com.openinventor.inventor.vrmlnodes

Class SoVRMLLOD

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.SoGroup

com.openinventor.inventor.vrmlnodes.SoVRMLParent

com.openinventor.inventor.vrmlnodes.SoVRMLLOD

All Implemented Interfaces:

SafeDisposable

Deprecated.

As of Open Inventor 9500 See documentation for more details

public class SoVRMLLOD
extends SoVRMLParent

Distance-based level-of-detail switching group node. The SoVRMLLOD node allows applications to switch between various levels of detail or complexity for a given object, based on the distance from the user.

<font color="#0000FF">NOTE:</font> This class does not exist in Open Inventor 10.0 and later.

NOTE: This node contains three fields inherited from SoVRMLParent that are new in Open Inventor 5.0. These fields are children (replaces the level field for X3D), bboxCenter, and bboxSize. If you specify a non-default value for this field, when this node is written to an Inventor file, the file will contain this new field. Older versions of Open Inventor will not be able to read this file and will generate an Inventor read error (unknown field).
NOTE 2: This field is not compatible with VRML97. If you specify a non-default value for this field, when this node is written to a VRML file, the file will contain this incompatible field and standard VRML97 file readers will not be able to read it.

The level field contains a list of nodes that represent the same object or objects at varying levels of detail, from highest to the lowest level of detail, and the range field specifies the ideal distances at which to switch between the levels.

The center field is a translation offset in the local coordinate system that specifies the center of the SoVRMLLOD object for distance calculations. In order to calculate which level to display, first the distance is calculated from the viewpoint, transformed into the local coordinate space of the SoVRMLLOD node, (including any scaling transformations), to the center point of the SoVRMLLOD. If the distance is less than the first value in the range field, then the first level of the SoVRMLLOD is drawn. If between the first and second values in the range field, the second level is drawn, and so on.

If there are N values in the range field, the SoVRMLLOD must have N+1 nodes in its level field. Specifying too few levels will result in the last level being used repeatedly for the lowest levels of detail; if more levels than ranges are specified, the extra levels will be ignored. The exception to this rule is to leave the range field empty, which is a hint to the browser that it should choose a level automatically to maintain a constant display rate. Each value in the range field should be greater than the previous value; otherwise results are undefined.

Note that the selection of which child to render depends on the current camera settings, so generally this node should not be render cached. SoVRMLLOD nodes prohibit auto-caching, so that no SoSeparator (or other render caching node) above an SoVRMLLOD in the scene graph will automatically create a render cache. This can significantly affect performance and applications should try to keep nodes that can be render cached (especially geometry nodes) under a different SoSeparator.

VRML97 SPECIFICATION

This section describes the expected behavior of the node in a conforming VRML97 browser application. In some cases, the application is responsible for implementing portions of the expected behavior. Open Inventor viewer classes and IVF classes implement some of the application behaviors.

This section may reference portions of the VRML97 specification that are not present in this help file. The complete VRML97 spec is available at http://www.web3d.org.

The SoVRMLLOD node specifies various levels of detail or complexity for a given object, and provides hints for browsers to automatically choose the appropriate version of the object based on the distance from the user. The level field contains a list of nodes that represent the same object or objects at varying levels of detail, from highest to the lowest level of detail, and the range field specifies the ideal distances at which to switch between the levels. See the "Concepts - Grouping and Children Nodes" section for a details on the types of nodes that are legal values for level.

The center field is a translation offset in the local coordinate system that specifies the center of the SoVRMLLOD object for distance calculations. In order to calculate which level to display, first the distance is calculated from the viewpoint, transformed into the local coordinate space of the SoVRMLLOD node, (including any scaling transformations), to the center point of the SoVRMLLOD. If the distance is less than the first value in the range field, then the first level of the SoVRMLLOD is drawn. If between the first and second values in the range field, the second level is drawn, and so on.

If there are N values in the range field, the SoVRMLLOD must have N+1 nodes in its level field. Specifying too few levels will result in the last level being used repeatedly for the lowest levels of detail; if more levels than ranges are specified, the extra levels will be ignored. The exception to this rule is to leave the range field empty, which is a hint to the browser that it should choose a level automatically to maintain a constant display rate. Each value in the range field should be greater than the previous value; otherwise results are undefined.

Authors should set SoVRMLLOD ranges so that the transitions from one level of detail to the next are smooth. Browsers may adjust which level of detail is displayed to maintain interactive frame rates, to display an already-fetched level of detail while a higher level of detail (contained in an Inline node) is fetched, or might disregard the author-specified ranges for any other implementation-dependent reason. For best results, specify ranges only where necessary, and nest SoVRMLLOD nodes with and without ranges. Browsers should try to honor the hints given by authors, and authors should try to give browsers as much freedom as they can to choose levels of detail based on performance.

SoVRMLLOD nodes are evaluated top-down in the scene graph. Only the descendants of the currently selected level are rendered and evaluated. Note that all nodes under an SoVRMLLOD node continue to receive and send events regardless of which SoVRMLLODlevel is active.

File format/default:

VRMLLOD {

level	[] // VRML97 only
children	[] // X3D only
center	0 0 0
range	[]
bboxCenter	0 0 0
bboxSize	-1 -1 -1
metadata	NULL

}

Action behavior:

SoGLRenderAction, SoCallbackAction, SoGetBoundingBoxAction, SoRayPickAction, SoSearchAction, SoWriteAction

EVENTS

eventIn

SoMFNode	set_level // VRML97 only
SoMFNode	set_children // X3D only
SoSFNode	set_metadata

eventOut

SoMFNode	level_changed // VRML97 only
SoMFNode	children_changed // X3D only
SoSFNode	metadata_changed

Deprecated since Open Inventor 9500
The VRML API is no longer supported. See section http://oivdoc95.vsg3d.com/content/compatibility-notes-4#Deprecation of the Reference Manual.

Nested Class Summary

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

Inventor.ConstructorCommand

Field Summary

Fields

Modifier and Type	Field and Description
SoSFVec3f	center Deprecated. Translation offset in the local coordinate system that specifies the center of the SoVRMLLOD objects.
SoMFNode	level Deprecated. List of nodes that request the same object or objects at varying levels of detail from highest to lowest (VRML97).
SoMFFloat	range Deprecated. Specifies the ideal distances at which to switch between the levels.

Fields inherited from class com.openinventor.inventor.vrmlnodes.SoVRMLParent

bboxCenter, bboxSize, children, metadata

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

boundingBoxIgnoring

Fields inherited from class com.openinventor.inventor.Inventor

VERBOSE_LEVEL, ZeroHandle

Constructor Summary

Constructors

Constructor and Description
SoVRMLLOD() Deprecated. Constructor.
SoVRMLLOD(int nLevels) Deprecated. Constructor that takes approximate number of levels/children.

Method Summary

Modifier and Type	Method and Description
void	addLevel(SoNode level1) Deprecated. Adds a level/child as last one in group.
int	findLevel(SoNode level1) Deprecated. Finds index of given level/child within group.
SoNode	getLevel(int index) Deprecated. Returns the nth level/child node.
int	getNumLevels() Deprecated. Returns number of levels/children.
void	insertLevel(SoNode level1, int newLevelIndex) Deprecated. Adds a level/child so that it becomes the one with the given index.
void	removeAllLevels() Deprecated. Removes all levels/children from group.
void	removeLevel(int index) Deprecated. Removes level/child with given index from group.
void	removeLevel(SoNode level1) Deprecated. Removes first instance of given level/child from group.
void	replaceLevel(int index, SoNode newLevel) Deprecated. Replaces level with given index with new level/child.
void	replaceLevel(SoNode oldLevel, SoNode newLevel) Deprecated. Replaces first instance of given level/child with new level/child.

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, 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

range

public final SoMFFloat range

Deprecated.

Specifies the ideal distances at which to switch between the levels.

center

public final SoSFVec3f center

Deprecated.

Translation offset in the local coordinate system that specifies the center of the SoVRMLLOD objects.

level

public final SoMFNode level

Deprecated.

List of nodes that request the same object or objects at varying levels of detail from highest to lowest (VRML97). In X3D, the list of nodes is specified using the children field (inherited from SoVRMLParent).

NOTE: The children field is a new field in SoVRMLLOD added in Open Inventor 5.0. If you specify a non-default value for this field, when this node is written to an Inventor file, the file will contain this new field. Older versions of Open Inventor will not be able to read this file and will generate an Inventor read error (unknown field).
NOTE 2: This field is not compatible with VRML97. If you specify a non-default value for this field, when this node is written to a VRML file, the file will contain this incompatible field and standard VRML97 file readers will not be able to read it.

Constructor Detail

SoVRMLLOD

public SoVRMLLOD(int nLevels)

Deprecated.

Constructor that takes approximate number of levels/children.

SoVRMLLOD

public SoVRMLLOD()

Deprecated.

Constructor.

Method Detail

removeAllLevels

public void removeAllLevels()

Deprecated.

Removes all levels/children from group.

replaceLevel

public void replaceLevel(int index,
                         SoNode newLevel)

Deprecated.

Replaces level with given index with new level/child.

addLevel

public void addLevel(SoNode level1)

Deprecated.

Adds a level/child as last one in group.

getNumLevels

public int getNumLevels()

Deprecated.

Returns number of levels/children.

findLevel

public int findLevel(SoNode level1)

Deprecated.

Finds index of given level/child within group.

getLevel

public SoNode getLevel(int index)

Deprecated.

Returns the nth level/child node.

removeLevel

public void removeLevel(int index)

Deprecated.

Removes level/child with given index from group.

insertLevel

public void insertLevel(SoNode level1,
                        int newLevelIndex)

Deprecated.

Adds a level/child so that it becomes the one with the given index.

removeLevel

public void removeLevel(SoNode level1)

Deprecated.

Removes first instance of given level/child from group.

replaceLevel

public void replaceLevel(SoNode oldLevel,
                         SoNode newLevel)

Deprecated.

Replaces first instance of given level/child with new level/child.