Rhino 8 Patch Command: A Guide to Creating Surfaces from Curves and Points

McNeel’s official Rhino 8 help documentation describes the Patch command as a tool for creating surfaces from curves, meshes, point objects, and point clouds. This workflow guide, current as of 3 November 2026, walks through the command’s inputs and key options in the Surface Creation tool group. Rather than copying input geometry exactly, Patch calculates a surface from selected and sampled points. For that reason, check the boundaries and shape before completing the operation.

1. Define the inputs and the purpose of the surface

1. Start the Patch command from Surface Creation › Patch. Select the points, curves, or edges the surface will be based on. The command also accepts meshes and point clouds as inputs.

2. If you are using curves to create a closed shape that defines the outer boundary, select the curves in order. Each new curve must touch one of the curves already selected. This arrangement matters when you want to create a trimmed patch.

3. If the surface needs a change in form, such as a dip or bulge in the middle, add other curves that will influence its shape. These guide curves do not have to be connected to one another.

Do not assume that Patch will pass exactly through every selected curve. Rhino’s documentation notes that the resulting surface may not coincide exactly with all input curves. Select inputs that describe the overall form you want, then inspect the result in the preview.

2. Adjust sampling and surface shape

1. Use Sample point spacing to control the physical distance between samples along a curve. The documentation does not recommend a single ideal spacing, but states that each curve has at least eight sample points. This is the stated minimum for sampling, not a recommended setting.

2. Surface U spans and Surface V spans set the number of spans in the U and V directions of the automatically generated surface. The same values are also used when the starting surface is a 1×1-span plane. Since the documentation does not recommend a specific number of spans, there is no single value that works for every model.

3. The Stiffness setting controls how much the best-fit plane used in the Patch calculation can deform. Increasing the value reduces how much the surface can flex to fit the inputs, which can make the result less curved and more planar in character. This may help preserve the desired form, but it can also limit how closely the surface conforms to the inputs. The documentation suggests trying small values or very high values above 1000; these are examples for testing the setting’s effect, not universal recommendations.

3. Evaluate the starting surface and boundary options

1. If you have an existing surface similar to the form you want to create, select it as the starting surface with Select starting surface. This lets you base the shape of the new surface on an existing example. The Starting surface pull option affects how closely the resulting surface follows this starting shape; a higher value preserves its form more strongly.

2. Consider the Preserve edges option if you want to keep the starting surface’s edges in place. This option is described for cases where you deform an existing surface with curves or points but need its edges to remain stationary. If Delete input is enabled, the starting surface is deleted after the new surface is created. The documentation also notes that History is not recorded with this option. Check your selection if you need to retain the starting surface or its History relationship.

3. If the input curves are edges of existing surfaces, Adjust tangency can help match their tangent directions. Automatic trim attempts to find the outer boundary and trim the surface accordingly. Verify the results of both options in the command preview; after changing settings, press Preview again to refresh the view.

4. Check the result and switch to an alternative command if needed

1. In the preview, inspect the boundaries, intermediate curves, and the effect of the starting surface together. If the result differs from what you expected, review not only individual settings but also the order of the input curves and the selected starting surface.

2. If Patch does not produce a suitable surface, Rhino’s documentation suggests trying Sweep2. This tool creates a surface by using profile curves along two rail curves. Choose the tool based on the type of inputs available and how you want to define the surface.

Do not use the Join command as a fix to close a gap in a surface. Join groups adjacent surfaces together; it does not change the surface geometry. According to Rhino’s documentation, this helps when creating meshes, performing Boolean operations, and allowing intersections to pass through joined seams without gaps. Changing the geometry or closing the gap requires other surface-editing or surface-creation commands. Join also breaks the History link on objects.

5. Track changes with History

Rhino 8’s documentation lists Patch among the commands that can use History recording. History stores the relationship between a command’s inputs and the result it creates. To have the result update automatically when an input is edited, History recording must be enabled and the Update option must also be on. If Update is off, the documentation shows the HistoryUpdate command for manually refreshing the result.

Recording History only for the commands that need it is a more controlled approach. The Record History field in the status bar enables recording for the current or next command; Always Record History records continuously for supported commands. The documentation states that History uses computer resources and can increase file size. For this reason, it may be useful not to leave the general option enabled all the time when recording is not needed.

To preserve the link, do not delete input objects or directly edit or move the result surface using control points. Moving input and result objects together can also break the History relationship. Joining objects after completing the surface breaks the link as well. If you no longer need the history, you can use HistoryPurge; however, this operation cannot be undone.

In architecture, interior design, and archviz workflows, Patch can be used to explore freeform geometry defined by curves, points, and existing surfaces. If changes to the form need to be tracked, consider the History and Update settings while accounting for file size and resource use. The documentation does not specify particular hardware requirements or licensing terms, so no further assumptions can be made on these points.

Common mistakes

• Assuming Automatic trim will find the expected boundary without selecting closed boundary curves in an order where they touch.

• Expecting every Patch result to pass exactly through all input curves.

• Forgetting to refresh Preview after changing a setting.

• Treating the minimum of eight sample points per curve as a recommended Sample point spacing value.

• Assuming Join fixes the surface geometry or closes a gap.

• Overlooking that the Update option is also required for automatic updates with History.

• Failing to check how Delete input and Join affect History.