Creating Sections and 2D Drawings in Rhino 8: ClippingSections Guide

The ClippingSections and ClippingDrawings commands in Rhino 8’s official help documentation can be used to create section views from a model and convert them into 2D drawings. This workflow is useful for architects and 3D users who want to inspect the inside of a design, create different section views, and prepare drawings linked to model geometry. The steps below are limited to the options described in the Rhino 8 documentation.

1. Create the section plane

1. Select the objects you want to section, then run the ClippingSections command. The documentation lists its menu location as Sections > Create.

2. Place the section plane in one or more viewports. If the widget turns red while placing it, it may not intersect the overall World-coordinate bounding box of suitable objects for the selected section.

3. To continue without selecting objects and section all objects, press Enter at the selection prompt.

4. Adjust the command-line options before placing the plane. Dir sets the section direction; Clip determines whether clipping is enabled in the view that was active when the command started. You can later change which viewports the section is active in through its properties.

The direction determines how the section passes through the model. CPlane creates a section parallel to the current construction plane. X and Y use directions perpendicular to that plane and parallel to the X or Y axis, respectively. Custom sets the direction based on a line defined by two points. Since the section line depends on the design decision, choosing the right direction is important for the readability of the resulting drawing.

2. Set the depth and view labels

CustomDepth determines whether the cutting depth is limited. When set to No, the cutting plane has infinite depth; when set to Yes, the Depth setting becomes available, allowing you to define the visible thickness of the sectioned portion. The documentation specifies a default depth of zero. A value of zero produces thin sections. A limited depth can help control the view when you don’t want geometry behind the plane to show.

You can set a name prefix with Name to make sections easier to find later. For example, entering SEC makes Rhino number the names sequentially as SEC_01, SEC_02. LabelMode controls how the name appears in the view: None turns off the label, Dot uses a dot label, and Text displays the name as text beside the direction indicators. The documentation lists Text as the default label mode.

SaveToNamedView creates a Named View associated with the section. However, if the section is placed in a perspective viewport, the resulting saved view will use perspective rather than parallel projection. If the projection type matters for the output, choose the placement viewport accordingly. Flip reverses the clipped and unclipped sides.

3. Convert the section into a 2D drawing

1. Start the ClippingDrawings command. The documentation lists its menu location as Sections > Create Drawings.

2. Select one or more clipping planes; you can use the All option for all visible planes. Then specify the points where you want to place the drawings. Enter places the base point of the current drawing at the World Top origin.

3. Adjust the output contents with the command options. ShowHatch controls whether hatches are generated from sections when the object’s section style is set to display them. ShowSolid determines whether planar surfaces are created from sections through solid objects.

4. AddBackground=Yes adds visible and hidden silhouette curves in front of the section plane to the drawing. AddHidden controls hidden background lines, while AddSilhouette controls silhouettes. Objects or layers excluded in the section properties are not added to the background drawing.

When adding a background, set Projection to Parallel or Perspective. For perspective views, you can set the camera target with SetTargetPoint. You can rotate the drawing with Angle and link line thickness to the layer or clipped object with PrintWidth. DisplayColor also sets the color based on the layer or input object. Enable ShowLabel if you need a label; LabelStyle selects a dot or text format. Use ApplyToAll to apply the same options to multiple drawings.

4. Updates and architectural workflows

Drawings linked to a clipping plane update interactively when the plane is moved. However, if the clipped objects or their properties change, run UpdateClippingDrawings to refresh the drawing. Drawings are organized into layers, which helps manage visibility in modeling and layout spaces. Deleting a clipping plane also deletes its associated drawing and layers. Using Explode on the drawing block breaks the link between the drawing objects and their source objects.

For architecture and interior design teams, this method makes it possible to create multiple sections from the same model and manage them alongside views. You can control which objects are included in a section during presentation or drawing production with the All, Include Selected, and Exclude Selected options under Objects Clipped; selection can be made by object or by layer. Before sharing a drawing, check the section direction, depth, labels, and background curves. If the geometry has changed, refresh the drawing as well; bear in mind that deleting the plane also removes its associated drawings and layers.

Common mistakes

• Treating a red section widget as merely a visual warning: the documentation associates this with the widget not intersecting the overall bounding box of suitable objects.

• Setting CustomDepth=Yes but overlooking the Depth value: the depth limit affects the thickness of the visible sectioned portion.

• Assuming the drawing will update automatically after source geometry or properties change: in this case, UpdateClippingDrawings is required.

• Failing to check linked outputs before deleting a clipping plane: its associated drawings and layers are also deleted.

These tools are based on the commands and options described in the Rhino 8 documentation. Menu names and workflows may differ in other versions, so check the help documentation for the relevant version when working in another release.