public class SoBillboard extends SoSeparator
SoBillboardnode is a grouping node which modifies its coordinate system so that the billboard node's local Z-axis turns to point at the viewer. The children of an
SoBillboardnode may include other grouping nodes as well as shape nodes.
SoBillboardnodes recompute the screen alignment transformation on every render traversal. A large number of billboard nodes will reduce performance.
SoBillboarddepends on the current camera settings, so this node should not be render cached.
SoBillboardnodes prohibit auto-caching, so no
SoSeparator(or other render caching node) above an
SoBillboardin the scene graph will automatically create a render cache. This can significantly reduce performance and applications should put nodes that can be render cached (especially geometry nodes) under their own
useSphereBBoxfield to true.
SoBillboardcan be exported to PDF3D/U3D (
SoToPDFAction) as a group node, but due to limitations of that file format, it will not act as a billboard. In other words, the geometry will not be "screen locked".
axisOfRotation field specifies which axis to use to perform the rotation. This axis is defined in the local coordinates of the
SoBillboard node. The default (0,1,0) is useful for objects such as images of trees and lamps positioned on a ground plane. But when an object is oriented at an angle, for example, on the incline of a mountain, then the
axisOfRotation may also need to be oriented at a similar angle.
A special case of billboarding is
axisOfRotation to (0, 0, 0).
To rotate the
SoBillboard to face the viewer, determine the line between the
SoBillboard's origin and the viewer's position; call this the billboard-to-viewer line. The
axisOfRotation and the billboard-to-viewer line define a plane. The local z-axis of the
SoBillboard is then rotated into that plane, pivoting around the
axisOfRotation and the billboard-to-viewer line are coincident (the same line), then the plane cannot be established, and the rotation results of the
SoBillboard are undefined. For example, if the
axisOfRotation is set to (0,1,0) (Y-axis) and the viewer flies over the
SoBillboard and peers directly down the Y-axis the results are undefined .
Multiple instances of SoBillboards (DEF/USE) operate as expected - each instance rotates in its unique coordinate system to face the viewer.
|axisOfRotation||0 1 0|
SoSeparator.Cachings, SoSeparator.FastEditings, SoSeparator.RenderUnitIds
|Modifier and Type||Field and Description|
Specifies which axis to use to perform the rotation.
Specifies if the bounding box returned by SoBillboard.getBoundingBox() method should be extended to completely contain the bounding sphere of the children.
AUTO, boundingBoxCaching, CLEAR_ZBUFFER, directVizCaching, DISABLE, fastEditing, KEEP_ZBUFFER, OFF, ON, pickCulling, renderCaching, renderCulling, renderUnitId
|Constructor and Description|
Constructor that takes approximate number of children.
addChild, findChild, getChild, getNumChildren, insertChild, removeAllChildren, removeChild, removeChild, replaceChild, replaceChild
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
copyFieldValues, copyFieldValues, enableNotify, fieldsAreEqual, get, getAllFields, getEventIn, getEventOut, getField, getFieldName, hasDefaultValues, isNotifyEnabled, set, setToDefaults
dispose, getEXTERNPROTO, getName, getPROTO, isDisposable, isSynchronizable, setName, setSynchronizable
getAddress, getNativeResourceHandle, startInternalThreads, stopInternalThreads
public final SoSFVec3f axisOfRotation
public final SoSFBool useSphereBBox
SoBillboardnodes are used.
Default is true
Generated on September 3, 2019, Copyright © Thermo Fisher Scientific. All rights reserved. http://www.openinventor.com