public class SoCircularExtrusion extends SoBaseExtrusion
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:
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 |
![]() | ![]() | ![]() |
CircularExtrusion {
beginCap | true |
endCap | true |
spine | [ 0 0 0, 0 1 0 ] |
scaleMode | DEFAULT |
extrusionMode | SMOOTH |
radius | [ 1 ] |
activeSection | [ 0, 1 ] |
See also:
Modifier and Type | Class and Description |
---|---|
static class |
SoCircularExtrusion.SpineSimplificationModes |
SoBaseExtrusion.ExtrusionModes, SoBaseExtrusion.ScaleModes
SoShape.ShapeTypes
SoNode.RenderModes
Inventor.ConstructorCommand
Modifier and Type | Field and Description |
---|---|
SoSFVec2f |
activeSection
Defines the visible section of the spine in normalized coordinates.
|
SoSFFloat |
radius
Radius of the circular cross-section.
|
SoSFEnum<SoCircularExtrusion.SpineSimplificationModes> |
spineSimplificationMode
Defines the spine simplification behavior of the extrusion.
|
beginCap, endCap, extrusionMode, scaleMode, spine
boundingBoxIgnoring
VERBOSE_LEVEL, ZeroHandle
Constructor and Description |
---|
SoCircularExtrusion()
Constructor.
|
getShapeType, isPrimitiveRestartAvailable, isPrimitiveRestartAvailable
affectsState, callback, copy, copy, distribute, doAction, getAlternateRep, getBoundingBox, getByName, getMatrix, getPrimitiveCount, getRenderEngineMode, getRenderUnitID, GLRender, GLRenderBelowPath, GLRenderInPath, GLRenderOffPath, grabEventsCleanup, grabEventsSetup, handleEvent, isBoundingBoxIgnoring, isOverride, pick, rayPick, search, setOverride, touch, write
copyFieldValues, copyFieldValues, enableNotify, fieldsAreEqual, get, getAllFields, getEventIn, getEventOut, getField, getFieldName, hasDefaultValues, isNotifyEnabled, set, setToDefaults
dispose, getName, isDisposable, isSynchronizable, setName, setSynchronizable
getNativeResourceHandle
public final SoSFFloat radius
public final SoSFVec2f activeSection
public final SoSFEnum<SoCircularExtrusion.SpineSimplificationModes> spineSimplificationMode
Generated on July 31, 2019, Copyright © Thermo Fisher Scientific. All rights reserved. http://www.openinventor.com