Generic element Grasshopper Styles Tutorial

Comparison between the Grasshopper generic element on the left and the VisualARQ generic element on the right.

In this tutorial a parametric generic element style from a Grasshopper definition will be created. Generic elements or just elements are an extra category used for any kind of element that doesn’t fit in any of the other ones, like in this case a lighting fixture. The Furniture category follows the same principles as the generic elements, that’s why everything on this tutorial would be valid for a furniture style.

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

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

1. Grasshopper definition setup

You can download the complete Grasshopper file clicking here.

Type Grasshopper in the Rhino Command line to launch Grasshopper.

  1. Input parameters components:

    They are the values that will define the features of the resulting generic element style. In this case all of them are numeric (floating point) sliders that define all dimensions of the generic element, for example the cable length. The different kinds of inputs are:

    • Numeric value (floating point): A total of 6 sliders have been used for the various dimensions of the light.
  2. Output components:

    They are the “ending” components. They need to be Geometry Params that are no further connected to any other components. They will be read by VisualARQ as the different parts of the Element style. In this case there are three breps, one for the cable, one for the head and another for the bulb.

The complete Grasshopper definition is shown in the image below:

The generic element Grasshopper style definition. On the left the various input parameters and on the right the geometry components as output.

The Grasshopper definition that generates the generic element.

2. Create the VisualARQ generic element style

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

2.1: Create the new style

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

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

The element 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 generic element 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 Element Grasshopper Style Wizard. In this step the Grasshopper file is selected.

2.3: Configuration

Set the Element Grasshopper style global values:

  • Style name: set the desired name.
  • Definition units: in this case the Grasshopper definition was created in millimeters.
  • Insert point: the base point to place the element, any input Point parameter in the GH definition will be available here. If no point is chosen the origin of the GH definition will be used instead. In this case the light was build according to the origin of coordinates, that’s why no point is needed.
Second step of the Element Grasshopper Style Wizard. In this step the name, the units and the optional Insert Point from the Grasshopper file are selected.

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 geometry outputs that correspond to the Model representation. The Plan representation will be taken from the horizontal section of the 3D elements according to the level’s cut plane height.

Third step of the Generic Element 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 generic element 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: in this case this option will be selected so the parameters 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 the settings of different parameters at once by selecting them while holding the Ctrl key.

Fourth step of the Generic Element Grasshopper Style Wizard. In this step one of the settings is the "Editable by", which has a dropdown with three options (definition, style and object).

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 of them are floating point values that automatically have been set to Length.

3. Insert and edit a VisualARQ element created from the Grasshopper Element Style

3.1 Edit the element style

Once the Grasshopper style wizard is completed, the new style will appear in the element styles list with its corresponding subcomponents (Bulb, Head and Cable). 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 Generic Element styles dialog with the new generic element 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 element 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 element 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 a generic element with the new style. The input parameters appear in the Properties panel since they have been set as editable by object.