This page provides information about the Clipper in V-Ray for Rhino.
Overview
V-Ray Clipper is a geometric primitive that can be used to clip away parts of the scene, as well as subtracts or intersects objects with each other. It is a render-time effect and does not modify the actual scene geometry in any way.
UI Paths
||V-Ray Asset Editor|| > Geometry (right-click) > Clipper
||V-Ray Asset Editor|| > Create Asset (left-click) > Geometries > Clipper
||V-Ray Objects Toolbar|| > Clipper (left-click) > Add Clipping Plane
||V-Ray Objects Toolbar|| > Clipper (right-click) > Make Clipper
Rhino Menus Ribbon
||V-Ray|| > Objects > Convert to Clipper
Creating Clipper
To create a Mesh Clipper, select an object in the scene and right-click the Make Mesh Clipper tool from the V-Ray Geometry toolbar. Use the Gumball tool to drag the object to a preferred position as well as to adjust its angle.
A Clipper can be copied from one object and placed inside another. The object then receives all associated object properties. By applying a material to the object, the Clipper object absorbs the applied material and uses that applied material and UV Mapping for the clipped faces.
If you want a Mesh Clipper which leaves gaps instead of a default or custom material, disable the Use Object Material toggle in the Asset Editor and then choose None from the dropdown list.
The vrayClipper command is an alternative method of creating V-Ray Mesh Clippers. It can also be used to apply or remove existing V-Ray Clippers.
Mesh Clippers do not require a Clipper Plane in order to be created.
The toggle under the Swatch Preview enables/disables the Mesh Clipper. The 
icon in front of the Clipper in the Geometries List also enables/disables the Mesh Clipper. If you disable the Clipper from this icon, it will still be attached to the object and appear in the Viewport but will not affect the rendered image. Mesh Clippers can be removed from the Rhino Properties Panel section or by deleting from the Viewport all objects associated with them.
Detaching an existing Clipper from all objects in the Rhino Viewport will not remove it entirely from the scene. It will remain listed in the V-Ray Asset Editor's Geometry tab, available for later use.
To create a Clipping Plane, left-click the Add Clipper Plane from the V-Ray Geometry toolbar and draw a plane in the viewport. Use the Gumball tool to adjust the position and angle of the Clipping Plane.
It is also possible to create a Clipping Plane via the ClippingPlane command.
It is possible to override Clipper properties with other Clipper properties using the Apply to Selection context option.
Creating Clipper Section
Parameters
Mode – Determines how to use the mesh when Mesh mode is enabled.
Subtract – Clips away anything inside the specified mesh; only renders objects and parts of objects outside of the specified mesh.
Intersect – Clips away anything that is outside the specified mesh; only renders objects and parts of objects inside the specified mesh.
Use Object Material – When enabled, the clipper uses the material of each clipped object to fill in the resulting holes. When disabled, the material applied to the clipper object itself is used.
Material – Specifies the material used by the clipper. This parameter is disabled when object material is used instead.
The input slot (
) of the Material has a context menu available, if a material is slotted. Note that materials can also be drag-and-dropped into the slot. When you right-click on it, you can Copy, Cut or Clear the selected material. If you left-click on it, the Asset Editor jumps to the slotted material.
Options
Affect lights – When enabled, the clipper affects area light sources as well.
Camera Rays Only – When enabled, the clipper affects objects as they are directly seen by the camera, but they appear unchanged to reflection/refraction/GI rays.
Clip Light Geometry– When enabled, the clipper clips light geometry (for example a mesh light).
Clipper in Rhino Properties Panel
The 
button creates new Mesh Clipper. The 
button opens the geometry property panel of the selected Clipper asset in the V-Ray Asset Editor for edition.
Make Unique – Makes the selected instance of a Clipper unique. It creates a new Clipper item in the Asset Editor that is linked only to the selected object.
Select Instances – Selects all objects that have an instance of the same Clipper in the viewport.
Ignore VP state – Disables the Clipping Plane in the rendered image regardless of the Viewport state selected in the Views Clipped list.
Exclusion Mode – Selects the exclusion mode.
Include – The Clipper affects only a predefined selection of objects.
Exclude – The Clipper affects all scene geometry excluding a predefined selection of objects.
Pick Object – Selects objects that are affected by the Clipper based on its Exclusion mode. To reset the list of affected objects, use the button and confirm the action while having an empty selection.
Select Object – Selects the objects affected by the Clipper based on its Exclusion mode
Examples: Ignore VP state
The Ignore VP state option is enabled.
Clipping Plane toggle is disabled. Render view is enabled in the Views Clipped list.
Clipping Plane toggle is enabled. Render view is disabled in the Views Clipped list.
Notes
- V-Ray Clipper works best with "closed" objects. The results on open objects (without a corresponding back face) are not well defined.
- Currently, the V-Ray Clipper may produce artifacts if there are overlapping triangles in the scene, regardless of whether they are part of the same object or not.
- "Views Clipped" list in Rhino's Clipping Plane property panel is respected by V-Ray. Its toggle overrides the V-Ray Clipper toggle in the Asset Editor.
V-Ray Clipper can be instanced by using the _Array command or Alt+drag the clipper object in the Rhino viewport.
Starting with V-Ray 5.20.01, V-Ray special objects (Fur/Clipper/Displacement/Mesh Light/Scatter) are not deleted from the Asset Editor, when the last item with the corresponding special object assigned to it, is deleted from the viewport.