In brief
- ShrinkWrap can create meshes that enclose NURBS surfaces, SubDs, meshes, point clouds, and point objects.
- Target Edge Length is calculated automatically by default. As Polygon Optimization increases, the face count decreases, while edge lengths may deviate further from the target.
- Fill holes in input objects fills holes in input objects before creating the mesh; it can also close intentional micro-gaps.
- Rhino 8’s Mesh command creates an editable mesh from a NURBS surface, polysurface, or SubD, separate from the source object.
In McNeel’s official Rhino 8 documentation, the ShrinkWrap command creates a mesh around selected NURBS surfaces, SubDs, meshes, point clouds, and point objects. It can be used to combine 3D scan fragments, prepare meshes for 3D printing, and create valid closed meshes from difficult-to-repair geometry. The steps below are based on the options described in the Rhino 8 documentation; no single setting should be expected to produce the same result for every model.
1. Decide what you need ShrinkWrap for
ShrinkWrap creates a new mesh around the selected inputs. McNeel lists uses such as creating a unified solid mesh from multiple objects, consolidating 3D scan data, and preparing meshes for 3D printing. Creating a valid closed mesh from damaged or difficult-to-repair geometry is another documented use, but this does not guarantee a closed output for every model and setting.
Select the geometry you want the mesh to enclose. The command supports NURBS surfaces, SubDs, meshes, point clouds, and point objects.
Run ShrinkWrap from the command session. The tool path documented by McNeel is
Mesh Tools › Mesh › Shrink Wrap.Inspect the output using the preview option.
Draw mesh wirescan display the preview mesh’s wires, whileHide input objectshides the inputs during the preview.Before using
Delete input objects, check whether you need to keep the input objects. This option can delete them if the output mesh is created successfully.
A mesh used for display is not the same as a mesh created with ShrinkWrap. Rhino’s Mesh command also creates a new, editable mesh from a NURBS surface, polysurface, or SubD; this mesh is separate from the source object. Don’t treat the two commands’ functions and settings as interchangeable.
2. Assess the effects on mesh density and shape
Target Edge Length sets the approximate length of the edges in the output mesh. ShrinkWrap calculates this value automatically by default. According to the documentation, increasing Polygon Optimization can reduce the number of faces further, but edge lengths may deviate further from the target. These options should therefore be considered together.
| Setting | Recommended value | Effect |
|---|---|---|
| Target Edge Length | Calculated automatically by default | Sets the approximate length of the edges in the output mesh. |
| Offset | The required distance, in model units | A positive value inflates the mesh and increases the face count; a negative value shrinks the mesh and reduces the face count. |
| Smoothing iterations | 0: smoothing off | Higher values increase the smoothing effect; they can also reduce the face count further and cause the mesh to shrink more. |
| Polygon Optimization | 0–100 in the documentation | Higher values reduce more faces; sharp edges are preserved, and edge lengths may deviate further from the target. |
| Fill holes in input objects | Enable if needed | Fills holes in input objects before creating the mesh; it can also close intentional micro-gaps. |
The values in the table are not a universal recipe for quality; they summarize the documented range and effects of the options. For example, increasing Polygon Optimization to reduce the face count can also make the mesh less faithful to the Target Edge Length value. Pay attention to the direction of the Offset: positive and negative values affect the mesh in opposite ways. McNeel notes that the offset distance has a more limited effect on the target edge length.
3. Check the options for point cloud and scan inputs
Inflate Vertices and Points creates the output mesh from the vertices or points of the input mesh or point cloud. For NURBS surface or SubD inputs, it uses the vertices of the render mesh. McNeel notes that customizing the render mesh for these inputs can help provide more vertices.
For point or point cloud inputs, check
Inflate Vertices and Points. This option is on by default for these input types and off by default for other object types.If you need more sample points from a NURBS surface or SubD, consider customizing the render mesh.
If you need to close holes in input objects, check the
Fill holes in input objectsoption. This option has no effect on point and point cloud inputs, or whenInflate Vertices and Pointsis on.Inspect the preview mesh. Keep in mind that meshes formed by intersections between multiple input objects can merge into larger meshes.
The hole-filling option can be useful in many cases, but the result should be checked because it can also close intentional micro-gaps. Similarly, although ShrinkWrap is listed as a way to create closed meshes, that does not mean the output will automatically be closed for every combination of geometry and settings.
4. Consider the Mesh command when creating editable meshes from NURBS
If you need a separate, editable mesh from a NURBS surface, polysurface, or SubD, Rhino’s Mesh command is another option. The default value for Density in its simple controls is 0,5; the accepted range is 0 to 1. As the value increases, the mesh’s polygon count goes up. Don’t treat this control as the same setting as ShrinkWrap’s target edge length.
In the detailed NURBS mesh settings, lowering Maximum distance, edge to surface makes the mesh more accurate, slower, and higher in polygon count. With Refine mesh off, the process can be faster, with a less accurate result and a lower polygon count. If Jagged seams is enabled, mesh edges on joined surfaces are not stitched; this can create gaps. According to the documentation, a watertight mesh is created when this option is off.
Common mistakes
Increasing
Polygon Optimizationwithout accounting for the fact that edge lengths may deviate further from the target.Assuming positive and negative
Offsetvalues affect the mesh in the same direction.Forgetting that filling holes can also close intentional micro-gaps.
Overlooking that the default state of
Inflate Vertices and Pointsvaries by input type.Confusing the
Densitysetting in theMeshcommand with ShrinkWrap options.Not checking the effect of
Jagged seamson mesh edges between joined surfaces.
Impact on architecture and visualization workflows
ShrinkWrap is a tool architecture and visualization teams can consider when working with scan data, preparing meshes from difficult-to-repair geometry, or attempting to create closed meshes for 3D printing. Tasks such as combining scanned fragments in interior design projects may also align with its documented uses. Check the mesh’s level of detail, face count, and hole closure separately against the intended use.
The Rhino 8 documentation does not specify hardware requirements or licensing conditions for this command. It is therefore not possible to recommend a particular graphics card, system specification, or license type. Before adding it to an office workflow, use the preview, review the option to delete input objects, and verify that the resulting mesh is closed as expected.
Sources
2 sourcesSource texts are not republished; short quotes are marked, everything else is our own summary and commentary.
For architecture and visualization offices in Turkey, ShrinkWrap’s practical value lies in bringing scan fragments, point clouds, and difficult-to-repair geometry into a mesh workflow. It can be tried when a closed mesh is needed before 3D printing or geometry transfer, but the command should not be assumed to guarantee this result for every model.
It’s important to assess settings according to the intended use: reducing the face count can affect adherence to the target edge length, and hole filling can close unwanted gaps. Since the documentation does not specify hardware or licensing requirements, offices should check their own Rhino installations for both. It’s also advisable to use the option to delete source objects with care.
Frequently asked questions
What geometry types does Rhino 8 ShrinkWrap support?
It can use NURBS surfaces, SubDs, meshes, point clouds, and point objects as inputs.
What does Polygon Optimization do in ShrinkWrap?
As the value increases, more faces are removed from the mesh and sharp edges are preserved. Edge lengths may deviate further from the target.
Can Rhino ShrinkWrap close holes?
`Fill holes in input objects` fills holes in input objects before creating the mesh. This option can also close intentional micro-gaps.
