In brief
- ShrinkWrap accepts NURBS surfaces, SubD objects, meshes, point clouds and point objects as inputs.
- Target Edge Length sets an approximate length for the output mesh edges; the default value is calculated automatically.
- Offset moves the mesh outward or inward relative to the source geometry and can also affect the face count.
- Rhino’s Mesh command creates a separate, editable mesh from a NURBS surface, polysurface or SubD.
What you’ll learn in this guide
In this guide, you’ll learn how to use Rhino 8’s ShrinkWrap command to create a mesh around different types of geometry and assess the key options that affect the result. ShrinkWrap can be used to create a mesh around multiple objects, work with 3D scan data, convert point clouds to meshes or handle geometry that is difficult to repair. McNeel’s documentation also lists creating closed meshes as a possible use; however, it does not guarantee a closed result for every combination of inputs and settings.
It’s also important not to confuse ShrinkWrap with Rhino’s Mesh command. The Mesh command creates a separate, editable mesh from specific object types, while ShrinkWrap creates a mesh around supported input types. The right method depends on the source geometry and the intended output.
Requirements
This workflow is based on the ShrinkWrap and Mesh commands described in McNeel’s Rhino 8 help documentation. ShrinkWrap accepts NURBS surfaces, SubD objects, meshes, point clouds or point objects. The documented inputs for the Mesh command are NURBS surfaces, polysurfaces and SubD objects. Since the source documentation does not specify particular hardware requirements, account types or licensing conditions, no additional requirements should be assumed.
Since mesh creation can affect inputs, consider whether you need to preserve the source objects before you start. ShrinkWrap has a Delete input objects option that can remove input objects if the output is successfully created. Check this option if you might need the source geometry later.
Creating a mesh with ShrinkWrap
Select the input geometry. Choose the objects you want the mesh to surround. You can use multiple objects in a single operation. If the inputs are a point cloud or point objects, pay particular attention to Inflate Vertices and Points; this option is enabled by default for point and point cloud inputs.
Use the preview. Preview lets you see the mesh that will be generated during the command session. Draw mesh wires displays the wireframe lines of the preview mesh. Hide input objects hides the input objects while you inspect the preview. Check the shape, face distribution and whether important details are preserved. Comparing different values in the preview helps you see how each setting affects the result.
Assess the Target Edge Length. This option sets an approximate target for the length of the output mesh edges. The default length is calculated automatically. Check how the value relates to mesh density in the preview; this setting alone does not specify an exact face or polygon count. Also keep in mind that increasing Polygon Optimization can cause output edge lengths to deviate further from this target.
Set Offset according to the desired output. Offset determines how far the mesh is displaced in model units. A positive value expands the mesh outward and adds more faces; a negative value pulls the mesh inward and reduces the face count. This setting has less effect on Target Edge Length. Check how the outer boundary changes in the preview, and don’t treat offset as another way to set edge length.
Check the smoothing effect. Smoothing iterations controls the smoothing strength of the output mesh. A value of zero disables smoothing. Higher values can reduce the number of faces and pull the mesh further inward. So face count alone is not enough: also check that the outer shape and key details suit the intended use.
Apply polygon reduction carefully. Polygon Optimization can be set from 0–100% and adaptively reduces vertices in the output. Faces on sharp edges are preserved as the face count decreases. Since higher values can increase deviations from the target edge length, assess this setting alongside Target Edge Length. A low polygon count may be desirable, but the model’s silhouette and details should also be checked.
Understand how point and vertex inputs behave. Inflate Vertices and Points uses every vertex or point in the input mesh or point cloud to create the output. If the input is a NURBS surface or SubD, vertices from the object’s render mesh are used; customizing the render mesh to add more vertices may be helpful. Parts created with this setting can merge into larger meshes when they intersect. A negative Offset moves the output closer to the source vertices or points.
Review hole filling and color options. Fill holes in input objects closes holes in the input objects before the mesh is created. This can be useful in many cases, but it may also close small openings that are intentionally left in the design, so inspect the result. This option has no effect on point or point cloud inputs when Inflate Vertices and Points is enabled. Compute vertex colors can transfer mesh vertex colors and point cloud display colors to the ShrinkWrap mesh.
Check whether input objects will be deleted. Delete input objects deletes the input objects once the output is successfully created. Check the option’s state if you need to preserve the source geometry. Finally, review the preview and settings before creating the mesh.
Common mistakes
Assuming every ShrinkWrap output is closed: McNeel lists closed meshes as a possible use, but that does not guarantee a closed result in every case. Before using the output, check that it meets the required specifications.
Using Offset to control mesh density: Offset changes the position of the output relative to the source geometry. For edge length, assess Target Edge Length; for face reduction, consider Polygon Optimization. Changing the settings one at a time and comparing the preview makes their effects easier to distinguish.
Overlooking how smoothing and hole filling affect the shape: High Smoothing iterations values can reduce the face count while pulling the mesh inward. Fill holes in input objects can close small gaps that are intentionally left open. In both cases, assess the result against the intended use of the model.
Treating Mesh and ShrinkWrap as the same operation: The Mesh command creates an editable mesh, separate from the source object, from a NURBS surface, polysurface or SubD. According to Rhino’s documentation, a mesh created from a solid can be watertight, which can be useful when exporting for rapid prototyping formats such as STL. ShrinkWrap, by contrast, creates a mesh around different input types.
Next steps in architectural and visualization workflows
In architecture and interior design projects, ShrinkWrap can be used to assess scan fragments, create meshes around multiple objects or prepare meshes for 3D printing. Visualization teams can try Polygon Optimization and Smoothing iterations when they want to reduce the face count. But a lower face count does not always mean a more suitable output; details, the outer boundary and the intended use should all be considered.
If the mesh will be exported to another file format or used in a manufacturing process, check separately that the output is suitable for that use. Don’t assume ShrinkWrap will always create a closed mesh. Rhino’s Mesh command, on the other hand, is associated in the documentation with producing a watertight mesh when created from a solid. Choosing the right command for the task can help reduce unexpected geometry issues in later stages.
Source and license
This guide has been adapted into English based on McNeel’s Rhino 8 ShrinkWrap and Mesh help documentation. Both sources are provided as license=free.
Sources
2 sourcesSource texts are not republished; short quotes are marked, everything else is our own summary and commentary.
For architecture firms and visualization teams in Turkey, ShrinkWrap’s value lies in its ability to create a surrounding mesh from different geometry types and work with scan data. It can be useful before 3D printing or transferring a model to another stage, but you should verify separately that the output is closed and suitable for its intended use.
The sources provide no specific requirements or licensing information concerning cost or hardware. So rather than making assumptions for a purchasing decision, it’s more sensible to compare the settings on a small sample within your existing Rhino 8 workflow. In particular, don’t overlook how polygon reduction and smoothing affect the form.
Frequently asked questions
What types of geometry does Rhino 8 ShrinkWrap support?
NURBS surfaces, SubD objects, meshes, point clouds and point objects can be used as inputs.
Does Rhino ShrinkWrap always create a closed mesh?
McNeel lists creating closed meshes as one use for ShrinkWrap, but does not guarantee a closed result for every input.
What does Offset do in ShrinkWrap?
Offset moves the output outward or inward relative to the source geometry. A positive value can produce more faces, while a negative value can produce fewer.
