Rhino to Revit - Modelical (2024)

Rhino to Revit Interoperability

Objectives

Get the geometry we want properly modelled within Revit.

Prerequisites

1. First thing we should think about before doing a Workflow between Rhinoceros and Revit, is how will we need the geometry modelled in Rhinoceros.
2. Of course, it is necessary to have an adequate mastery of both tools.
3. User is a nice person

Description

Rhinoceros and Revit are programs with different properties. While Rhinoceros is a good option for modelling complex surfaces and geometries with precision, Revit is a high quality program for modelling with information. So working with both programs in a properly way can easily implement and optimize our work. Most times we will use Revit as the main platform of work and just will need Rhinoceros to model complex geometry (mostly surfaces) that would be really hard to do in Revit.

Will we need to measure areas and volumes in Revit? Are we going to create families in Revit and we will just need to quantify the amount of families in the model? Are we going to use the geometry just as a reference in Revit?

Curves And Surfaces Best Practices

Once you proceed to work with curves and surfaces in Rhinoceros , if geometry is imported from other software , the first thing you should do is to check that the geometry is correct:

To find out whether a curve (control points curve, arc, etc.) is well imported into Rhinoceros, we have to check their control points. To do this, first of all select the curve to analyze and then press F10.

• A correct curve will have just the minimum number of control points to define the curve accurately.
  
• An excessive number of control points can lead to precision errors and problems when working with this geometry in Revit.

If the curve is incorrect , you must redraw or rebuild the curve using the "Rebuild" command, paying attention to the deviation from the original curve.

To find out whether a surface is well imported into Rhinoceros, we have to check their isocurves. By default, in Rhinoceros you directly preview the Isocurves of any surface.

A correct surface will have just the minimum number of isocurves to have an accurate definition.

An excessive number of control points can lead to precision errors and problems when working with this geometry in Revit.

Normal surfaces direction

Rhinoceros surfaces have distinguishing faces, that is, each surface have a front face and a back face. This is called directionality of the surface.

It is important that all surfaces have a normal direction in the same orientation; since different operations carried out in Rhinoceros and Grasshopper may vary depending on the orientation of the surface. If we have a closed volume, the normal direction of the surfaces will be oriented outward.

To preview the direction of the surfaces press the “Dir” command. If it is required to change the direction of the surface, just press the “Flip” command.

Another option to preview the direction of a surface is to change the Rhinoceros´s options of displaying geometry activating the color of backfaces.

Accuracy in the vertex´s joints

When working with adjacent surfaces it will be checked the coincidence between edges and vertices of both surfaces.

To sum up with the best-practices working in Rhinoceros we have to consider whether the size of the file is ok or not. In this case, we will consider the use of Worksessions.

A work session or a sharing file allows multiple users to work on a large project at the same time. The source project is divided into several files that can be edited independently; each file can only be edited by a user, however the rest of the team can view it but not modify it.

Exporting Surfaces

Before exporting any surface from Rhinoceros to Revit we must know which type of surface it is. It is highly recommended to optimize the surfaces before exporting to Revit; depending on it the results will be right or not.

Surfaces in Rhinoceros are classified by the following parameters:

• Surface degree
• Topology
• Curvature
• Trimmed or untrimmed

Surfaces in Rhinoceros are classified by the following types:

• Open Surface
• Open Extrusion
• Open Polysurface
• Closed Polysurface

To analyze the surface, we will use the “What” command and we will preview the Control Points pressing “F10”.

• Not acceptable surfaces for export are those with an excessive number of control points, collapsed surfaces or those whose control points do not correspond with their axes surfaces, often trim surfaces.

Types of Surfaces

Export file analysis

Type of Surface / Use in Revit:

Workflows

Workflow A. Direct import

Steps:

1. Insert >> Import CAD.
2. Select the positioning option.
3. Select units.
4. Deselect “Correct lines that are slightly off axis”.
5. Select type of file DWG (*dwg) or ACIS SAT (*.sat).
6. Open.

Characteristics:

This type of workflow will be chosen when there is no need to work later with the geometry.

It is appropriate only if this imported geometry will not be represented in views such as sections and elevations, because when directly imported, CAD geometry is not correctly cut by cut planes in views.

It cannot either be converted to native Revit elements.

Workflow B. Import in Mass

Steps:

1. Massing & Site >> In-Place Mass.
2. Insert >> Import CAD.
3. Select positioning option.
4. Select units.
5. Deselect “Correct lines that are slightly off axis”.
6. Select type of file DWG (*dwg) or ACIS SAT (*.sat).
7. Finish Mass.
8. Mass Tools >> By Face modeling (ceilings, floors , walls and curtain systems)

Characteristics:

When the imported geometry will be represented in views (plan views, sections, elevations) it is advisable to import geometry into a mass, otherwise it will not be properly cut by view cut planes.

This type of workflow will be chosen also when it is needed to create native Revit elements such as walls, roofs and floors based on the imported surfaces, using “By Face” tools.

Workflow C. Family import

Steps:

1. Open chosen family template (depending on the future category).
2. Insert >> Import CAD.
3. Select positioning option.
4. Select units.
5. Deselect “Correct lines that are slightly off axis”.
6. Select type of file DWG (*dwg) or ACIS SAT (*.sat).
7. Open.
8. Modify visualization properties >> Imported Categories >> Object´s style >> Imported Objects >> Imported Layers.
9. Rename´s categories names.
10. Modify material.
11. Repeat that process to all the layers/materials imported.

Characteristics:

This procedure will be used when the geometry is needed to create complex families in Revit.

Workflow D. Rhynamo

Steps:

1. Open Revit project
2. Open Dynamo >> Rhynamo package
3. Select Rhino´s file path
4. Follow

Characteristics:

This method is the best one if we need to create complex geometries in Revit. Thorough this via we can directly import geometry to Revit skipping the process of exporting it from Rhinoceros and afterwards importing it in Revit.

However, we have some problems when reading the geometry in Rhynamo. Just is able to read Surfaces, having problems with other types of geometries such as Points, Curves and Polysurfaces.

Workflow E. Plain Data, Flux or Speckle

Steps:

1. Manage geometry/data in Grasshopper
2. Export data to CSV/XLS or use Flux/Speckle
3. Open Revit project
4. Open Dynamo >> Collect data with Flux/Speckle
5. Manage geometry/data in Dynamo
6. Bake to Revit

Characteristics:

This method is very powerful to get pure native Revit elements in a bulk way. It’s necessary to manage the information as simple as possible, for example, text, points, curves, and combine those elements with Revit elements, like families or adaptive components.

Workflow F. IFC with Visual ARQ

Steps:

1. Rhinoceros:

• Model in Rhinoceros using Visual ARQ Objects: Walls, Curtain Walls, Structure, Doors, Windows, Stairs, Railings and Roofs.
• Model in Grasshopper using Visual ARQ - Grasshopper plugin.
• Export to IFC

2. Revit:

• Link IFC
• IFC Options: Metric Template

Characteristics:

This is an option to use Rhinoceros as a BIM software. However, it is far more limited than Revit.

Tips&Tricks

Working in Rhinoceros before importing:

1. Choose model units and precision according to the project.

• Usually for large scale architectonic projects it will work in meters and an accuracy of 0,0001.
• For smaller scale projects where a high definition is required, it will work in millimeters with an accuracy of 0,01.

2. Work near the origin (0,0,0)
3. It is recommended to unclick “Smart Track” tool from the Working Modes Toolbar, located (at the bottom of the canvas). This tool helps to work using drawing references, as it creates temporal references of dots and lines that are drawn in the active view in Rhinoceros. This option could bevery useful when working in simple 2D drawings. However, when working in 3D models, this tool often leads to mistakes. Furthermore, in the tool “Osnap” from the Working Modes Toolbar it is recommended to unclick the option “Near”.
4. Define a hierarchy of layers , grouping the layers according to the most optimal approach depending on the type of work that is going to be done. This will enable collaboration between several professionals in complex file.

• If we are going to use Grasshopper in Rhinoceros, it is recommended to have a layer for the inputs for Grasshopper and a layer (or several ones) for the exported geometry.

Conclusion

We have several options to import the geometry:

A. Direct import of the Rhino geometry (sat or dwg formats) into Revit. This option is a valid one for volume references in Revit, using the imported geometry without material properties.

B. Import the Rhino geometry (sat or dwg formats) into a Mass in Revit. This is the best option to convert the geometry imported into native elements in Revit (floors, walls, ceilings and curtain walls).

C. Import the Rhino geometry (sat or dwg formats) into a Family in Revit. This is an option to model complex geometry families in Revit.

D. Import the Rhino geometry into Dynamo through Rhynamo.

E. Import the Rhino geometry / data into Dynamo through Flux.

F. Export the Rhino geometry to IFC.