QAttribute Class

class Qt3DCore::QAttribute

Defines an attribute and how data should be read from a QBuffer. More...

Header: #include <Qt3DCore/QAttribute>
CMake: find_package(Qt6 REQUIRED COMPONENTS 3dcore)
target_link_libraries(mytarget PRIVATE Qt6::3dcore)
qmake: QT += 3dcore
Instantiated By: Attribute
Inherits: Qt3DCore::QNode

Public Types

enum AttributeType { VertexAttribute, IndexAttribute, DrawIndirectAttribute }
enum VertexBaseType { Byte, UnsignedByte, Short, UnsignedShort, Int, …, Double }

Properties

Public Functions

QAttribute(Qt3DCore::QNode *parent = nullptr)
QAttribute(Qt3DCore::QBuffer *buf, Qt3DCore::QAttribute::VertexBaseType type, uint dataSize, uint count, uint offset = 0, uint stride = 0, Qt3DCore::QNode *parent = nullptr)
QAttribute(Qt3DCore::QBuffer *buf, const QString &name, Qt3DCore::QAttribute::VertexBaseType type, uint dataSize, uint count, uint offset = 0, uint stride = 0, Qt3DCore::QNode *parent = nullptr)
Qt3DCore::QAttribute::AttributeType attributeType() const
Qt3DCore::QBuffer *buffer() const
uint byteOffset() const
uint byteStride() const
uint count() const
uint divisor() const
QString name() const
Qt3DCore::QAttribute::VertexBaseType vertexBaseType() const
uint vertexSize() const

Public Slots

void setAttributeType(Qt3DCore::QAttribute::AttributeType attributeType)
void setBuffer(Qt3DCore::QBuffer *buffer)
void setByteOffset(uint byteOffset)
void setByteStride(uint byteStride)
void setCount(uint count)
void setDivisor(uint divisor)
void setName(const QString &name)
void setVertexBaseType(Qt3DCore::QAttribute::VertexBaseType type)
void setVertexSize(uint size)

Signals

void attributeTypeChanged(Qt3DCore::QAttribute::AttributeType attributeType)
void bufferChanged(Qt3DCore::QBuffer *buffer)
void byteOffsetChanged(uint byteOffset)
void byteStrideChanged(uint byteStride)
void countChanged(uint count)
void dataSizeChanged(uint vertexSize)
void dataTypeChanged(Qt3DCore::QAttribute::VertexBaseType vertexBaseType)
void divisorChanged(uint divisor)
void nameChanged(const QString &name)
void vertexBaseTypeChanged(Qt3DCore::QAttribute::VertexBaseType vertexBaseType)
void vertexSizeChanged(uint vertexSize)

Static Public Members

QString defaultColorAttributeName()
QString defaultJointIndicesAttributeName()
QString defaultJointWeightsAttributeName()
QString defaultNormalAttributeName()
QString defaultPositionAttributeName()
QString defaultTangentAttributeName()
QString defaultTextureCoordinate1AttributeName()
QString defaultTextureCoordinate2AttributeName()
QString defaultTextureCoordinateAttributeName()
QBufferPtr

Detailed Description

There are 3 types of attributes.

  • VertexAttribute: used to define data to be read on a per vertex basis
  • IndexAttribute: used to define vertex indices when indexed draw calls are to be used
  • DrawIndirectAttribute: used to specify the DrawIndirect buffer to be used when indirect draw calls are to be used

Note: when an attribute is of type DrawIndirectAttribute, only count, stride and offset are relevant.

When providing your own attributes, it may make sense to name your attribute using helpers such as QAttribute::defaultPositionAttributeName() as that will ensure your geometry will be compatible with picking and the various materials provided in the Qt3DExtras module.

See also QBuffer.

Member Type Documentation

enum QAttribute::AttributeType

The type of the attribute.

ConstantValue
Qt3DCore::QAttribute::VertexAttribute0
Qt3DCore::QAttribute::IndexAttribute1
Qt3DCore::QAttribute::DrawIndirectAttribute2

enum QAttribute::VertexBaseType

The type of the data.

ConstantValue
Qt3DCore::QAttribute::Byte0
Qt3DCore::QAttribute::UnsignedByte1
Qt3DCore::QAttribute::Short2
Qt3DCore::QAttribute::UnsignedShort3
Qt3DCore::QAttribute::Int4
Qt3DCore::QAttribute::UnsignedInt5
Qt3DCore::QAttribute::HalfFloat6
Qt3DCore::QAttribute::Float7
Qt3DCore::QAttribute::Double8

Property Documentation

attributeType : AttributeType

Holds the attribute type.

Access functions:

Qt3DCore::QAttribute::AttributeType attributeType() const
void setAttributeType(Qt3DCore::QAttribute::AttributeType attributeType)

Notifier signal:

void attributeTypeChanged(Qt3DCore::QAttribute::AttributeType attributeType)

buffer : Qt3DCore::QBuffer*

Holds the buffer.

Access functions:

Qt3DCore::QBuffer *buffer() const
void setBuffer(Qt3DCore::QBuffer *buffer)

Notifier signal:

void bufferChanged(Qt3DCore::QBuffer *buffer)

byteOffset : uint

Holds the byte offset.

Access functions:

uint byteOffset() const
void setByteOffset(uint byteOffset)

Notifier signal:

void byteOffsetChanged(uint byteOffset)

byteStride : uint

Holds the byte stride.

Access functions:

uint byteStride() const
void setByteStride(uint byteStride)

Notifier signal:

void byteStrideChanged(uint byteStride)

count : uint

Holds the count.

Access functions:

uint count() const
void setCount(uint count)

Notifier signal:

void countChanged(uint count)

divisor : uint

Holds the divisor.

Access functions:

uint divisor() const
void setDivisor(uint divisor)

Notifier signal:

void divisorChanged(uint divisor)

name : QString

Holds the name.

Access functions:

QString name() const
void setName(const QString &name)

Notifier signal:

void nameChanged(const QString &name)

vertexBaseType : VertexBaseType

Holds the data type.

Access functions:

Qt3DCore::QAttribute::VertexBaseType vertexBaseType() const
void setVertexBaseType(Qt3DCore::QAttribute::VertexBaseType type)

Notifier signal:

void vertexBaseTypeChanged(Qt3DCore::QAttribute::VertexBaseType vertexBaseType)

vertexSize : uint

Holds the data size, it can only be 1 to 4 units (scalars and vectors), 9 units (3x3 matrices) or 16 units (4x4 matrices).

Access functions:

uint vertexSize() const
void setVertexSize(uint size)

Notifier signal:

void vertexSizeChanged(uint vertexSize)

Member Function Documentation

[explicit] QAttribute::QAttribute(Qt3DCore::QNode *parent = nullptr)

Constructs a new QAttribute with parent.

[explicit] QAttribute::QAttribute(Qt3DCore::QBuffer *buf, Qt3DCore::QAttribute::VertexBaseType type, uint dataSize, uint count, uint offset = 0, uint stride = 0, Qt3DCore::QNode *parent = nullptr)

Constructs a new QAttribute from buf of type, dataSize, count, offset, and stride with parent.

[explicit] QAttribute::QAttribute(Qt3DCore::QBuffer *buf, const QString &name, Qt3DCore::QAttribute::VertexBaseType type, uint dataSize, uint count, uint offset = 0, uint stride = 0, Qt3DCore::QNode *parent = nullptr)

Constructs a new QAttribute named name from buf of type, dataSize, count, offset, and stride with parent.

[signal] void QAttribute::dataSizeChanged(uint vertexSize)

The signal is emitted with vertexSize when the dataSize changes.

[signal] void QAttribute::dataTypeChanged(Qt3DCore::QAttribute::VertexBaseType vertexBaseType)

The signal is emitted with vertexBaseType when the dataType changed.

[static invokable] QString QAttribute::defaultColorAttributeName()

QAttribute::defaultColorAttributeName Returns the name of the default color attribute

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

Note: Getter function for property defaultColorAttributeName.

[static] QString QAttribute::defaultJointIndicesAttributeName()

QAttribute::defaultJointIndicesAttributeName Returns the name of the default joint indices attribute

Note: Getter function for property defaultJointIndicesAttributeName.

[static] QString QAttribute::defaultJointWeightsAttributeName()

QAttribute::defaultJointIndicesAttributeName Returns the name of the default joint weights attribute

Note: Getter function for property defaultJointWeightsAttributeName.

[static invokable] QString QAttribute::defaultNormalAttributeName()

QAttribute::defaultNormalAttributeName Returns the name of the default normal attribute

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

Note: Getter function for property defaultNormalAttributeName.

[static invokable] QString QAttribute::defaultPositionAttributeName()

QAttribute::defaultPositionAttributeName Returns the name of the default position attribute

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

Note: Getter function for property defaultPositionAttributeName.

[static invokable] QString QAttribute::defaultTangentAttributeName()

QAttribute::defaultTangentAttributeName Returns the name of the default tangent attribute

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

Note: Getter function for property defaultTangentAttributeName.

[static] QString QAttribute::defaultTextureCoordinate1AttributeName()

QAttribute::defaultTextureCoordinate1AttributeName Returns the name of the default attribute for the second layer of texture coordinates

Note: Getter function for property defaultTextureCoordinate1AttributeName.

[static] QString QAttribute::defaultTextureCoordinate2AttributeName()

QAttribute::defaultTextureCoordinate2AttributeName Returns the name of the default attribute for the third layer of texture coordinates

Note: Getter function for property defaultTextureCoordinate2AttributeName.

[static invokable] QString QAttribute::defaultTextureCoordinateAttributeName()

QAttribute::defaultTextureCoordinateAttributeName Returns the name of the default texture coordinate attribute

Note: This function can be invoked via the meta-object system and from QML. See Q_INVOKABLE.

Note: Getter function for property defaultTextureCoordinateAttributeName.

Related Non-Members

QBufferPtr

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