SoTVizRender Class Reference
[TerrainViz]

TerrainViz Renders the terrain. More...

#include <TerrainViz/nodes/SoTVizRender.h>

Inheritance diagram for SoTVizRender:
SoShape SoNode SoFieldContainer SoBase SoRefCounter SoTypedObject

List of all members.

Public Types

enum  MappingMode {
  TVIZ_TEXTURES = 0,
  TVIZ_COLORSCALE
}
enum  NormalQuality {
  TVIZ_32BIT_NORMALS = 0,
  TVIZ_64BIT_NORMALS
}
enum  CopyPolicy {
  COPY = 0,
  NO_COPY = 1,
  NO_COPY_AND_DELETE = 2
}

Public Member Functions

virtual SoType getTypeId () const
 SoTVizRender ()
SbBool loadFromXML (const FILE *fd)
SbBool loadFromXML (const char *fileName)
void setData (const SbTVizData *data, CopyPolicy cp=SoTVizRender::NO_COPY)
const SbTVizData * getData () const
void setTextureList (const SbTVizTextureList *texList, CopyPolicy cp=SoTVizRender::NO_COPY)
const SbTVizTextureList * getTextureList () const
void setColorScale (const SbTVizColorScale *colorScale, CopyPolicy cp=SoTVizRender::NO_COPY)
const SbTVizColorScale * getColorScale () const
SbBool writeToXML (const SbString &fileName)
SbBool writeToXML (const char *fileName)
void showTarget (SbBool state)

Static Public Member Functions

static SoType getClassTypeId ()

Public Attributes

SoSFNode camera
SoSFInt32 maxRenderedTriangles
SoSFEnum mappingMode
SoSFBool frustumCulling
SoSFBool normals
SoSFEnum normalQuality

Deprecated



SoDEPRECATED SoSFFloat triangleSizeAttenuation
SoDEPRECATED SoSFFloat distanceAttenuation

Detailed Description

TerrainViz Renders the terrain.

The TerrainViz extension allows terrain visualization using an auto-adaptive mesh technique and a quadtree of textures. It uses a multi-resolution technique that re-meshes the terrain at every frame with a constant number of triangles. The local mesh accuracy depends on the point of view and the altitude gradient. The texture level depends on the point of view only.

TerrainViz attempts to render the terrain at a constant frame rate.

Controls are provided for adjusting quality versus performance.

SoTVizRender is the shape node of TerrainViz. It re-computes the mesh at every frame.

Normals are enabled/disabled by the normals field. By default they are enabled. Until TerrainViz V2.0, normals were activated in the terrain model when the creaseAngle of the current SoShapeHints was different from 0. For compatibility with this older behavior, use environment variable TVIZ_COMPAT_20 (see also SoPreferences).

Normals are memory consuming. If enabled, normals are pre-computed. The memory used by pre-computed normals is not freed until a new SbTVizData is supplied in order not to slow down the frame rate when changing and changing again the normals field value.

The terrain can be mapped with a texture tree using an SbTVizTextureList node, or with color mapping using an SbTVizColorScale node (color changes depending on altitude).

All values are expressed as modeling coordinates.

Data (terrain altitudes and textures) can be provided two different ways:

The mesh computation is controlled by several fields.

NOTE: SoTVizRender is not meant to be exported as an .iv file because it uses SbTVizData/SbTVizTextureList/SbTVizTexture instances containing the data (elevations, textures). The way to save a terrain scene is to export it to an XML file referencing an elevation data file and image files for textures. Use writeToXML to export your scene and loadFromXML to retrieve it.

XML FILE FORMAT

< !-- TGS TerrainViz X.X --> File header with TerrainViz version in XML comment format.

<TerrainViz>                                                     Begins the file.

<data> Begins the data block.

<format> <value> </format>
Ex: <format> "REGULARGRID" </format> 		Specificies the format. Can be "REGULARGRID" (data is organized in a 2D array). Default: "REGULARGRID".

<fileName> <value> </fileName>
Ex: <fileName> "elevation.dat" </fileName> 		Data file name between "".

<step> <value> </step>
Ex: <step> (2.5E-4, 2.5E-4, 2.5E-4) </step> 		Sample size along the three dimensions.

<realOffset> <value> </realOffset>
Ex: <realOffset> (0., 0., 0.) </realOffset> 		Offset of the terrain. The terrain starts at (x=0, y=0, z(0, 0)) by default. Default (0., 0., 0.).

<encoding> <value> </encoding>
Ex: <encoding> "BIG_ENDIAN" </encoding> 		Can be "LITTLE_ENDIAN" or "BIG_ENDIAN". UNIX systems are generally big endian whereas Intel systems are usually little endian. This field must refer to the system encoding where the binary file was created (necessary for binary files).

<openMode> <value> </openMode>
Ex: <openMode> "BINARY" </openMode> 		Can be "ASCII" or "BINARY". Tells if the file is binary or ASCII. In the binary case, the encoding field is necessary.

<type> <value> </type>
Ex: <type> "UCHAR" </type> 		Gives the data type (unsigned char, unsigned short, or float). Can be "UCHAR", "USHORT", "UINT", "FLOAT", "CHAR", "SHORT", "INT".

</data> Ends the data block.

<texture> Begins the texture block.

<fileName> <value> </fileName>
Ex: <fileName> "tex00.jpg" </fileName> 		Texture file name between "".

<level> <value> </level>
Ex: <level> 0 </level> 		Level of the texture. This is the level of the quadtree in which this texture appears. Levels start at 0.

<position> <value> </position>
Ex: <position> (0, 0) </position> 		Position of the texture. This is the position of the texture inside the level. Can be omitted if level is zero.

</texture> Ends the texture block.

</TerrainViz> Ends the file.

NOTE: Blocks are order independent. Fields within the parent block are order independent too. There should be one data block and zero or more texture blocks.

FILE FORMAT/DEFAULT

SEE ALSO

SbTVizData, SbTVizRegularGridData, SbTVizTexture, SbTVizTextureList, SoTViz

Deprecated:

Deprecated since Open Inventor 9500
No longer supported.

Member Enumeration Documentation

enum SoTVizRender::CopyPolicy
Enumerator:
COPY 

TerrainViz will make a copy of the data.

NO_COPY 

Passed buffer used, user will delete (default).

NO_COPY_AND_DELETE 

Passed buffer used, SoTVizRender will delete.

enum SoTVizRender::MappingMode
Enumerator:
TVIZ_TEXTURES 

Mapping uses the textures.

TVIZ_COLORSCALE 

Mapping uses the color scale.

enum SoTVizRender::NormalQuality
Enumerator:
TVIZ_32BIT_NORMALS 

Pre-computed normals are packed as 32-bit values.

TVIZ_64BIT_NORMALS 

Pre-computed normals are packed as 64-bit values.

Constructor & Destructor Documentation

SoTVizRender::SoTVizRender (  ) 

Constructor.

Member Function Documentation

static SoType SoTVizRender::getClassTypeId (  )  [static]

Returns the type identifier for this class.

Reimplemented from SoShape.

const SbTVizColorScale* SoTVizRender::getColorScale (  )  const

Returns the color scale for contouring/shading.

const SbTVizData* SoTVizRender::getData (  )  const

Returns the elevation data.

const SbTVizTextureList* SoTVizRender::getTextureList (  )  const

Returns the texture list.

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

Returns the type identifier for this specific instance.

Reimplemented from SoShape.

SbBool SoTVizRender::loadFromXML ( const char *  fileName  ) 

Loads a TerrainViz description file (XML) and initializes the members SbTVizData and SbTVizTextureList.

Returns TRUE if loaded successfully, FALSE otherwise.

SbBool SoTVizRender::loadFromXML ( const FILE *  fd  ) 

Loads a TerrainViz description file (XML) and initializes the members SbTVizData and SbTVizTextureList.

Returns TRUE if loaded successfully, FALSE otherwise.

NOTE: In this case, files referenced in this XML file (elevation & textures) must be specified with an absolute path as the path of the XML file is unknown.

void SoTVizRender::setColorScale ( const SbTVizColorScale *  colorScale,
CopyPolicy  cp = SoTVizRender::NO_COPY 
)

Sets the color scale for contouring/shading.

If TVIZ_COMPAT_20 is defined, the copy policy default is NO_COPY_AND_DELETE.

void SoTVizRender::setData ( const SbTVizData *  data,
CopyPolicy  cp = SoTVizRender::NO_COPY 
)

Sets the elevation data.

If TVIZ_COMPAT_20 is defined, the copy policy default is NO_COPY_AND_DELETE.

void SoTVizRender::setTextureList ( const SbTVizTextureList *  texList,
CopyPolicy  cp = SoTVizRender::NO_COPY 
)

Sets the texture list.

If TVIZ_COMPAT_20 is defined, the copy policy default is NO_COPY_AND_DELETE.

void SoTVizRender::showTarget ( SbBool  state  ) 

Displays the look-at vector.

SbBool SoTVizRender::writeToXML ( const char *  fileName  ) 

Writes the node description (elevation and textures) in a TerrainViz file as shown above.

SbBool SoTVizRender::writeToXML ( const SbString &  fileName  ) 

Writes the node description (elevation and textures) in a TerrainViz file as shown above.

Member Data Documentation

SoSFNode SoTVizRender::camera

Specifies the camera to be used for real-time mesh processing.

If NULL, the current camera is used.

SoDEPRECATED SoSFFloat SoTVizRender::distanceAttenuation

This field allows the user to decrease the number of triangles displayed as the camera gets further from the terrain.

If s is the largest dimension of the terrain, and d is the distance between the camera and the terrain, and

SoSFBool SoTVizRender::frustumCulling

Enables frustum culling so that the invisible parts of the terrain are not rendered.

SoSFEnum SoTVizRender::mappingMode

Mapping mode.

Two modes are available:

SoSFInt32 SoTVizRender::maxRenderedTriangles

Specifies the maximum number of rendered triangles.

The number of triangles displayed can be decreased using the distanceAttenuation field.

SoSFEnum SoTVizRender::normalQuality

Sets the normal quality.

Default value is: TVIZ_32BIT_NORMALS If the lighting of the terrain has black areas, you can increase the normal precision (e.g., specify TVIZ_64BIT_NORMALS) to remove this artifact.

SoSFBool SoTVizRender::normals

Enables/disables the normals at each vertex.

Default is TRUE.

SoDEPRECATED SoSFFloat SoTVizRender::triangleSizeAttenuation

Specifies the value used in the function 1/distance^triangleSizeAttenuation which specifies the triangle size variation according to the distance.

In other words, this field adjusts the mesh density. Larger values cause the triangle size to increase more rapidly (or conversely, the mesh density decreases more rapidly).

Deprecated:

Deprecated since Open Inventor 6000
This field should not be used anymore.
The documentation for this class was generated from the following file:
Open Inventor Toolkit reference manual, generated on 12 Feb 2024
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