This tutorial will walk you through the basic workflow from setting up your Rhino model to using the Full Floor Plate Daylight Feature using the Rhino/Grasshopper plugin v.2.0.2 or later.
Before you Begin:
A. Download the latest version of the Rhino/Grasshopper Plugin
This feature requires the latest version of the SketchUp Plugin (v.2.0.2 or later) from the Food4Rhino.com or cove.tool Plugins Page. This update contains additional export categories, different from the previous plugins, such as interior walls and shading devices. To install the plugin, just open the plugin as a regular grasshopper script, no additional steps are necessary. Screenshot of the script are below.
B. Create a new project in cove.tool
Before starting the export process, create a project in cove.tool online. If you have not started a project, then the Rhino/GH Plugin will not have a project location to reference for your geometry export. Start a project, complete the project-details page, and get to the Geometry Page. Once you have your geometry page open, you will have a project to link to in step 2 of the grasshopper script.
Start your export. Inside Rhino (v.5 or later)...
1. Unhide, Unlock, and relocate your Rhino project near the Origin Point
Open your project. Make sure all your building geometry is un-hidden and unlocked, by typing "Unhide" and "Unlock" in the command bar. Many process will happen in this file, so if you prefer work on a copy of the primary Central model. Next, make sure your model is located near the Rhino origin axis (coordinates: 0,0,0). By placing your geometry here, it will ensure your building will accurately display once inside cove.tool.
2. Set Units to Feet
The grasshopper script requires geometry to be in Feet to display accurately in cove.tool. If your project is set to SI: Meters, that will remain the case after the daylight page. To change units, type "units" in the command bar. The "Document Properties" window will open, select "Feet" in the "Model units" dropdown list. Click yes when prompted to scale your model. Check the project scale by measuring a known length of your building.
3. Move all geometry to appropriately named layers
The plugin process can be expedited if you have the correct building geometry filter into correctly labeled layer that house each cove.tool export category. Categories include Floors, Roofs, Windows, Exterior Walls, Interior Walls, Skylights, and Shading Devices. Makes sure all the objects have been sent to their correct category. Misplaced object can be normally swapped between layers, so make sure this is done before exporting your geometry to cove.tool. Misplaced objects are the #1 cause of inaccuracy in the plugin.
4. Explode, Un-group, and delete all non single-surface objects in your file
The grasshopper plugin will only accept single single-surface objects. To check if you geometry is single-single surface, highlight your project and type explode. This command may need to be repeated until objects cannot be simplified further. The geometry categories below will need to be simplified with the following checks.
- Grouped Geometry - Select blocks with command "SelGroup" and type "ungroup" and "explode" in the command bar until geometry has been simplified.
- Blocks - Select blocks with command "SelBlockInstance" and type "explode" in the command bar until geometry has been simplified. Also open the "BlockManager" and delete all contents to eliminate all block geometry
- Curves (Lines) - Select curves in project with command "SelCrv" and delete, line geometry is undesired
- Polysurfaces - Select blocks with command "SelPolySrf" and type "explode" in the command bar until geometry has been simplified.
Note: If you modeled your building geometry with thickness and have six-surface polygons, that may cause severe model clean-up. Re-massing the project may be a faster resolution.
5. Purge File of Bad Geometry
Bad Geometry is the number one cause of crashing grasshopper scripts. Luckily in Rhino, there are three helpful commands to eliminate bad geometry.
- Purge (_Purge) - "Purge" command will search the entire Rhino File for unused and problematic model elements. Click enter twice to eliminate all purge-uncovered objects.
- Select Duplicates (SelDup) - This command will find all identical objects which occupy the same 3D Space as a existing object. Delete all duplicated objects.
- Select Bad Objects (SelBadObjects) - Bad objects are objects in Rhino which were brought over from a different platform and are struggling to display correctly and thus will not be able to export accurately with the Grasshopper Plugin. Solution is to rebuild these objects. One recommended method to remake a bad object is listed below.
- Select one bad object at a time. Trace the bad object with command "Silhouette". While the traced curves are highlighted, type command "join" to join all curves which will convert them to closed-curves. Convert the closed curve into a single surface with command "Patch". A window will pop up, in Surface U spans and V spans change the "10" value to a "1", then click ok. Delete the bad object and lines, and you should now have a compatible single-surface object. If the object had openings, i.e. window punches, then the command "Silhouette" will have generate multiple closed curves. Select only the most outer profile line of the object then type command "Patch" to convert it to a single-surface object. Then select the reminder of the trace outlines and then type command "trim" and click the area at the center of the outlines to trim the surface and create surface openings.
6. Check for flipped-face geometry
The cove.tool grasshopper plugin uses a property-tag front-face/ back-face of each plane to determine the cardinal orientation of each surface. For Example: a surface's area will be filtered into the category of the direction that its front-face is facing (for reference, this is the same tag/property is used to apply materials on surface). If area categories look incorrect, check your project for inverse-facing surfaces.
- To check, use the back-face settings in "Properties>Rhino Options>View>Display Mode>Shaded - Backface Settings" to set a 'single color for all the backfaces' (see image below). Surfaces facing the wrong direction [outwards] will appear in the backface color.
- To correct orientation, surfaces can be flipped in Rhino with the command "Flip" (second image).
It is crucial to have all building envelop geometry displaying front facing surfaces outwards, and all horizontal plane geometry have their front planes facing upwards. This step ensures all of your building components are imported with accurate cardinal directions, i.e. that your building geometry falls into the correct orientation (N, NE, E, SE, S, SW, W, NW). Once everything is correctly oriented, you are ready to export your building geometry.
Project is now ready for Grasshopper
7. Launch Grasshopper
Use the command “Grasshopper” to launch the grasshopper plug-in. Rhino 6 comes with a version of grasshopper already installed, so no additional steps are necessary. If you are using Rhino 5, make sure you have installed GhPython and Grasshopper for Rhino 5.0 (64-bit), to continue with the plugin process. Version previous to v.5.0 are not compatible with the cove.tool plugin.
8. Find and Open the covetool.gh
Locate the file you downloaded from Food4Rhino. Make sure the contents have been unzipped and saved in a familiar location, before using. Select the .gh file inside to launch the grasshopper script. The most recent version of the plugin published is titled "covetool_daylight_energy_v2.0.2" or higher. Once the script load, users should see the image at the top of this article.
9. Login to cove.tool
Step 1 of the Grasshopper script is logging in with the user's cove.tool account' Username and Password. If the login credentials do not match your cove.tool credentials, the export process cannot begin. Once logged-in, the project list in step 2 will automatically populate and display the user's project list.
10. Use the number slider to Select a Project
Step 2 of the script is selecting a project from your project list using the number slider. Manually enter, or use the slider to select the number which identifies your project in the project list. The project list will only list project which have been created before entering the username&password. If a users has not passed the 'Project Details' page to the geometry page, then cove.tool and the plugin will not officially consider the project created.
- After selecting a project, its time to select geometry and export to cove.tool. Before beginning this process, right-click the grasshopper plane and select “LockSolver” so to not be slowed down by the computing process every time you import new data, by not using the LockSolver your grasshopper can freeze, crash, or take longer than usual to compute and update.
11. Export your Building Geometry
To begin exporting geometry, users will use the Breps (Boundary representation) and set multiple surfaces for each of the following categories: [Required] “roof surfaces, floor surfaces, opaque wall surfaces, and window surfaces, [Optional] skylight surfaces, interior wall surfaces, and shading devices. Each export is unique and the following will explore tips and challenges for each category. Once all Breps are completed and lines connected, disable the LockSolver and jump to the cove.tool web app to see your results. (NOTE: Before you begin, there are required and optional geometry export categories. Required export categories, require some amount of surface area in the Brep in order to successful export and initiate the Daylight simulation. If your project does not have geometry in this category, then creating a miniature plane with dimensions smaller can 1"x1", would be an acceptable work-around method. A geometry export this small should not impact the energy model aspects of your project, and placement would not matter for final results.)
- Bundling Height (Required) - Export building height by right-clicking the building height Brep and selecting the “Set one Line” prompt. Jumping back to your Rhino model, begin a line from the lowest point of your model and continue vertically-locked to the highest point in your model. The measurement will be automatically recorded into the geometry page once the “LockSolver” has been disabled. Also note the building height export should be the lowest point to highest point of conditioned space, for more information see here.
- Roof Surfaces (Required)- Right-click on the Brep and depending on the amount of roof objects in your model either select the "Set Single Surface" prompt or the “Set Multiple Surface” prompt. Jumping back to the Rhino Model, select the single surface objects that best illustrate the combined surface area your projects roof(s) surface area. This includes all exterior envelope building elements that are exterior and enclose conditioned spaces from above. (Note: Do not include cantilevers as they have no energy impact on a building.) Once selected, click the enter key, and the grasshopper script will automatically recognize the geometry to complete the export.
- Floor Surfaces (Required) - Repeat the same steps as roof surfaces export, but for floor surfaces which best illustrate the combined floor(s) surface area of your entire project. Be wary of selecting multiple surfaces on the same plane, as they may double-log surface areas and will result in double-counting square-footage calculations and incorrect energy results. Also make sure to not export the roof object as a floor, that would result in a bright red surface area and thus an inaccurate sDA%.
- Skylight Surfaces - Again, repeat the same steps in roof surfaces for skylight surfaces with a Skylights Brep. Not all projects have skylights, so if your project does not include geometry for this category, then leave this section empty.
- Shading Device Surfaces - Again, repeat the same steps in roof surfaces for Shading devices surfaces. Not all projects have shading devices, so if your project does not include geometry for this category, then leave this section empty. As a general reminder, Shading Devices are elements with are not part of the thermal envelope of the building but do provide an amount of solar obstruction, this includes overhangs, fins, cantilevers, frit, trees, context buildings, spandrels, and more.
- Interior Wall Surfaces - Repeat the same steps in roof surfaces for interior walls surfaces with a new Brep. Not all projects have interior walls, so leave this category empty if you have yet to model interior walls. For reference, interior walls are opaque planes inside the thermal envelope which provide solar obstruction. Interior glazing, door, and furniture are not required for this export and may slow the simulation considerably.
- Opaque [Exterior] Wall Surfaces (Required) - Repeat the same steps in roof surfaces for opaque exterior wall surfaces. Because cove.tool is an early stage energy modeling software the only data we need from your building geometry are the areas in which Heat Transfer occurs. If you have a project that has Fins or Overhangs, those should be exported in the shading device layer. Only exterior objects which enclose the projects thermal envelope.
- Window Surfaces (Required) - Repeat the same steps in roof surfaces for window surfaces with a new Brep. Similar to Opaque wall surfaces, the window surface selection only pertains to areas on the exterior face of the project. Interior glazing should not be imported to cove.tool at all. Also, mullions, exterior doors, and spandrels would be included in the window selection process and not in the wall surface category.
12. Disable LockSolver and Check for Export Success
Once you have completed selecting geometry for all applicable export categories, right-click the grasshopper plane and disable the “lockSolver” to unfreeze the simulation. "Step 5 - Daylight Uploaded" will display the text success when the geometry has officially exported to cove.tool. The display of an error text will indicate the simulation has failed at some point in the run. Locate a panel with might be orange or red to see where the error could have occurred and repeat the export for that category. Make sure no non-single-surface geometry is found in the selection.
13. Refresh Geometry page and go to cove.tool
Once you have achieved a "Success" in the grasshopper script, navigate to the cove.tool geometry page in a web browser. Here you will refresh the page and see the building data promptly displayed. If you notice some of the information does not look accurate, flip back to Grasshopper and double-check your model’s measurements. Likely there might be a object that is mis-layered and has added up to a calculation in the wrong category. Once everything looks good, click the Daylight Icon in the left-hand Navigation Bar (sun icon) to save the geometry export and move to the 3D Visulization Page. Your model should take anywhere from 30 seconds to 10 minutes to load in the 3D Mode space. The Export Process is complete.
NOTE: If you were not able to successfully export your model to cove.tool, please check out the Troubleshooting Grasshopper article here.