SoSceneTexture2(3)

NAME
SoSceneTexture2 - The SoSceneTexture2 class is used to create a 2D texture from a Coin scene graph.

Lets the rendering of a scene graph be specified as a texture image to be used in another scene graph. Set up the scene graph used for a texture in the SoSceneTexture2::scene field.

SYNOPSIS

#include <Inventor/nodes/SoSceneTexture2.h>

Inherits SoNode.

  Public Types
enum Model { MODULATE = SoTextureImageElement::MODULATE, DECAL = SoTextureImageElement::DECAL, BLEND = SoTextureImageElement::BLEND, REPLACE = SoTextureImageElement::REPLACE }
enum Wrap { REPEAT = SoTextureImageElement::REPEAT, CLAMP = SoTextureImageElement::CLAMP, CLAMP_TO_BORDER = SoTextureImageElement::CLAMP_TO_BORDER }
enum TransparencyFunction { NONE, ALPHA_BLEND, ALPHA_TEST }
enum Type { DEPTH, RGBA8, RGBA32F, RGB32F, RGBA16F, RGB16F, R3_G3_B2, RGB, RGB4, RGB5, RGB8, RGB10, RGB12, RGB16, RGBA, RGBA2, RGBA4, RGB5_A1, RGB10_A2, RGBA12, RGBA16 }

  Public Member Functions
virtual SoType getTypeId (void) const
virtual void notify (SoNotList *list)
virtual void write (SoWriteAction *action)
virtual void doAction (SoAction *action)
virtual void GLRender (SoGLRenderAction *action)
virtual void callback (SoCallbackAction *action)
virtual void rayPick (SoRayPickAction *action)

  Static Public Member Functions
static SoType getClassTypeId (void)
static void initClass (void)

  Public Attributes
SoSFEnum wrapS
SoSFEnum wrapT
SoSFEnum model
SoSFColor blendColor
SoSFVec4f backgroundColor
SoSFVec2s size
SoSFNode scene
SoSFNode sceneTransparencyType
SoSFEnum transparencyFunction
SoSFEnum type

  Protected Member Functions
virtual const SoFieldData * getFieldData (void) const

  Static Protected Member Functions
static const SoFieldData ** getFieldDataPtr (void)

  Additional Inherited Members

Detailed Description

The SoSceneTexture2 class is used to create a 2D texture from a Coin scene graph.

Lets the rendering of a scene graph be specified as a texture image to be used in another scene graph. Set up the scene graph used for a texture in the SoSceneTexture2::scene field. This node behaves exactly like SoTexture2 when it comes mapping the actual texture onto subsequent geometry. Please read the SoTexture2 documentation for more information about how textures are mapped onto shapes.

A notable feature of this node is that it will use offscreen pbuffers for hardware accelerated rendering, if they are available from the OpenGL driver. WGL, GLX and AGL, for OpenGL drivers on Microsoft Windows, X11 and Mac OS X, respectively, all support the OpenGL Architecture Review Board (ARB) pbuffer extension in later incarnations from most OpenGL vendors.

Note also that the offscreen pbuffer will be used directly on the card as a texture, with no costly round trip back and forth from CPU memory, if the OpenGL driver supports the recent ARB_render_texture extension.

An important limitation is that textures should have dimensions that are equal to a whole power-of-two, see documentation for SoSceneTexture::size.

FILE FORMAT/DEFAULTS:

SceneTexture2 {
    size 256 256
    scene NULL
    sceneTransparencyType NULL
    type RGBA_UNSIGNED_BYTE
    backgroundColor 0 0 0 0
    transparencyFunction NONE
    wrapS REPEAT
    wrapT REPEAT
    model MODULATE
    blendColor 0 0 0
}

Since:
    Coin 2.2

Member Enumeration Documentation

  enum SoSceneTexture2::Model
Texture mapping model, for deciding how to 'merge' the texturemap with the object it is mapped onto.

Enumerator

MODULATE
    Texture color is multiplied by the polygon color. The result will be Phong shaded (if light model is PHONG).

DECAL
    Texture image overwrites polygon shading. Textured pixels will not be Phong shaded. Has undefined behaviour for grayscale and grayscale-alpha textures.

BLEND
    This model is normally used with monochrome textures (i.e. textures with one or two components). The first component, the intensity, is then used to blend between the shaded color of the polygon and the SoSceneTexture2::blendColor.

REPLACE
    Texture image overwrites polygon shading. Textured pixels will not be Phong shaded. Supports grayscale and grayscale alpha textures. This feature requires OpenGL 1.1. MODULATE will be used if OpenGL version < 1.1 is detected.

  enum SoSceneTexture2::Wrap
Enumeration of wrapping strategies which can be used when the texturemap doesn't cover the full extent of the geometry.

Enumerator

REPEAT
    Repeat texture when coordinate is not between 0 and 1.

CLAMP
    Clamp coordinate between 0 and 1.

  enum SoSceneTexture2::TransparencyFunction
For deciding how the texture's alpha channel is handled. It's not possible to automatically detect this, since the texture is stored only on the graphics card's memory, and it'd be too slow to fetch the image to test the alpha channel like Coin does for regular textures.

Enumerator

NONE
    The alpha channel is ignored.

ALPHA_BLEND
    Alpha blending is used.

ALPHA_TEST
    An alpha test function is used.

  enum SoSceneTexture2::Type

Enumerator

DEPTH
    Specifies a depth buffer texture.

RGBA8
    Specifies an RGBA texture with 8 bits per component.

Member Function Documentation

  SoType SoSceneTexture2::getTypeId (void) const [virtual]
Returns the type identification of an object derived from a class inheriting SoBase. This is used for run-time type checking and 'downward' casting.

Usage example:

void foo(SoNode * node)
{
  if (node->getTypeId() == SoFile::getClassTypeId()) {
    SoFile * filenode = (SoFile *)node;  // safe downward cast, knows the type
  }
}

For application programmers wanting to extend the library with new nodes, engines, nodekits, draggers or others: this method needs to be overridden in all subclasses. This is typically done as part of setting up the full type system for extension classes, which is usually accomplished by using the pre-defined macros available through for instance Inventor/nodes/SoSubNode.h (SO_NODE_INIT_CLASS and SO_NODE_CONSTRUCTOR for node classes), Inventor/engines/SoSubEngine.h (for engine classes) and so on.

For more information on writing Coin extensions, see the class documentation of the toplevel superclasses for the various class groups.

Implements SoBase.

  const SoFieldData * SoSceneTexture2::getFieldData (void) const [protected], [virtual]
Returns a pointer to the class-wide field data storage object for this instance. If no fields are present, returns NULL.

Reimplemented from SoFieldContainer.

  void SoSceneTexture2::notify (SoNotList * l) [virtual]
Notifies all auditors for this instance when changes are made.

Reimplemented from SoNode.

  void SoSceneTexture2::write (SoWriteAction * action) [virtual]
Action method for SoWriteAction.

Writes out a node object, and any connected nodes, engines etc, if necessary.

Reimplemented from SoNode.

  void SoSceneTexture2::doAction (SoAction * action) [virtual]
This function performs the typical operation of a node for any action.

Reimplemented from SoNode.

  void SoSceneTexture2::GLRender (SoGLRenderAction * action) [virtual]
Action method for the SoGLRenderAction.

This is called during rendering traversals. Nodes influencing the rendering state in any way or who wants to throw geometry primitives at OpenGL overrides this method.

Reimplemented from SoNode.

  void SoSceneTexture2::callback (SoCallbackAction * action) [virtual]
Action method for SoCallbackAction.

Simply updates the state according to how the node behaves for the render action, so the application programmer can use the SoCallbackAction for extracting information about the scene graph.

Reimplemented from SoNode.

  void SoSceneTexture2::rayPick (SoRayPickAction * action) [virtual]
Action method for SoRayPickAction.

Checks the ray specification of the action and tests for intersection with the data of the node.

Nodes influencing relevant state variables for how picking is done also overrides this method.

Reimplemented from SoNode.

Member Data Documentation

  SoSFEnum SoSceneTexture2::wrapS
Wrapping strategy for the S coordinate when the texturemap is narrower than the object to map onto.

Default value is SoSceneTexture2::REPEAT.

  SoSFEnum SoSceneTexture2::wrapT
Wrapping strategy for the T coordinate when the texturemap is shorter than the object to map onto.

Default value is SoSceneTexture2::REPEAT.

  SoSFEnum SoSceneTexture2::model
Texturemapping model for how the texturemap is 'merged' with the polygon primitives it is applied to. Default value is SoSceneTexture2::MODULATE.

  SoSFColor SoSceneTexture2::blendColor
Blend color. Used when SoSceneTexture2::model is SoSceneTexture2::BLEND.

Default color value is [0, 0, 0], black, which means no contribution to the blending is made.

  SoSFVec4f SoSceneTexture2::backgroundColor
The color the color buffer is cleared to before rendering the scene. Default value is (0.0f, 0.0f, 0.0f, 0.0f).

  SoSFVec2s SoSceneTexture2::size
The size of the texture.

This node currently only supports power of two textures. If the size is not a power of two, the value will be rounded upwards to the next power of two.

  SoSFNode SoSceneTexture2::scene
The scene graph that is rendered into the texture.

  SoSFNode SoSceneTexture2::sceneTransparencyType
Used for overriding the transparency type for the sub scene graph. Should contain an instance of the SoTransparecyType node, or NULL to inherit the transparency type from the current viewer.

Please note that if you want to render the texture using frame buffer objects, you need to use of of the NONE, SCREEN_DOOR, ADD or BLEND transparency types.

  SoSFEnum SoSceneTexture2::transparencyFunction
The transparency function used. Default value is NONE.

  SoSFNode SoSceneTexture2::type
The type of texture to generate. RGBA_UNSIGNED_BYTE for normal texture, DEPTH for a depth buffer texture, RGBA_FLOAT for a floating point RGBA texture. texture. Default is RGBA_UNSIGNED_BYTE.

Author

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