Ogre::ProgressiveMesh Class Reference

This class reduces the complexity of the geometry it is given. More...

#include <OgreProgressiveMesh.h>

List of all members.

Public Types

typedef std::vector< IndexData * > LODFaceList

enum VertexReductionQuota { VRQ_CONSTANT, VRQ_PROPORTIONAL }

The way to derive the quota of vertices which are reduced at each LOD. More...

Public Member Functions

ProgressiveMesh (const VertexData *vertexData, const IndexData *indexData)

Constructor, takes the geometry data and index buffer.

virtual ~ProgressiveMesh ()

virtual void addExtraVertexPositionBuffer (const VertexData *vertexData)

Adds an extra vertex position buffer.

virtual void build (ushort numLevels, LODFaceList *outList, VertexReductionQuota quota=VRQ_PROPORTIONAL, Real reductionValue=0.5f)

Builds the progressive mesh with the specified number of levels.

Protected Types

typedef std::vector< PMTriangle > TriangleList

typedef std::vector< PMFaceVertex > FaceVertexList

typedef std::vector< PMVertex > CommonVertexList

typedef std::vector< Real > WorstCostList

typedef std::vector< PMWorkingData > WorkingDataList

Protected Member Functions

void addWorkingData (const VertexData *vertexData, const IndexData *indexData)

Internal method for building PMWorkingData from geometry data.

void initialiseEdgeCollapseCosts (void)

Internal method for initialising the edge collapse costs.

Real computeEdgeCollapseCost (PMVertex *src, PMVertex *dest)

Internal calculation method for deriving a collapse cost from u to v.

Real computeEdgeCostAtVertexForBuffer (WorkingDataList::iterator idata, size_t vertIndex)

Internal method evaluates all collapse costs from this vertex and picks the lowest for a single buffer.

void computeEdgeCostAtVertex (size_t vertIndex)

Internal method evaluates all collapse costs from this vertex for every buffer and returns the worst.

void computeAllCosts (void)

Internal method to compute edge collapse costs for all buffers /.

size_t getNextCollapser (void)

Internal method for getting the index of next best vertex to collapse.

void bakeNewLOD (IndexData *pData)

Internal method builds an new LOD based on the current state.

void collapse (PMVertex *collapser)

Internal method, collapses vertex onto it's saved collapse target.

void dumpContents (const String &log)

Internal debugging method.

Protected Attributes

const VertexData * mpVertexData

const IndexData * mpIndexData

size_t mCurrNumIndexes

size_t mNumCommonVertices

WorkingDataList mWorkingData

Multiple copies, 1 per vertex buffer.

WorstCostList mWorstCosts

The worst collapse cost from all vertex buffers for each vertex.

Detailed Description

This class reduces the complexity of the geometry it is given.

This class is dedicated to reducing the number of triangles in a given mesh taking into account seams in both geometry and texture co-ordinates and meshes which have multiple frames.

: The primary use for this is generating LOD versions of Mesh objects, but it can be used by any geometry provider. The only limitation at the moment is that the provider uses a common vertex buffer for all LODs and one index buffer per LOD. Therefore at the moment this class can only handle indexed geometry.

: NB the interface of this class will certainly change when compiled vertex buffers are supported.

Definition at line 55 of file OgreProgressiveMesh.h.

Member Typedef Documentation

typedef std::vector<PMVertex> Ogre::ProgressiveMesh::CommonVertexList [protected]

Definition at line 183 of file OgreProgressiveMesh.h.

typedef std::vector<PMFaceVertex> Ogre::ProgressiveMesh::FaceVertexList [protected]

Definition at line 182 of file OgreProgressiveMesh.h.

typedef std::vector<IndexData*> Ogre::ProgressiveMesh::LODFaceList

Definition at line 68 of file OgreProgressiveMesh.h.

typedef std::vector<PMTriangle> Ogre::ProgressiveMesh::TriangleList [protected]

Definition at line 181 of file OgreProgressiveMesh.h.

typedef std::vector<PMWorkingData> Ogre::ProgressiveMesh::WorkingDataList [protected]

Definition at line 194 of file OgreProgressiveMesh.h.

typedef std::vector<Real> Ogre::ProgressiveMesh::WorstCostList [protected]

Definition at line 184 of file OgreProgressiveMesh.h.

Member Enumeration Documentation

enum Ogre::ProgressiveMesh::VertexReductionQuota

The way to derive the quota of vertices which are reduced at each LOD.

Enumeration values:

VRQ_CONSTANT A set number of vertices are removed at each reduction.

VRQ_PROPORTIONAL A proportion of the remaining number of vertices are removed at each reduction.

Definition at line 60 of file OgreProgressiveMesh.h.

Constructor & Destructor Documentation

Ogre::ProgressiveMesh::ProgressiveMesh ( const VertexData * vertexData,

const IndexData * indexData

)

Constructor, takes the geometry data and index buffer.

Remarks:
DO NOT pass write-only, unshadowed buffers to this method! They will not work. Pass only shadowed buffers, or better yet perform mesh reduction as an offline process using DefaultHardwareBufferManager to manage vertex buffers in system memory.

virtual Ogre::ProgressiveMesh::~ProgressiveMesh ( ) [virtual]

Member Function Documentation

virtual void Ogre::ProgressiveMesh::addExtraVertexPositionBuffer ( const VertexData * vertexData ) [virtual]

Adds an extra vertex position buffer.

Remarks:
As well as the main vertex buffer, the client of this class may add extra versions of the vertex buffer which will also be taken into account when the cost of simplifying the mesh is taken into account. This is because the cost of simplifying an animated mesh cannot be calculated from just the reference position, multiple positions needs to be assessed in order to find the best simplification option.

DO NOT pass write-only, unshadowed buffers to this method! They will not work. Pass only shadowed buffers, or better yet perform mesh reduction as an offline process using DefaultHardwareBufferManager to manage vertex buffers in system memory.

Parameters:

buffer Pointer to x/y/z buffer with vertex positions. The number of vertices must be the same as in the original GeometryData passed to the constructor.

void Ogre::ProgressiveMesh::addWorkingData ( const VertexData * vertexData,

const IndexData * indexData

) [protected]

Internal method for building PMWorkingData from geometry data.

void Ogre::ProgressiveMesh::bakeNewLOD ( IndexData * pData ) [protected]

Internal method builds an new LOD based on the current state.

virtual void Ogre::ProgressiveMesh::build ( ushort numLevels,

LODFaceList * outList,

VertexReductionQuota quota = VRQ_PROPORTIONAL,

Real reductionValue = 0.5f

) [virtual]

Builds the progressive mesh with the specified number of levels.

Parameters:

numLevels The number of levels to include in the output excluding the full detail version.

outList Pointer to a list of LOD geometry data which will be completed by the application. Each entry is a reduced form of the mesh, in decreasing order of detail.

quota The way to derive the number of vertices removed at each LOD

reductionValue Either the proportion of vertices to remove at each level, or a fixed number of vertices to remove at each level, depending on the value of quota

void Ogre::ProgressiveMesh::collapse ( PMVertex * collapser ) [protected]

Internal method, collapses vertex onto it's saved collapse target.

Remarks:
This updates the working triangle list to drop a triangle and recalculates the edge collapse costs around the collapse target. This also updates all the working vertex lists for the relevant buffer.

void Ogre::ProgressiveMesh::computeAllCosts ( void ) [protected]

Internal method to compute edge collapse costs for all buffers /.

Real Ogre::ProgressiveMesh::computeEdgeCollapseCost ( PMVertex * src,

PMVertex * dest

) [protected]

Internal calculation method for deriving a collapse cost from u to v.

void Ogre::ProgressiveMesh::computeEdgeCostAtVertex ( size_t vertIndex ) [protected]

Internal method evaluates all collapse costs from this vertex for every buffer and returns the worst.

Real Ogre::ProgressiveMesh::computeEdgeCostAtVertexForBuffer ( WorkingDataList::iterator idata,

size_t vertIndex

) [protected]

Internal method evaluates all collapse costs from this vertex and picks the lowest for a single buffer.

void Ogre::ProgressiveMesh::dumpContents ( const String & log ) [protected]

Internal debugging method.

size_t Ogre::ProgressiveMesh::getNextCollapser ( void ) [protected]

Internal method for getting the index of next best vertex to collapse.

void Ogre::ProgressiveMesh::initialiseEdgeCollapseCosts ( void ) [protected]

Internal method for initialising the edge collapse costs.

Member Data Documentation

size_t Ogre::ProgressiveMesh::mCurrNumIndexes [protected]

Definition at line 112 of file OgreProgressiveMesh.h.

size_t Ogre::ProgressiveMesh::mNumCommonVertices [protected]

Definition at line 113 of file OgreProgressiveMesh.h.

const IndexData* Ogre::ProgressiveMesh::mpIndexData [protected]

Definition at line 110 of file OgreProgressiveMesh.h.

const VertexData* Ogre::ProgressiveMesh::mpVertexData [protected]

Definition at line 109 of file OgreProgressiveMesh.h.

WorkingDataList Ogre::ProgressiveMesh::mWorkingData [protected]

Multiple copies, 1 per vertex buffer.

Definition at line 196 of file OgreProgressiveMesh.h.

WorstCostList Ogre::ProgressiveMesh::mWorstCosts [protected]

The worst collapse cost from all vertex buffers for each vertex.

Definition at line 199 of file OgreProgressiveMesh.h.

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

OgreProgressiveMesh.h


Public Types
typedef std::vector< IndexData * >	LODFaceList
enum	VertexReductionQuota { VRQ_CONSTANT, VRQ_PROPORTIONAL }
	The way to derive the quota of vertices which are reduced at each LOD. More...
Public Member Functions
	ProgressiveMesh (const VertexData vertexData, const IndexData indexData)
	Constructor, takes the geometry data and index buffer.
virtual	~ProgressiveMesh ()
virtual void	addExtraVertexPositionBuffer (const VertexData *vertexData)
	Adds an extra vertex position buffer.
virtual void	build (ushort numLevels, LODFaceList *outList, VertexReductionQuota quota=VRQ_PROPORTIONAL, Real reductionValue=0.5f)
	Builds the progressive mesh with the specified number of levels.
Protected Types
typedef std::vector< PMTriangle >	TriangleList
typedef std::vector< PMFaceVertex >	FaceVertexList
typedef std::vector< PMVertex >	CommonVertexList
typedef std::vector< Real >	WorstCostList
typedef std::vector< PMWorkingData >	WorkingDataList
Protected Member Functions
void	addWorkingData (const VertexData vertexData, const IndexData indexData)
	Internal method for building PMWorkingData from geometry data.
void	initialiseEdgeCollapseCosts (void)
	Internal method for initialising the edge collapse costs.
Real	computeEdgeCollapseCost (PMVertex src, PMVertex dest)
	Internal calculation method for deriving a collapse cost from u to v.
Real	computeEdgeCostAtVertexForBuffer (WorkingDataList::iterator idata, size_t vertIndex)
	Internal method evaluates all collapse costs from this vertex and picks the lowest for a single buffer.
void	computeEdgeCostAtVertex (size_t vertIndex)
	Internal method evaluates all collapse costs from this vertex for every buffer and returns the worst.
void	computeAllCosts (void)
	Internal method to compute edge collapse costs for all buffers /.
size_t	getNextCollapser (void)
	Internal method for getting the index of next best vertex to collapse.
void	bakeNewLOD (IndexData *pData)
	Internal method builds an new LOD based on the current state.
void	collapse (PMVertex *collapser)
	Internal method, collapses vertex onto it's saved collapse target.
void	dumpContents (const String &log)
	Internal debugging method.
Protected Attributes
const VertexData *	mpVertexData
const IndexData *	mpIndexData
size_t	mCurrNumIndexes
size_t	mNumCommonVertices
WorkingDataList	mWorkingData
	Multiple copies, 1 per vertex buffer.
WorstCostList	mWorstCosts
	The worst collapse cost from all vertex buffers for each vertex.