Selected Elements tool if any of the selected elements are in a linked file, because Revit does not want to individually select linked objects.
- ElumTools cannot tap the phase mapping of linked models and may produce unexpected results when the host and linked files are using different phases.
- Surfaces that do not have a material assigned to them are ignored by ElumTools with the exception of luminaire surfaces. Luminaire surfaces are automatically assigned the default material. Users can use the Revit Paint tool to apply materials as required.
Because ElumTools adds data in the form of parameters into the host Revit model, room/space tags can now include handy information such as luminance minimum, average, and maximum values by adding those parameters to the required tags.
Color fill legends can also be created that can show items such as average illuminance by room. This view can be used to quickly identify trouble spots that are over- or under-lit with a quick glance of what color is currently filling a given room.
When it comes to lighting fixture families, it is not uncommon for firms to build their own generic content as well as use manufacturer-supplied content. In either case, be aware of how ElumTools deals with the modeled geometry of the lighting fixture obstructing or redirecting light from the light source. If the light source and the modeled components of the light fixture are created in the same family, ElumTools ignores the modeled geometry as far as obstruction, deflection, and reflection is concerned. When light source families are nested into a parent file, ElumTools will show obstruction, deflection, and reflection. Nested light source families need to be “shared” or ElumTools will not recognize them in the project.
ElumTools is brought to you Lighting Analysts, the same fine folks that make AGi32. That knowledge should give users a lot of confidence in the underlying engine and the capability of the software. In fact there are many other functions and options like Luminaire switching and dimming, luminaire luminous area, an emergency mode setting for emergency fixtures, controls for tweaking the mesh material and color bleed in radiosity, and capability for self-luminous surfaces.
ElumTools is a welcome addition to a market short on third-party tools and applications for Autodesk® Revit MEP®. If a BIM workflow is the goal, applications such as ElumTools are required for reuse of data and to “pay it forward” to future consumers of the model. The interface is surprisingly straightforward for a complex tool. ElumTools harnesses the Revit platform and leverages every last bit of its functionality. The learning curve is not steep for a confident lighting designer, but a solid understanding of Revit is also required to work this solution. That might be the hard part in the short term, but in the long term, Revit wins, and so does ElumTools.