OGRE  2.0
Object-Oriented Graphics Rendering Engine
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Ogre::Volume::Source Class Referenceabstract

Abstract class defining the density function. More...

#include <OgreVolumeSource.h>

+ Inheritance diagram for Ogre::Volume::Source:

Public Member Functions

virtual ~Source (void)
 Destructor. More...
 
bool getFirstRayIntersection (const Ray &ray, Vector3 &result, Real scale=(Real) 1.0, size_t maxIterations=5000, Real maxDistance=(Real) 10000.0) const
 Gets the first intersection of a ray with the volume. More...
 
virtual Real getValue (const Vector3 &position) const =0
 Gets the density value at a specific position. More...
 
virtual Vector4 getValueAndGradient (const Vector3 &position) const =0
 Gets the density value and gradient at a specific position. More...
 
Real getVolumeSpaceToWorldSpaceFactor (void) const
 Gets a factor to come from volume coordinate to world coordinate. More...
 
void serialize (const Vector3 &from, const Vector3 &to, float voxelWidth, const String &file)
 Serializes a volume source to a discrete grid file with deflated compression. More...
 
void serialize (const Vector3 &from, const Vector3 &to, float voxelWidth, Real maxClampedAbsoluteDensity, const String &file)
 Same as the other serialize function but with a user definable maximum absolute density value. More...
 

Static Public Attributes

static const size_t SERIALIZATION_CHUNK_SIZE
 The amount of items being written as one chunk during serialization. More...
 
static const uint32 VOLUME_CHUNK_ID
 The id of volume files. More...
 
static const uint16 VOLUME_CHUNK_VERSION
 The version of volume files. More...
 

Protected Member Functions

virtual Vector3 getIntersectionEnd (const Ray &ray, Real maxDistance) const
 Gets the end vector of an intersection. More...
 
virtual Vector3 getIntersectionStart (const Ray &ray, Real maxDistance) const
 Gets the start vector of an intersection. More...
 

Detailed Description

Abstract class defining the density function.

Definition at line 39 of file OgreVolumeSource.h.

Constructor & Destructor Documentation

virtual Ogre::Volume::Source::~Source ( void  )
virtual

Destructor.

Member Function Documentation

bool Ogre::Volume::Source::getFirstRayIntersection ( const Ray ray,
Vector3 result,
Real  scale = (Real) 1.0,
size_t  maxIterations = 5000,
Real  maxDistance = (Real) 10000.0 
) const

Gets the first intersection of a ray with the volume.

If you are using this together with the VolumeChunk: Beware of the possible scaling or other transformations you did on the Chunk! Do the inverse first on the ray origin. Example of a scaling with the factor 10: ray.setOrigin(ray.getOrigin() / (Real)10.0);

Parameters
rayThe ray.
resultWill hold the intersection point if there is an intersection.
scaleThe scaling of the volume compared to the world.
maxIterationsThe maximum amount of iterations on the ray before giving up.
maxDistanceThe maximum distance of the intersection point.
virtual Vector3 Ogre::Volume::Source::getIntersectionEnd ( const Ray ray,
Real  maxDistance 
) const
protectedvirtual

Gets the end vector of an intersection.

This is needed for restricted volumes like discreet grids.

Parameters
rayThe ray of the intersection.
maxDistanceThe maximum distance to query the ray for intersections.
Returns
The end point of the intersection ray.

Reimplemented in Ogre::Volume::GridSource.

virtual Vector3 Ogre::Volume::Source::getIntersectionStart ( const Ray ray,
Real  maxDistance 
) const
protectedvirtual

Gets the start vector of an intersection.

This is needed for restricted volumes like discreet grids.

Parameters
rayThe ray of the intersection.
maxDistanceThe maximum distance to query the ray for intersections.
Returns
The start point of the intersection ray.

Reimplemented in Ogre::Volume::GridSource.

virtual Real Ogre::Volume::Source::getValue ( const Vector3 position) const
pure virtual
virtual Vector4 Ogre::Volume::Source::getValueAndGradient ( const Vector3 position) const
pure virtual

Gets the density value and gradient at a specific position.

Parameters
positionThe position.
Returns
A vector with x, y, z containing the gradient and w containing the density.

Implemented in Ogre::Volume::CSGNoiseSource, Ogre::Volume::CSGScaleSource, Ogre::Volume::CSGNegateSource, Ogre::Volume::CSGDifferenceSource, Ogre::Volume::CSGUnionSource, Ogre::Volume::CSGIntersectionSource, Ogre::Volume::CSGCubeSource, Ogre::Volume::GridSource, Ogre::Volume::CSGPlaneSource, Ogre::Volume::CacheSource, and Ogre::Volume::CSGSphereSource.

Real Ogre::Volume::Source::getVolumeSpaceToWorldSpaceFactor ( void  ) const

Gets a factor to come from volume coordinate to world coordinate.

Returns
The factor, 1.0 in the default implementation.
void Ogre::Volume::Source::serialize ( const Vector3 from,
const Vector3 to,
float  voxelWidth,
const String file 
)

Serializes a volume source to a discrete grid file with deflated compression.

To achieve better compression, all density values are clamped within a maximum absolute value of (to - from).length() / 16.0. The values are scanned in this inner-loop-order: z, x, y. y last because there is usually the least isosurface intersection to be expected in the use case of terrain and so more often the maximum density value hit. The values are written as 16 Bit floats to save space. Note that this process is not lossless, the tradeoff is between accuracy of the source-reproduction (smaller voxelWidth) and smaller filesize (bigger voxelWidth).

Parameters
fromThe start point to scan the volume.
toThe end point to scan the volume.
voxelWidthThe width of a single cube in the density grid.
fileThe file to write the grid to.
void Ogre::Volume::Source::serialize ( const Vector3 from,
const Vector3 to,
float  voxelWidth,
Real  maxClampedAbsoluteDensity,
const String file 
)

Same as the other serialize function but with a user definable maximum absolute density value.

Parameters
fromThe start point to scan the volume.
toThe end point to scan the volume.
voxelWidthThe width of a single cube in the density grid.
maxClampedAbsoluteDensityThe maximum absolute density value to be written into the file, influencing the compression rate.
fileThe file to write the grid to.

Member Data Documentation

const size_t Ogre::Volume::Source::SERIALIZATION_CHUNK_SIZE
static

The amount of items being written as one chunk during serialization.

Definition at line 74 of file OgreVolumeSource.h.

const uint32 Ogre::Volume::Source::VOLUME_CHUNK_ID
static

The id of volume files.

Definition at line 68 of file OgreVolumeSource.h.

const uint16 Ogre::Volume::Source::VOLUME_CHUNK_VERSION
static

The version of volume files.

Definition at line 71 of file OgreVolumeSource.h.


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