sobumpmap(3)

NAME

SoBumpMap

SYNOPSIS

#include <Inventor/nodes/SoBumpMap.h>
Inherits SoNode.

Detailed Description

The SoBumpMap class is used to map a bump map onto subsequent shapes.

SoBumpMap has support for two types of maps. If the image is a three component (RGB) image, it will be treated as a normal map, where the
red image component equals the X normal component, green equals Y, and blue is Z. See
http://www.paulsprojects.net/tutorials/simplebump/simplebump.html for a nice introduction about bump mapping and normal maps.

If the image is a grayscale image, it will be treated as a height map, and automatically converted to a normal map.

For bump mapping to work with extension nodes for Coin, the
SoShape::generatePrimitives() method must be correctly implemented for the shape. This is needed since tangent space coordinates needs to be
calculated for each vertex in the shape. All shape nodes which are a
standard part of Coin meets this criteria.

Bump mapping in Coin requires OpenGL 1.3, or the following OpenGL
extensions: GL_ARB_multitexture, GL_ARB_texture_cube_map,
GL_ARB_texture_env_combine and GL_ARB_texture_env_dot3 (or the
corresponding EXT extensions). If the run-time system doesn't meet
these requirements, Coin will post a warning and the bump map will
simply be ignored.

GL_ARB_vertex_program and GL_ARB_fragment_program is required to get
specular lighting on the bumps. If these extensions are not available, the bumps will be rendered with diffuse lighting only.

Bump mapped objects will be rendered with multiple rendering passes.
One extra pass per light source for diffuse only bumps, and two extra
passes per light source for diffuse and specular bumps. You can turn
off specular lighting on the bumps by setting specularColor to (0.0,
0.0, 0.0).

FILE FORMAT/DEFAULTS:

BumpMap {

filename ''
image 0 0 0

wrapS REPEAT
wrapT REPEAT

}

Since:

Coin 2.2

Public Types

enum Wrap { REPEAT = SoTextureImageElement::REPEAT, CLAMP =

SoTextureImageElement::CLAMP }

Public Member Functions

virtual SoType getTypeId (void) const
SoBumpMap (void)
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)
static SbBool readImage (const SbString &fname, int &w, int &h, int

&nc, unsigned char *&bytes)

Public Attributes

SoSFString filename
SoSFImage image
SoSFEnum wrapS
SoSFEnum wrapT

Protected Member Functions

virtual const SoFieldData * getFieldData (void) const virtual ~SoBumpMap ()
virtual SbBool readInstance (SoInput *in, unsigned short flags) virtual void notify (SoNotList *list)

Static Protected Member Functions

static const SoFieldData ** getFieldDataPtr (void)

Member Enumeration Documentation

enum SoBumpMap::Wrap

Enumeration of wrapping strategies which can be used when the bump map doesn't cover the full extent of the geometry.

Enumerator:

REPEAT Repeat bump map when coordinate is not between 0 and 1.

CLAMP Clamp coordinate between 0 and 1.

Constructor & Destructor Documentation

SoBumpMap::SoBumpMap (void)

Constructor.

SoBumpMap::~SoBumpMap () [protected, virtual]

Destructor. Frees up internal resources used to store texture image
data.

Member Function Documentation

SoType SoBumpMap::getClassTypeId (void) [static]

This static method returns the SoType object associated with objects of this class.

Reimplemented from SoNode.

SoType SoBumpMap::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

}
else if (node->getTypeId().isOfType(SoGroup::getClassTypeId())) {

SoGroup * group = (SoGroup *)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 ** SoBumpMap::getFieldDataPtr (void) [static, protected]

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

Reimplemented from SoNode.

const SoFieldData * SoBumpMap::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 SoBumpMap::initClass (void) [static]

Sets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system.

Reimplemented from SoNode.

Referenced by SoNode::initClasses().

void SoBumpMap::doAction (SoAction * action) [virtual]

This function performs the typical operation of a node for any action.

Reimplemented from SoNode.

Referenced by callback().

void SoBumpMap::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.

References SoSFEnum::getValue(), SoSFImage::getValue(), image, wrapS,
and wrapT.

void SoBumpMap::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.

References doAction().

void SoBumpMap::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.

References filename, SoNotList::getLastField(), image, and
SoField::setDefault().

SbBool SoBumpMap::readImage (const SbString & fname, int & w, int & h, int

& nc, unsigned char *& bytes) [static] Not implemented. Was added to the API by mistake. Will be removed in
Coin 3.

SbBool SoBumpMap::readInstance (SoInput * in, unsigned short flags)

[protected, virtual]
This method is mainly intended for internal use during file import
operations.

It reads a definition of an instance from the input stream in. The input stream state points to the start of a serialized / persistant
representation of an instance of this class type.

TRUE or FALSE is returned, depending on if the instantiation and
configuration of the new object of this class type went ok or not. The import process should be robust and handle corrupted input streams by
returning FALSE.

flags is used internally during binary import when reading user extension nodes, group nodes or engines.

Reimplemented from SoNode.

void SoBumpMap::notify (SoNotList * l) [protected, virtual]

Notifies all auditors for this instance when changes are made.

Reimplemented from SoNode.

Member Data Documentation

SoSFString SoBumpMap::filename

Bump map (or normal map) filename, referring to a file on disk in a
supported image bitmap format. See SoBumpMap::filename for more information.

Referenced by rayPick().

SoSFImage SoBumpMap::image

Inline image data. Defaults to contain an empty bump map.

Referenced by GLRender(), and rayPick().

SoSFEnum SoBumpMap::wrapS

Wrapping strategy for the S coordinate when the bump map is narrower
than the object to map onto.

Default value is SoBumpMap::REPEAT.

Referenced by GLRender().

SoSFEnum SoBumpMap::wrapT

Wrapping strategy for the T coordinate when the bump map is shorter
than the object to map onto.

Default value is SoBumpMap::REPEAT.

Referenced by GLRender().

Author

Generated automatically by Doxygen for Coin from the source code.

Version 2.5.0 28 Jun 2008 SoBumpMap(3)