SoText2 Class Reference

Screen-aligned 2D text shape node. More...

#include <Inventor/nodes/SoText2.h>

Inheritance diagram for SoText2:
SoShape SoNode SoFieldContainer SoBase SoRefCounter SoTypedObject

List of all members.

Public Types

enum  Justification {
  LEFT = 0x01,
  CENTER = 0x03,
  RIGHT = 0x02,
  INHERITED = 0x04

Public Member Functions

virtual SoType getTypeId () const
 SoText2 ()

Static Public Member Functions

static SoType getClassTypeId ()

Public Attributes

SoMFString string
SoSFFloat spacing
SoSFEnum justification


class SoAnnoText3

Detailed Description

Screen-aligned 2D text shape node.

This node defines one or more strings of 2D text. The text is always horizontal, aligned with the screen and does not change size with distance from the camera. However the position of the text is specified in 3D units and is affected by viewing and modeling transformations. 2D text cannot be rotated, but because it always faces the user, it is often used for annotation, for example labels on axes.

The text position is always at the local origin (0,0,0). Rotations and scales have no effect on the orientation or size of 2D text, just the location.

Note: A transform node, e.g. SoTranslation, must be used to position the text in 3D space.

Text supports both single byte Latin1 (ISO8859-1) characters and multi-byte UNICODE characters. ISO8859-1 is an 8-bit character set which is a superset of the older 7-bit ASCII character set. See the SbString class for more information.


The typeface and size (default = 10) are specified using an SoFont node. Note that for SoText2 the size is interpreted as a value in pixels, not 3D units.

Setting the SoFont renderStyle field to TEXTURE is recommended for best appearance and performance. (antialiasing is applied).

Additional rendering styles can be applied using an SoTextProperty node, including underline, overline, strikethrough, background and background outline.

SoText2 is drawn using the diffuse color of the current material (SoMaterial). Lighting is not applied, regardless of the lighting model. Textures do not affect SoText2 (note this is independent of the fact that textures are used internally to render SoText2). Complexity (SoComplexity) does not affect SoText2. Drawing styles (SoDrawStyle) other than INVISIBLE do not affect SoText2.


Horizontal alignment of the text can be specified using the justification field. Both horizontal and vertical alignment can be controlled using an SoTextProperty node, however the justification setting in the SoText2 node overrides the horizontal setting unless it is explicitly set to INHERITED.


If the transformed position (origin point) of the SoText2 is clipped, then the entire string is clipped, even if some part of the string should conceptually be visible. If the origin point is inside the view volume then the string is clipped similar to other geometry.

Bounding box:

Because 2D text is screen-aligned, it has some unusual characteristics. For example, the 3D bounding box surrounding a 2D text string depends on the current camera and the current viewport size, since changing the field of view or the mapping onto the window changes the relative size of the text with respect to the rest of the scene.

When computing the bounding box of a 2D text node (see SoGetBoundingBoxAction), be careful to:


Text can be picked (SoRayPickAction) like any other geometry. If a text node has been picked then SoPickedPoint can return an SoTextDetail object. This object contains information about which string (in a multi-string text node) was picked and which character within the string was picked.

Render caching:

If your Open Inventor version is older than 9.2, then SoText2 nodes using CENTER or RIGHT justification cannot be render cached because the bounding box and justification offset depend on the camera. As a result, no SoSeparator above the SoText2 will be able to build a render cache or a bounding box cache and this can reduce performance. If possible put other geometry, that can be cached, under its own SoSeparator. SoText2 nodes using LEFT justification (the default) can be cached. Since Open Inventor 9.2, SoText2 nodes can be render cached in all cases.

Shape Antialiasing type is SoShape::TEXT.

Export limitations:




SoFont, SoFullSceneAntialiasing, SoText3, SoTextDetail, SoTextProperty

See related examples:


Member Enumeration Documentation

Justification types.


Left edges of all strings are aligned.


Centers of all strings are aligned.


Right edges of all strings are aligned.


The text justification is inherited from the current SoTextProperty::alignmentH value.

Constructor & Destructor Documentation

SoText2::SoText2 (  ) 

Creates a 2D text node with default settings.

Member Function Documentation

static SoType SoText2::getClassTypeId (  )  [static]

Returns the type identifier for this class.

Reimplemented from SoShape.

virtual SoType SoText2::getTypeId (  )  const [virtual]

Returns the type identifier for this specific instance.

Reimplemented from SoShape.

Friends And Related Function Documentation

friend class SoAnnoText3 [friend]

Member Data Documentation

Specifies horizontal alignment of strings.

With LEFT justification, the left edge of the first line is at the (transformed) origin, and all left edges are aligned. RIGHT justification is similar. CENTER justification places the center of the first string at the (transformed) origin, with the centers of all remaining strings aligned under it. Use enum Justification. Default is LEFT.

Both horizontal and vertical alignment can be specified using an SoTextProperty node. However the justification setting in this node overrides the horizontal setting in SoTextProperty unless this field is set to INHERITED.

Defines the distance (in the negative y direction) between the base points of successive strings, measured with respect to the current font height.

A value of 1 indicates single spacing, a value of 2 indicates double spacing, and so on.

The text string(s) to display.

Each string will appear on its own line.

The documentation for this class was generated from the following file:

Open Inventor by FEI reference manual, generated on 20 Aug 2019
Copyright © FEI S.A.S. All rights reserved.