com.openinventor.inventor.nodes

Class SoCircularExtrusion

java.lang.Object

com.openinventor.inventor.Inventor

com.openinventor.inventor.misc.SoBase

com.openinventor.inventor.fields.SoFieldContainer

com.openinventor.inventor.nodes.SoNode

com.openinventor.inventor.nodes.SoShape

com.openinventor.inventor.nodes.SoBaseExtrusion

com.openinventor.inventor.nodes.SoCircularExtrusion

All Implemented Interfaces:

SafeDisposable

public class SoCircularExtrusion
extends SoBaseExtrusion

Geometric shape formed by extruding a circle along a 3D spine. The SoCircularExtrusion node is a geometric shape based on a constant radius circle cross section extruded along a three-dimensional polyline (spine). The circle center lies on the spine and the circle lies on the plane normal to the spine at each point. This is similar to specifying an SoExtrusion with a circle cross-section, which is convenient for many applications, but this node has additional advantages because it responds to the SoComplexity value.

The application can specify which caps are created using the fields beginCap and endCap. By default both caps are visible.

The application can specify the visible portion of the shape along the spine using normalized curvilinear coordinates (activeSection). By default the entire spine is visible.

The SoCircularExtrusion representation is dependent on SoComplexity.value. The shape is always simplified when the SoComplexity value is less than 1. Both the cross section (number of segments used for the circle) and the spine (number of points used for the spine) are affected by the simplification. The simplification algorithm approximates the spine by taking into account its curvature. The cross section circle is approximated by at least 10 points. With a SoComplexity value of 0 the extruded shape has the roughest representation.

Approximately the same geometry could be defined using an SoExtrusion node, but that node does not currently respond the SoComplexity value. Likewise the clipping behavior could be obtained using two SoClipPlane nodes, but SoCircularExtrusion uses less memory when the activeSection is a subset of the full spine. These two features make SoCircularExtrusion valuable when a large number of cylindrical objects must be displayed.

The scaleMode field (inherited from SoBaseExtrusion) is used to select the points that will be scaled by the current transformation (for example SoTransform), if any. Translation and rotation are applied in all cases. The options are:

• DEFAULT : Every point in the generated geometry is scaled.
• SPINE_ONLY : Only the spine points are scaled. The cross section points are not scaled, so the cross section shape is undistorted even is scaling is non-uniform.
• SECTION_ONLY : Only the cross section points are scaled. Not currently implemented.
• NONE : SoExtrusion ignores the scaling state. Not currently implemented.

The extrusionMode field (inherited from SoBaseExtrusion) is used to select the extrusion algorithm.

Limitations:
The spine polyline segments must be C0 continous, that is, the spine must be connected at joints. The following segments may be C1 discontinous but be aware that very narrow angles between consecutive polyline semgments can produce odd results with SMOOTH extrusionMode modes. This is especially noticeable when the angles between segments are very small with respect to the radius. In the following images the consecutive points A, B, C in the spine show one of these cases. The problem is at point B whose cross sections are abnormally large.

Spine	Wireframe	Shaded

Since:

Open Inventor 8.6 File format/default:

CircularExtrusion {

beginCap	true
endCap	true
spine	[ 0 0 0, 0 1 0 ]
scaleMode	DEFAULT
extrusionMode	SMOOTH
radius	[ 1 ]
activeSection	[ 0, 1 ]

}

See also:

SoExtrusion, SoComplexity, SoBaseExtrusion

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	SoCircularExtrusion.SpineSimplificationModes

Nested classes/interfaces inherited from class com.openinventor.inventor.nodes.SoBaseExtrusion

SoBaseExtrusion.ExtrusionModes, SoBaseExtrusion.ScaleModes

Nested classes/interfaces inherited from class com.openinventor.inventor.nodes.SoShape

SoShape.ShapeTypes

Nested classes/interfaces inherited from class com.openinventor.inventor.Inventor

Inventor.ConstructorCommand

Field Summary

Fields

Modifier and Type	Field and Description
SoSFVec2f	activeSection Defines the visible section of the spine in normalized coordinates.
static int	DEFAULT Deprecated. Use SoCircularExtrusion.SpineSimplificationModes.DEFAULT instead.
SoSFFloat	radius Radius of the circular cross-section.
static int	RESPECT_MATERIALS Deprecated. Use SoCircularExtrusion.SpineSimplificationModes.RESPECT_MATERIALS instead.
SoSFEnum<SoCircularExtrusion.SpineSimplificationModes>	spineSimplificationMode Defines the spine simplification behavior of the extrusion.

Fields inherited from class com.openinventor.inventor.nodes.SoBaseExtrusion

BASIC, beginCap, endCap, extrusionMode, NONE, scaleMode, SECTION_ONLY, SMOOTH, SMOOTH_WITHOUT_SELF_INTERSECTIONS, spine, SPINE_ONLY

Fields inherited from class com.openinventor.inventor.nodes.SoShape

boundingBoxIgnoring, LINES, POINTS, POLYGONS, TEXT

Fields inherited from class com.openinventor.inventor.Inventor

VERBOSE_LEVEL, ZeroHandle

Constructor Summary

Constructors

Constructor and Description
SoCircularExtrusion() Constructor.

Method Summary

Methods inherited from class com.openinventor.inventor.nodes.SoShape

getShapeType, isPrimitiveRestartAvailable, isPrimitiveRestartAvailable

Methods inherited from class com.openinventor.inventor.nodes.SoNode

affectsState, callback, copy, copy, distribute, doAction, getAlternateRep, getBoundingBox, getByName, getMatrix, getPrimitiveCount, getRenderUnitID, GLRender, GLRenderBelowPath, GLRenderInPath, GLRenderOffPath, grabEventsCleanup, grabEventsSetup, handleEvent, isBoundingBoxIgnoring, isOverride, pick, rayPick, search, setOverride, touch, write

Methods inherited from class com.openinventor.inventor.fields.SoFieldContainer

copyFieldValues, copyFieldValues, enableNotify, fieldsAreEqual, get, getAllFields, getEventIn, getEventOut, getField, getFieldName, hasDefaultValues, isNotifyEnabled, set, setToDefaults

Methods inherited from class com.openinventor.inventor.misc.SoBase

dispose, getEXTERNPROTO, getName, getPROTO, isDisposable, isSynchronizable, setName, setSynchronizable

Methods inherited from class com.openinventor.inventor.Inventor

getAddress, getNativeResourceHandle, startInternalThreads, stopInternalThreads

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT

@Deprecated
public static final int DEFAULT

Deprecated. Use SoCircularExtrusion.SpineSimplificationModes.DEFAULT instead.

RESPECT_MATERIALS

@Deprecated
public static final int RESPECT_MATERIALS

Deprecated. Use SoCircularExtrusion.SpineSimplificationModes.RESPECT_MATERIALS instead.

radius

public final SoSFFloat radius

Radius of the circular cross-section. The default value is 1.

activeSection

public final SoSFVec2f activeSection

Defines the visible section of the spine in normalized coordinates. The default is (0,1) meaning that the entire spine is rendered.

spineSimplificationMode

public final SoSFEnum<SoCircularExtrusion.SpineSimplificationModes> spineSimplificationMode

Defines the spine simplification behavior of the extrusion. . Default is DEFAULT. DEFAULT means spine simplification depends only on geometry. This is appropriate in the typical case where a single material is applied to the entire extrusion. RESPECT_MATERIALS means spine simplification preserves multiple materials (if any) applied to the extrusion. This could reduce rendering performance.

Constructor Detail

SoCircularExtrusion

public SoCircularExtrusion()

Constructor.