Annotation Grasshopper Styles Tutorial

Comparison between the Grasshopper annotation on the left and the VisualARQ annotation on the right.

In this tutorial a parametric annotation style from a Grasshopper definition will be created. Specifically this example is about the Elevation Mark style that comes with the VisualARQ templates.

The 3 main steps to follow are the same as in any other Grasshopper style:

  1. Grasshopper definition setup
  2. Create the VisualARQ annotation style
  3. Insert and edit a VisualARQ annotation created from a Grasshopper style

1. Grasshopper definition setup

You can download the complete Grasshopper file clicking here.


This Grasshopper definition uses VisualARQ Grasshopper Components so make sure VisualARQ is loaded before you open the .gh file.

Type Grasshopper in the Rhino Command line to launch Grasshopper.

  1. Input parameters components:

    The input parameters are the values that will define the features of the resulting annotation style. In this example we can find the following input types:

    • Plane: Specifies the base point (and plane) for the annotation.
    • Hatch Pattern: Specifies the hatch pattern for the annotation.
    • Number Slider (floating point): There are 4 of them and are used for the various dimensions of the annotation.
    • Number Slider (integer): Specifies the amount of decimal places.
  2. Output components:

    The output components are those that will be read by VisualARQ as the different parts of the annotation. In this example we can find 3 types of them:

    • Text
    • Geometry
    • Hatch

The complete Grasshopper definition is shown in the image below:

The Grasshopper definition that generates the annotation

The Grasshopper definition that generates the annotation

2. Create the VisualARQ annotation style

In this case the Grasshopper style will be created and managed from the Annotation Styles dialog.

2.1: Create the new style

Assuming the Grasshopper definition (.gh file) is already done, open the annotation styles dialog: _vaAnnotationStyles.

Click on the New… button and select the Grasshopper style option.

The annotation styles dialog with the "Grasshopper style" option visible after clicking on the "New..." button.

The Grasshopper Style wizard will appear. This wizard will guide you through the steps to define the annotation Grasshopper style parameters. The left side of the wizard will show a preview of the object style generated as soon as the required information is completed.

2.2: Open the Grasshopper definition

Click on the Browse button to select the .gh file created before.

First step of the Annotation Grasshopper Style Wizard. In this step the Grasshopper file is selected.

2.3: Configuration

Set the Annotation Grasshopper style global values:

  • Style name: Set the desired name.
  • Definition units: In this case the Grasshopper definition was created in meters.
  • Insert Plane: The base point to place the annotation. Any input Plane or Point parameter created in the GH definition will be available here.
    • If no point or plane input is chosen (“None” option), the origin of the GH definition will be used instead. But the elevation value will not be linked with the annotation’s location.
    • If there was a point input in the GH file (instead of a plane), and it was chosen here, the annotation would take the elevation of the point’s plane as a reference, but its orientation would be constrained to that point’s plane in the Grasshopper definition.
    • If the plane input is chosen, the annotation will be placed oriented to the current construction plane of the viewport where the object is inserted. This is the recommended option in this example.
Annotation GH Style Wizard 3

2.4: Geometry

Specify which of the geometry blocks to import into VisualARQ. The identifiers of these Geometry blocks are taken from the names of the output components in the Grasshopper definition and can be modified only once the style has been created.

Each component can be assigned to a different representation:

  • Model: the object representation in 3D.
  • Plan: the object representation in plan view. Only visible when the Cut Plane of the level where the object is placed is enabled and intersects the element.

In this case there are three outputs and all of them correspond to the Model representation. In the case of annotations rarely there is a plan representation because it corresponds to the model representation.

Third step of the Annotation Grasshopper Style Wizard. In this step the geometry to be displayed and its representation is chosen.

2.5: Parameters

This step shows the settings available for the list of input parameters that define the annotation style. The “Filter by” dropdown can be used to view individually each of the named groups of input parameters that were created in the Grasshopper file. The settings available for each of the inputs are:

Name: is the identifier of the parameter and can be modified if desired in this step.

Editable by:

  • Definition: the parameter will be hidden in the VisualARQ style and properties dialog.
  • Style: the parameter can be edited by style, so the changes will apply to all elements with that style.
  • Object: the parameter can be edited separately for each instance of that style in the model. In case no value is provided by object the one defined by style will be used. You can change several ones at the same time by selecting while holding the Ctrl key.
Fourth step of the Annotation Grasshopper Style Wizard. In this step four settings are available (Name, Editable by, Default value and Type).

Default (value): shows the default value for the parameters (the ones specified in the Grasshopper definition) and lets you set different default values.

Type: shows the different types of values available for each kind of parameter. In this case all have been automatically set to their corresponding type. Almost all of them are floating point values of type Length, but there is also one of type Integer and one of type Text.

3. Insert and edit a VisualARQ annotation created from the Grasshopper Annotation Style

3.1 Edit the annotation style

Once the Grasshopper style wizard is completed, the new style will appear in the annotation styles list with its corresponding subcomponents (Symbol, Text and Hatch). To edit the style again, right-click on the style name to open the context menu and select Edit. This operation will open the Grasshopper style wizard again. The parameters are available under the “Parameters” tab and appear grouped as in the Grasshopper definition. In case the name of the group matches an existing category they will appear combined.

The Annotation styles dialog with the new annotation style. When it is selected the parameters appear under the "Parameters" section grouped as in the Grasshopper definition.

3.2 Insert the Grasshopper style

Once the annotation style has been created, you will be able to insert an instance in the document. You will be able to change the values of its parameters from the VisualARQ annotation icon located under the Properties panel. Only those input parameters that were set as editable “by Object” in the step 2.5 will be visible.

Example of an annotation with the new style. None of the input parameters appear in the Properties panel because all have been set as editable by style.