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SoPolygonOffset Class

Property node that sets the polygon offset.

Inheritance Hierarchy

Namespace: OIV.Inventor.Nodes
Assembly: OIV.Inventor (in OIV.Inventor.dll) Version: 2024.1.2.0 (2024.1.2)
Syntax
public class SoPolygonOffset : SoNode

The SoPolygonOffset type exposes the following members.

Constructors
  NameDescription
Public methodSoPolygonOffset

Constructor.

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Methods
  NameDescription
Public methodAffectsState

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

(Inherited from SoNode.)
Public methodCallback
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 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
(Inherited from SoNode.)
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 SoNode.)
Public methodGetName

Returns the name of an instance.

(Inherited from SoBase.)
Public methodGetPrimitiveCount
(Inherited from SoNode.)
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 SoNode.)
Public methodHasDefaultValues

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

(Inherited from SoFieldContainer.)
Public methodIsBoundingBoxIgnoring

This method is used by getBoundingBox action traversal to know if the current node must be traversed or not, ie the bounding should be ignored.

(Inherited from SoNode.)
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 field.

(Overrides SoNodeIsOverride.)
Public methodIsSynchronizable

Gets the ScaleViz synchronizable state of this object.

(Inherited from SoBase.)
Public methodPick
(Inherited from SoNode.)
Public methodRayPick
(Inherited from SoNode.)
Public methodSearch
(Inherited from SoNode.)
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

Set the state of the override field.

(Overrides SoNodeSetOverride(Boolean).)
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 SoNode.)
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Properties
  NameDescription
Public propertyfactor

Specifies a scale factor that is used to create a variable depth offset for each polygon.

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

Enables/disables polygon offset.

Public propertystyles

A bit-wise combination of FILLED, LINES, and POINTS that determines which polygon modes should be offset.

Public propertyunits

Is multiplied by an OpenGL implementation-specific value to create a constant depth offset.

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

This class encapsulates the OpenGL 1.1 glPolygonOffset() function. This node can be used to offset polygons that are at the exact same depth to avoid depth buffer artifacts, commonly called z-buffer stitching.

NOTE: OIV.Inventor.Nodes.SoPolygonOffset, as its name implies, only works with polygonal geometry.

OIV.Inventor.Nodes.SoPolygonOffset affects filled primitives such as OIV.Inventor.Nodes.SoFaceSet and OIV.Inventor.Nodes.SoTriangleStripSet. It also affects lines and points in the limited sense that it affects polygonal primitives when the draw style is set to LINES or POINTS. However, because polygon offset does not affect non-polygonal geometry, primitives such as OIV.Inventor.Nodes.SoLineSet and OIV.Inventor.Nodes.SoPointSet cannot be offset with OIV.Inventor.Nodes.SoPolygonOffset.(). To avoid depth buffer artifacts with mixed polygonal and non-polygonal geometry, you should "push" the polygonal geometry away from the camera.

Note: There is only one offset value (combination of OIV.Inventor.Nodes.SoPolygonOffset.factor and OIV.Inventor.Nodes.SoPolygonOffset.units) in the traversal state at any given time.

The value of the offset is factor * z + r * OIV.Inventor.Nodes.SoPolygonOffset.units, where

  • z is a measurement of the change in depth relative to the screen area of the polygon (commonly called the depth slope), and

  • r is the smallest value that is guaranteed to produce a resolvable offset for a given OpenGL implementation.

So units produces a constant depth offset and factor produces a variable depth offset which is zero when a polygon is perpendicular to the view vector (parallel to the view plane) and increases as the depth slope increases.

Both factor and units may be either positive or negative. A positive offset value pushes primitives away from the camera and a negative value pulls them closer. Generally a small value, like 1.0, is sufficient for both parameters.

FILE FORMAT/DEFAULT

PolygonOffset {
factor 1
units 100
styles FILLED
on true
}

ACTION BEHAVIOR

OIV.Inventor.Actions.SoGLRenderAction Calls glPolygonOffset and enables or disables the polygon offset feature as specified. Sets: SoPolyonOffsetElement.

See Also