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SoVolumeClippingGroup Class

Clipping a volume with a 3D object.

Inheritance Hierarchy

Namespace: OIV.VolumeViz.Nodes
Assembly: OIV.VolumeViz (in OIV.VolumeViz.dll) Version: 10.12.3.0 (10.12.3.0)
Syntax
public class SoVolumeClippingGroup : SoGroup

The SoVolumeClippingGroup type exposes the following members.

Constructors
  NameDescription
Public methodSoVolumeClippingGroup

Default constructor.

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Methods
  NameDescription
Public methodAddChild

Adds a child as last one in group.

(Inherited from SoGroup.)
Public methodAffectsState

Returns true if a node has an effect on the state during traversal.

(Inherited from SoNode.)
Public methodCallback
(Inherited from SoGroup.)
Public methodCopy
Calls Copy(false).
(Inherited from SoNode.)
Public methodCopy(Boolean)

Creates and returns an exact copy of the node.

(Inherited from SoNode.)
Public methodCopyFieldValues(SoFieldContainer)
Calls CopyFieldValues(fc, false).
(Inherited from SoFieldContainer.)
Public methodCopyFieldValues(SoFieldContainer, Boolean)

Copies the contents of fc's fields into this object's fields.

(Inherited from SoFieldContainer.)
Public methodDispose
Releases all resources used by SoDisposable.
(Inherited from SoDisposable.)
Public methodDistribute
(Inherited from SoNode.)
Public methodDoAction
Public methodEnableNotify

Notification at this Field Container is enabled (if flag == true) or disabled (if flag == false).

(Inherited from SoFieldContainer.)
Public methodEquals
Determines whether the specified Object is equal to the current Object.
(Inherited from Object.)
Public methodFieldsAreEqual

Returns true if this object's fields are exactly equal to fc's fields.

(Inherited from SoFieldContainer.)
Public methodFindChild

Finds index of given child within group.

(Inherited from SoGroup.)
Public methodGet

Returns the values of the fields of this object in the Open Inventor ASCII file format in the given string.

(Inherited from SoFieldContainer.)
Public methodGetAllFields

Returns a list of fields, including the eventIn's and eventOut's.

(Inherited from SoFieldContainer.)
Public methodGetAlternateRep

This method is called by actions to allow the node to provide an "alternate representation" when appropriate (typically depending on the action type).

(Inherited from SoNode.)
Public methodGetBoundingBox
Public methodGetChild

Returns pointer the child node with the given index.

(Inherited from SoGroup.)
Public methodGetEventIn

Returns a the eventIn with the given name.

(Inherited from SoFieldContainer.)
Public methodGetEventOut

Returns the eventOut with the given name.

(Inherited from SoFieldContainer.)
Public methodGetField

Returns a the field of this object whose name is fieldName.

(Inherited from SoFieldContainer.)
Public methodGetFieldName

Returns the name of the given field in the fieldName argument.

(Inherited from SoFieldContainer.)
Public methodGetFields

Appends references to all of this object's fields to resultList, and returns the number of fields appended.

(Inherited from SoFieldContainer.)
Public methodGetHashCode
Overrides GetHashCode().
(Inherited from SoNetBase.)
Public methodGetMatrix
(Inherited from SoGroup.)
Public methodStatic memberGetMaxNumPasses

Returns the maximum number of passes supported by the hardware.

Public methodGetName

Returns the name of an instance.

(Inherited from SoBase.)
Public methodGetNumChildren

Returns number of children.

(Inherited from SoGroup.)
Public methodGetPrimitiveCount
(Inherited from SoGroup.)
Public methodGetRenderEngineMode

Returns the supported Render engine mode.

(Inherited from SoNode.)
Public methodGetRenderUnitID
(Inherited from SoNode.)
Public methodGetStringName (Inherited from SoBase.)
Public methodGetType
Gets the Type of the current instance.
(Inherited from Object.)
Public methodGLRender
Public methodGLRenderBelowPath
(Inherited from SoNode.)
Public methodGLRenderInPath
(Inherited from SoNode.)
Public methodGLRenderOffPath
(Inherited from SoNode.)
Public methodGrabEventsCleanup
(Inherited from SoNode.)
Public methodGrabEventsSetup
(Inherited from SoNode.)
Public methodHandleEvent
(Inherited from SoGroup.)
Public methodHasDefaultValues

Returns true if all of the object's fields have their default values.

(Inherited from SoFieldContainer.)
Public methodInsertChild

Adds a child so that it becomes the one with the given index.

(Inherited from SoGroup.)
Public methodIsBoundingBoxIgnoring

Used by BoundingBoxAction to known if bounding box computation should be ignored or not.

(Inherited from SoGroup.)
Public methodIsNotifyEnabled

Notification is the process of telling interested objects that this object has changed.

(Inherited from SoFieldContainer.)
Public methodIsOverride

Returns the state of the override flag.

(Inherited from SoNode.)
Public methodIsSynchronizable

Gets the ScaleViz synchronizable state of this object.

(Inherited from SoBase.)
Public methodPick
(Inherited from SoGroup.)
Public methodRayPick
Public methodRemoveAllChildren

Removes all children from group.

(Inherited from SoGroup.)
Public methodRemoveChild(Int32)

Removes child with given index from group.

(Inherited from SoGroup.)
Public methodRemoveChild(SoNode)

Removes first instance of given child from group.

(Inherited from SoGroup.)
Public methodReplaceChild(Int32, SoNode)

Replaces child with given index with new child.

(Inherited from SoGroup.)
Public methodReplaceChild(SoNode, SoNode)

Replaces first instance of given child with new child.

(Inherited from SoGroup.)
Public methodSearch
(Inherited from SoGroup.)
Public methodSet

Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format.

(Inherited from SoFieldContainer.)
Public methodSetName (Inherited from SoBase.)
Public methodSetOverride

Turns the override flag on or off.

(Inherited from SoNode.)
Public methodSetSynchronizable

Sets this to be a ScaleViz synchronizable object.

(Inherited from SoBase.)
Public methodSetToDefaults

Sets all fields in this object to their default values.

(Inherited from SoFieldContainer.)
Public methodToString
Converts this SoBase structure to a human readable string.
(Inherited from SoBase.)
Public methodTouch

Marks an instance as modified, simulating a change to it.

(Inherited from SoNode.)
Public methodWrite
(Inherited from SoGroup.)
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Properties
  NameDescription
Public propertyboundingBoxIgnoring

Whether to ignore this node during bounding box traversal.

(Inherited from SoGroup.)
Public propertyclipOutside

If true, voxels inside the clipping object will be drawn, voxels outside will be clipped.

Public propertyIsDisposable
ISafeDisposable interface implementation.
(Inherited from SoDisposable.)
Public propertyNotEnoughPassCallback

Set a callback to be called when there are not enough passes (see OIV.VolumeViz.Nodes.SoVolumeClippingGroup.numPasses) to properly apply the clipping.

Public propertynumPasses

Number of passes used to do the clipping.

Public propertyUserData
Gets or sets the user data to be contained by the field container.
(Inherited from SoFieldContainer.)
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Remarks

VolumeViz supports clipping a volume against any closed 3D polygonal shape defined by standard Open Inventor geometry. This is done using the OIV.VolumeViz.Nodes.SoVolumeClippingGroup node. Polygon clipping can remove the voxels outside the shape or the voxels inside the shape. Polygon clipping can be used in seismic applications to clip outside a fault block or geobody, in medical applications to cut away an arbitrary region, in core sample applications to apply cylindrical clipping and many other uses.

When this node is in the scene graph before a VolumeViz rendering node, all shapes under the OIV.VolumeViz.Nodes.SoVolumeClippingGroup will be used to clip the volume. These shapes will not be displayed.

The geometry defined under OIV.VolumeViz.Nodes.SoVolumeClippingGroup must represent a set of closed surfaces otherwise the result is unpredictable.

The clipping group may include transform nodes, e.g. OIV.Inventor.Nodes.SoTransform, to scale, rotate and translate the geometry. The transformed geometry will be used for clipping.

In general, do not put draggers or manipulators, e.g. OIV.Inventor.Draggers.SoTabBoxDragger, in the clipping group. The geometry of the dragger will also be used for clipping and the results may be unexpected. One exception is if the dragger is configured to use the clipping shape as "proxy" geometry (see OIV.Inventor.Nodekits.SoInteractionKit.SetPartAsPath(System.String, OIV.Inventor.SoPath)). A better solution is to put the dragger in the scene graph outside the clipping group, add a transform node to the clipping group and connect the fields of the dragger to the fields of the transform node (see OIV.Inventor.Fields.SoField.ConnectFrom(OIV.Inventor.Engines.SoEngineOutput)).

The clipping result is based on the odd-winding rule, so the result is not simply the union or the intersection of the closed surfaces. If the goal is to define a clipping shape which is the result of the intersection/union of multiple closed surfaces, consider using the OIV.Inventor.Nodes.SoCSGShape node as a child of OIV.VolumeViz.Nodes.SoVolumeClippingGroup.

In some cases the number of passes specified may not be enough to clip correctly with the specified geometry. The OIV.VolumeViz.Nodes.SoVolumeClippingGroup.numPasses field allows you to increase the clipping quality, for example when using shapes with a lot of concavity. To query the maximum allowed number of passes, which depends on your graphics card, use the static method GetMaxNumPasses().The SetNotEnoughPassCallback()method allows the application to be notified when numPasses is not sufficient.

Standard clipplanes (see OIV.Inventor.Nodes.SoClipPlane) affect VolumeViz rendering nodes, but the VolumeViz specific clipping nodes generally provide better performance and allow much more complex clipping. Simple axis-aligned clipping can be done more efficiently using the OIV.LDM.Nodes.SoROI node. The OIV.VolumeViz.Nodes.SoUniformGridClipping or OIV.VolumeViz.Nodes.SoUniformGridProjectionClipping nodes clip against height-field surfaces (e.g. seismic horizons). The OIV.VolumeViz.Nodes.SoVolumeMask node clips against a boolean mask volume on a per-voxel basis.

Notes:

  • When using a custom OIV.VolumeViz.Nodes.SoVolumeShader with this node and redefining the main() function, you must call VVizClipVoxel() in the main() function if you are writing a fragment shader. If you don't do this you will get a GLSL compilation error or clipping won't work.

  • Because this node uses special textures, all texture units between IVVR_FIRST_RESERVED_TEXTURE_UNIT (or OIV.Inventor.Nodes.SoFragmentShader.GetMaxTextureImageUnit()-SoShaderProgram.getNumReservedTextures() if this variable is not set) and IVVR_FIRST_RESERVED_TEXTURE_UNIT-2 are reserved.

  • Because this node requires closed geometry, clipping planes (OIV.Inventor.Nodes.SoClipPlane) are automatically disabled when computing the clipping shape.

  • When used inside an OIV.VolumeViz.Nodes.SoOffscreenVolumeRender results might be incorrect. In specific cases geometry might be seen as opened.

EXAMPLE

The following code clips a volume with a cone:

SoVolumeClippingGroup volClipGroup = new SoVolumeClippingGroup();
 volClipGroup.AddChild( new SoCone() );

SoSeparator volSep = new SoSeparator();
 volSep.AddChild( volumeData );
 volSep.AddChild( transferFunction );
 volSep.AddChild( volClipGroup );
 volSep.AddChild( volumeRender );
root.AddChild( volSep );

Clipping object Clipping applied to a volume

FILE FORMAT/DEFAULT

VolumeClippingGroup {
numPasses 2
clipOutside true
}

See Also