- All Implemented Interfaces:
public class SoBillboard extends SoSeparatorGrouping node that modifies its coordinate system so that its local Z-axis always points at the viewer. The
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.
- The orientation of an
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
- We recommend leaving the
useSphereBBoxfield set to true.
This will significantly improve performance when using billboard nodes.
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".
axisOfRotationfield specifies which axis to use to perform the rotation. This axis is defined in the local coordinates of the
SoBillboardnode. 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
axisOfRotationmay also need to be oriented at a similar angle.
A special case of billboarding is screen-alignment
the object rotates to always stay aligned with the viewer even when the viewer elevates, pitches and rolls. This special case is distinguished by setting the
axisOfRotationto (0, 0, 0).
To rotate the
SoBillboardto face the viewer, determine the line between the
SoBillboard's origin and the viewer's position; call this the billboard-to-viewer line. The
axisOfRotationand the billboard-to-viewer line define a plane. The local z-axis of the
SoBillboardis then rotated into that plane, pivoting around the
axisOfRotationand the billboard-to-viewer line are coincident (the same line), then the plane cannot be established, and the rotation results of the
SoBillboardare undefined. For example, if the
axisOfRotationis set to (0,1,0) (Y-axis) and the viewer flies over the
SoBillboardand 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 useSphereBBox true
- Open Inventor 10.0
Nested Class Summary
Nested classes/interfaces inherited from class com.openinventor.inventor.nodes.SoSeparator
SoSeparator.Cachings, SoSeparator.FastEditings, SoSeparator.RenderUnitIds
Nested classes/interfaces inherited from class com.openinventor.inventor.nodes.SoNode
Fields Modifier and Type Field Description
axisOfRotationSpecifies which axis to use to perform the rotation.
useSphereBBoxSpecifies if the bounding box returned by SoBillboard.getBoundingBox() method should be extended to completely contain the bounding sphere of the children.
Fields inherited from class com.openinventor.inventor.nodes.SoSeparator
boundingBoxCaching, fastEditing, pickCulling, renderCaching, renderCulling, renderUnitId
Methods inherited from class com.openinventor.inventor.nodes.SoGroup
addChild, findChild, getChild, getNumChildren, insertChild, removeAllChildren, removeChild, removeChild, replaceChild, replaceChild
Methods inherited from class com.openinventor.inventor.nodes.SoNode
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
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, getName, isDisposable, isSynchronizable, setName, setSynchronizable
public final SoSFVec3f axisOfRotationSpecifies which axis to use to perform the rotation.
public final SoSFBool useSphereBBoxSpecifies if the bounding box returned by SoBillboard.getBoundingBox() method should be extended to completely contain the bounding sphere of the children. This hint avoids bounding box cache breaks due to rotation of the billboard geometry (which changes the default axis aligned bounding box) and provides a significant performance increase when many
SoBillboardnodes are used.
Default is true