SoAppearancePreserver Class Reference
[FXViz]

Encapsulates an appearance preserving simplification algorithm. More...

#include <FXViz/APS/SoAppearancePreserver.h>

List of all members.

Public Types
typedef void	SoAppearancePreserverProgressCB (void *userData, SoAppearancePreserver *aps, int percent)
Public Member Functions
	SoAppearancePreserver ()
	~SoAppearancePreserver ()
void	setSceneGraphs (SoNode *original, SoNode *simplified)
void	setTextureSize (int width, int height)
void	setTriangleMinSize (int size)
void	setProgressCallback (SoAppearancePreserverProgressCB *cb, void *data=NULL)
SoNONUNICODE SoTexture2 *	getNormalMapTexture (const char *filename=NULL)
SoTexture2 *	getNormalMapTexture (const SbString &filename="")
SoNONUNICODE SoTexture2 *	getDisplacementMapTexture (const char *filename=NULL)
SoTexture2 *	getDisplacementMapTexture (const SbString &filename="")
SoTextureCoordinate2 *	getBumpCoords ()

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Detailed Description

Encapsulates an appearance preserving simplification algorithm.

This technique computes, from a highly detailed model and its corresponding simplified model obtained with the decimation tools (see SoSimplifyAction, SoSimplify...), a normal map texture and texture coordinates for this texture to be applied to the simplified model. For each triangle in the simplified model, there is a triangular area in the normal map texture that contains normal vectors derived from the original complex model. Using the bump mapping technique with the generated normal map, the rendering of the simplified model will appear with the details of the original model but using much fewer triangles.

Note 1: The time for generating the normal map depends on the size of the original model, the size of the simplified model, and also the size of the normal map texture. This process could take several minutes.

Note 2: The quality of the final rendering using the bump mapping technique is closely linked to the size of the normal map texture.

Limitations: The size of the normal map texture limits the number of possible triangles for the simplified model. This is because the minimum size for a triangle in the normal map texture is at least 3 pixels. So for a 256*256 texture size, a maximum of 22,000 triangles can be stored. If necessary, specify a larger texture (see setTextureSize) or a more aggressive simplification of the model.

SEE ALSO

SoBumpMappingProperty, SoTextureUnit.

Deprecated:

Deprecated since Open Inventor 9400
No longer supported.

See related examples:

BumpMapping

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Member Typedef Documentation

typedef void SoAppearancePreserver::SoAppearancePreserverProgressCB(void *userData, SoAppearancePreserver *aps, int percent)

Progress callback prototype.

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Constructor & Destructor Documentation

SoAppearancePreserver::SoAppearancePreserver

(

)

Constructor.

SoAppearancePreserver::~SoAppearancePreserver

(

)

Destructor.

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Member Function Documentation

SoTextureCoordinate2* SoAppearancePreserver::getBumpCoords

(

)

Computes the texture coordinates and creates an SoTextureCoordinate2 node.

The texture coordinates are stored in the texture coordinate point field. They can be applied with the bump mapping technique to the simplified model. NULL is returned if the texture coordinates could not be computed, generally due to there being more triangles than could be stored in the normal map.

SoTexture2* SoAppearancePreserver::getDisplacementMapTexture

(

const SbString &

filename = ""

)

Computes the displacement map texture and creates an SoTexture2 node.

If no file name is specified, the texture is stored in the SoTexture2 image field. Otherwise the file name is stored in the SoTexture2 filename field and the texture is written to a PNG format file. NULL is returned if the texture could not be computed, generally due to there being more triangles than could be stored in the normal map.

SoNONUNICODE SoTexture2* SoAppearancePreserver::getDisplacementMapTexture

(

const char *

filename = NULL

)

Computes the displacement map texture and creates an SoTexture2 node.

If no file name is specified, the texture is stored in the SoTexture2 image field. Otherwise the file name is stored in the SoTexture2 filename field and the texture is written to a PNG format file. NULL is returned if the texture could not be computed, generally due to there being more triangles than could be stored in the normal map.

Non Unicode List:

This function should not be used in a Unicode application.

SoTexture2* SoAppearancePreserver::getNormalMapTexture

(

const SbString &

filename = ""

)

Computes the normal map texture and creates an SoTexture2 node.

If no file name is specified, the texture is stored in the SoTexture2 image field. Otherwise the file name is stored in the SoTexture2 filename field and the texture is written to a PNG format file. NULL is returned if the texture could not be computed, generally due to there being more triangles than could be stored in the normal map.

SoNONUNICODE SoTexture2* SoAppearancePreserver::getNormalMapTexture

(

const char *

filename = NULL

)

Computes the normal map texture and creates an SoTexture2 node.

If no file name is specified, the texture is stored in the SoTexture2 image field. Otherwise the file name is stored in the SoTexture2 filename field and the texture is written to a PNG format file. NULL is returned if the texture could not be computed, generally due to there being more triangles than could be stored in the normal map.

Non Unicode List:

This function should not be used in a Unicode application.

void SoAppearancePreserver::setProgressCallback	(	SoAppearancePreserverProgressCB *	cb,
		void *	data = NULL
	)

Sets a progress callback.

This callback will be called at each percentage of completion, e.g., 1%, 2%...

void SoAppearancePreserver::setSceneGraphs	(	SoNode *	original,
		SoNode *	simplified
	)

Specifies the original scene graph and the simplified scene graph.

void SoAppearancePreserver::setTextureSize	(	int	width,
		int	height
	)

Specifies the texture size to be generated.

If the specified dimensions are not powers of two, the nearest powers of two will be used. Default size is 256 * 256 texels.

void SoAppearancePreserver::setTriangleMinSize

(

int

size

)

Specifies the mininum size for a triangle stored within the normal map texture.

Default size is 4 texels.

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

• FXViz/APS/SoAppearancePreserver.h