org.apache.commons.geometry.io.euclidean.threed.obj

Class ObjWriter

java.lang.Object

org.apache.commons.geometry.io.core.utils.AbstractTextFormatWriter

org.apache.commons.geometry.io.euclidean.threed.obj.ObjWriter

All Implemented Interfaces:

Closeable, AutoCloseable

public final class ObjWriter
extends AbstractTextFormatWriter

Class for writing OBJ files containing 3D polygon geometries.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	ObjWriter.MeshBuffer Class used to produce OBJ mesh content from sequences of facets.

Constructor Summary

Constructors

Constructor and Description
ObjWriter(Writer writer) Create a new instance that writes output with the given writer.

Method Summary

Modifier and Type	Method and Description
int	getVertexCount() Get the number of vertices written to the output.
int	getVertexNormalCount() Get the number of vertex normals written to the output.
ObjWriter.MeshBuffer	meshBuffer() Create a new ObjWriter.MeshBuffer instance with an unlimited batch size, meaning that no vertex definitions are duplicated in the mesh output.
ObjWriter.MeshBuffer	meshBuffer(int batchSize) Create a new ObjWriter.MeshBuffer instance with the given batch size.
void	writeBoundaries(BoundarySource3D src) Write the boundaries present in the given boundary source using a ObjWriter.MeshBuffer with an unlimited size.
void	writeBoundaries(BoundarySource3D src, int batchSize) Write the boundaries present in the given boundary source using a ObjWriter.MeshBuffer with the given batchSize.
void	writeComment(String comment) Write an OBJ comment with the given value.
void	writeFace(int... vertexIndices) Write a face with the given 0-based vertex indices.
void	writeFace(int[] vertexIndices, int normalIndex) Write a face with the given 0-based vertex indices and 0-based normal index.
void	writeFace(int[] vertexIndices, int[] normalIndices) Write a face with the given vertex and normal indices.
void	writeGroupName(String groupName) Write a group name to the output.
void	writeMesh(Mesh<?> mesh) Write a mesh to the output.
void	writeObjectName(String objectName) Write an object name to the output.
int	writeVertex(Vector3D vertex) Write a vertex and return the 0-based index of the vertex in the output.
int	writeVertexNormal(Vector3D normal) Write a vertex normal and return the 0-based index of the normal in the output.

Methods inherited from class org.apache.commons.geometry.io.core.utils.AbstractTextFormatWriter

close, getDoubleFormat, getLineSeparator, getWriter, setDoubleFormat, setLineSeparator, write, write, write, write, writeNewLine

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ObjWriter

public ObjWriter(Writer writer)

Create a new instance that writes output with the given writer.

Parameters:

writer - writer used to write output

Method Detail

getVertexCount

public int getVertexCount()

Get the number of vertices written to the output.

Returns:

the number of vertices written to the output.

getVertexNormalCount

public int getVertexNormalCount()

Get the number of vertex normals written to the output.

Returns:

the number of vertex normals written to the output.

writeComment

public void writeComment(String comment)

Write an OBJ comment with the given value.

Parameters:

comment - comment to write

Throws:

UncheckedIOException - if an I/O error occurs

writeObjectName

public void writeObjectName(String objectName)

Write an object name to the output. This is metadata for the file and does not affect the geometry, although it may affect how the file content is read by other programs.

Parameters:

objectName - the name to write

Throws:

UncheckedIOException - if an I/O error occurs

writeGroupName

public void writeGroupName(String groupName)

Write a group name to the output. This is metadata for the file and does not affect the geometry, although it may affect how the file content is read by other programs.

Parameters:

groupName - the name to write

Throws:

UncheckedIOException - if an I/O error occurs

writeVertex

public int writeVertex(Vector3D vertex)

Write a vertex and return the 0-based index of the vertex in the output.

Parameters:

vertex - vertex to write

Returns:

0-based index of the written vertex

Throws:

UncheckedIOException - if an I/O error occurs

writeVertexNormal

public int writeVertexNormal(Vector3D normal)

Write a vertex normal and return the 0-based index of the normal in the output.

Parameters:

normal - normal to write

Returns:

0-based index of the written normal

Throws:

UncheckedIOException - if an I/O error occurs

writeFace

public void writeFace(int... vertexIndices)

Write a face with the given 0-based vertex indices.

Parameters:

vertexIndices - 0-based vertex indices for the face

Throws:

IllegalArgumentException - if fewer than 3 vertex indices are given

IndexOutOfBoundsException - if any vertex index is computed to be outside of the bounds of the elements written so far

UncheckedIOException - if an I/O error occurs

writeFace

public void writeFace(int[] vertexIndices,
                      int normalIndex)

Write a face with the given 0-based vertex indices and 0-based normal index. The normal index is applied to all face vertices.

Parameters:

vertexIndices - 0-based vertex indices

normalIndex - 0-based normal index

Throws:

IndexOutOfBoundsException - if any vertex or normal index is computed to be outside of the bounds of the elements written so far

UncheckedIOException - if an I/O error occurs

writeFace

public void writeFace(int[] vertexIndices,
                      int[] normalIndices)

Write a face with the given vertex and normal indices. Indices are 0-based. The normalIndices argument may be null, but if present, must contain the same number of indices as vertexIndices.

Parameters:

vertexIndices - 0-based vertex indices; may not be null

normalIndices - 0-based normal indices; may be null but if present must contain the same number of indices as vertexIndices

Throws:

IllegalArgumentException - if fewer than 3 vertex indices are given or normalIndices is not null but has a different length than vertexIndices

IndexOutOfBoundsException - if any vertex or normal index is computed to be outside of the bounds of the elements written so far

UncheckedIOException - if an I/O error occurs

writeBoundaries

public void writeBoundaries(BoundarySource3D src)

Write the boundaries present in the given boundary source using a ObjWriter.MeshBuffer with an unlimited size.

Parameters:

src - boundary source containing the boundaries to write to the output

Throws:

IllegalArgumentException - if any boundary in the argument is infinite

UncheckedIOException - if an I/O error occurs

See Also:

meshBuffer(int), writeMesh(Mesh)

writeBoundaries

public void writeBoundaries(BoundarySource3D src,
                            int batchSize)

Write the boundaries present in the given boundary source using a ObjWriter.MeshBuffer with the given batchSize.

Parameters:

src - boundary source containing the boundaries to write to the output

batchSize - batch size to use for the mesh buffer; pass -1 to use a buffer of unlimited size

Throws:

IllegalArgumentException - if any boundary in the argument is infinite

UncheckedIOException - if an I/O error occurs

See Also:

meshBuffer(int), writeMesh(Mesh)

writeMesh

public void writeMesh(Mesh<?> mesh)

Write a mesh to the output. All vertices and faces are written exactly as found. For example, if a vertex is duplicated in the argument, it will also be duplicated in the output.

Parameters:

mesh - the mesh to write

Throws:

UncheckedIOException - if an I/O error occurs

meshBuffer

public ObjWriter.MeshBuffer meshBuffer()

Create a new ObjWriter.MeshBuffer instance with an unlimited batch size, meaning that no vertex definitions are duplicated in the mesh output. This produces the most compact mesh but at the most of higher memory usage during writing.

Returns:

new mesh buffer instance

meshBuffer

public ObjWriter.MeshBuffer meshBuffer(int batchSize)

Create a new ObjWriter.MeshBuffer instance with the given batch size. The batch size determines how many faces will be stored in the buffer before being flushed. Faces stored in the buffer share duplicate vertices, reducing the number of vertices required in the file. The batchSize is therefore a trade-off between higher memory usage (high batch size) and a higher probability of duplicate vertices present in the output (low batch size). A batch size of -1 indicates an unlimited batch size.

Parameters:

batchSize - number of faces to store in the buffer before automatically flushing to the output

Returns:

new mesh buffer instance