Using 3D Molding Polylines

Reference Number: KB-02882
Last Modified: July 16, 2021

The information in this article applies to:

Chief Architect Premier or Chief Architect Interiors


What are 3D Molding Polylines and how can they be used?


The 3D Molding Polyline tool is much like the normal Molding Polyline tool but more flexible. A molding polyline must be drawn in plan view, so one advantage of 3D molding polylines is that you can draw them in elevation or section views and create vertical moldings. Another advantage of 3D molding polylines is that they do not have to be coplanar, meaning that a given edge can go in any direction in all three dimensions.

The following image illustrates three objects; each derived from a similar shape using a polyline solid (left), a molding polyline (center), and a 3D molding polyline (right):

Polyline Solid, Molding Polyline, and 3D Molding Polyline

In this article, an oblong mirror will be created, and a custom frame will be generated using a 3D molding polyline.

To create the mirror

  1. Navigate to 3D> Create Orthographic View> Cross Section/Elevation  from the menu, then click and drag towards the wall that will have the mirror.

  2. Select Build> Primitive> Polyline Solid , then click and drag to create a rectangular polyline solid.

    2' by 4' polyline solid created in a section view

    In this example the polyline solid is 2' by 4' in size.

  3. Using the Select Objects  tool, click on the polyline solid to select it, then click the Open Object edit tool.

  4. In the Polyline Solid Specification dialog that displays next:

    Set the Thickness on the General panel of the Polyline Solid Specification dialog

    • On the General panel, set the Thickness to 1/4".

    • On the Materials panel, select the Polyline Solid component and click the Select Material button. Browse to or search for a "Mirror" material, select it, then click OK.

    • Click OK again to close the dialog and confirm the changes. 

  5. With the polyline solid still selected, click on the upper edge to make this the active edge.

    The edge of a polyline based object that has the largest edit handle is the active side. All other sides will have smaller edit handles.

  6. Select the Change Line/Arc edit tool to convert the upper edge to an arc.

  7. Click the Make Arc Tangent edit tool. In the Radius of Tangent Arc dialog that appears, click OK.

    Radius of Tangent Arc dialog

  8. Repeat steps 6-7 for the lower edge

    Mirror with arcs that are tangent to the sides

To create the frame using a 3D molding polyline

  1. Using the Select Objects  tool, select the polyline solid, then navigate to Edit> Copy and Paste in Place .

  2. With the new, copied polyline solid selected, click Convert to Plain Polyline edit tool.

  3. Next, click the Convert Polyline edit tool.

  4. In the Convert Polyline dialog that displays, choose the 3D Molding Polyline option and click OK.

    Select the 3D Molding Polyline option in the Convert Polyline dialog

    Note: 3D molding polylines can also be created by navigating to Build> Trim> 3D Molding Polyline, then clicking and dragging in your desired view. 

  5. In the 3D Molding Polyline Specification dialog which opens next, click on the Moldings panel.

    Adjust the molding profile on the Moldings panel of the 3D Molding Polyline Specification dialog

    • Notice that a square molding profile is already chosen. Click Replace and browse to a more appropriate molding.

      In this example, the CA-24 chair rail profile is used.

    • Set the Width and Height of the molding to be the thickness and depth of the frame desired for the mirror.

      In this example, the Width is set to 5/8" and the Height is set to 3".

    • Specify any other properties such as the profile's rotation and offset.

      The ability to reflect a molding profile is not available in X12 and prior versions.

  6. Select the Materials panel to choose an appropriate material for the molding profile, then click OK to close the dialog and confirm the changes.

  7. Take a Camera view to see the results.

    Perspective Full Camera view looking at the mirror

Consider blocking the polyline solid and the 3D molding polyline together so the mirror is treated as a single entity. To learn more, please see the "Creating an Architectural Block" resource in the Related Articles section below.