- Qt 5.15
- Qt 3D
- C++ Classes
- QAttribute
- Qt 5.15.11 Reference Documentation

# QAttribute Class

class Qt3DRender::QAttribute

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

Header: | #include <Qt3DRender/QAttribute>
qmake: | QT += 3drender
Instantiated By: | Attribute
Inherits: | Qt3DCore::QNode

- List of all members, including inherited members

## Public Types

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

## Properties

- attributeType : AttributeType
- buffer : Qt3DRender::QBuffer*
- byteOffset : uint
- byteStride : uint
- count : uint

- divisor : uint
- name : QString
- vertexBaseType : VertexBaseType
- vertexSize : uint

## Public Functions

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

## Public Slots

void | setAttributeType(AttributeType attributeType)
void | setBuffer(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(VertexBaseType type)
void | setVertexSize(uint size)

## Signals

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

## Related Non-Members

typedef | 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.

Constant | Value
--- | ---
`Qt3DRender::QAttribute::VertexAttribute` | `0`
`Qt3DRender::QAttribute::IndexAttribute` | `1`
`Qt3DRender::QAttribute::DrawIndirectAttribute` | `2`

### enum QAttribute::VertexBaseType

The type of the data.

Constant | Value
--- | ---
`Qt3DRender::QAttribute::Byte` | `0`
`Qt3DRender::QAttribute::UnsignedByte` | `1`
`Qt3DRender::QAttribute::Short` | `2`
`Qt3DRender::QAttribute::UnsignedShort` | `3`
`Qt3DRender::QAttribute::Int` | `4`
`Qt3DRender::QAttribute::UnsignedInt` | `5`
`Qt3DRender::QAttribute::HalfFloat` | `6`
`Qt3DRender::QAttribute::Float` | `7`
`Qt3DRender::QAttribute::Double` | `8`

## Property Documentation

### attributeType : AttributeType

Holds the attribute type.

Access functions:

AttributeType | attributeType() const
void | setAttributeType(AttributeType attributeType)

Notifier signal:

void | attributeTypeChanged(AttributeType attributeType)

### buffer : Qt3DRender::QBuffer*

Holds the buffer.

Access functions:

QBuffer * | buffer() const
void | setBuffer(QBuffer *buffer)

Notifier signal:

void | bufferChanged(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:

VertexBaseType | vertexBaseType() const
void | setVertexBaseType(VertexBaseType type)

Notifier signal:

void | vertexBaseTypeChanged(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

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

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

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

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

### QAttribute::QAttribute(QNode *parent = nullptr)

Constructs a new QAttribute with parent.

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

The signal is emitted with vertexSize when the dataSize changes.

### `[signal]` void QAttribute::dataTypeChanged(VertexBaseType vertexBaseType)

The signal is emitted with vertexBaseType when the dataType changed.

### `[static]` 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]` 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]` 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]` 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]` 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

### typedef QBufferPtr