Qt3DRender.QParameter

Provides storage for a name and value pair. This maps to a shader uniform. More…

Synopsis

Functions

• def name ()

• def value ()

Slots

• def setName (name)

• def setValue (dv)

Signals

• def nameChanged (name)

• def valueChanged (value)

Detailed Description

A QParameter can be referenced by a QRenderPass , QTechnique , QEffect , QMaterial , QTechniqueFilter , QRenderPassFilter . At runtime, depending on which shader is selected for a given step of the rendering, the value contained in a QParameter will be converted and uploaded if the shader contains a uniform with a name matching that of the QParameter .

QParameter *param = new QParameter();
param->setName(QStringLiteral("diffuseColor"));
param->setValue(QColor::fromRgbF(0.0f, 0.0f, 1.0f, 1.0f));

// Alternatively you can create and set a QParameter this way
QParameter *param2 = new QParameter(QStringLiteral("diffuseColor"), QColor::fromRgbF(0.0f, 0.0f, 1.0f, 1.0f));

// Such QParameters will work with the following GLSL uniform shader declarations
// uniform vec4 diffuseColor;
// uniform vec3 diffuseColor;
// uniform vec2 diffuseColor;
// uniform float diffuseColor;

Note

some care must be taken to ensure the value wrapped by a QParameter can actually be converted to what the real uniform expect. Giving a value stored as an int where the actual shader uniform is of type float could result in undefined behaviors.

Note

when the targeted uniform is an array, the name should be the name of the uniform with [0] appended to it.

QParameter *param = new QParameter();
QVariantList values = QVariantList() << 0.0f << 1.0f << 2.0f << 3.0f << 4.0f << 883.0f << 1340.0f << 1584.0f;

param->setName(QStringLiteral("diffuseValues[0]"));
param->setValue(values);

// Matching GLSL shader uniform  declaration
// uniform float diffuseValues[8];

When it comes to texture support, the QParameter value should be set to the appropriate QAbstractTexture subclass that matches the sampler type of the shader uniform.

QTexture2D *texture = new QTexture2D();
...
QParameter *param = new QParameter();
param->setName(QStringLiteral("diffuseTexture"));
param->setValue(QVariant::fromValue(texture));

// Works with the following GLSL uniform shader declaration
// uniform sampler2D diffuseTexture

See also

QAbstractTexture

class PySide2.Qt3DRender.Qt3DRender.QParameter([parent=None])

PySide2.Qt3DRender.Qt3DRender.QParameter(name, texture[, parent=None])

PySide2.Qt3DRender.Qt3DRender.QParameter(name, value[, parent=None])

param parent

QNode

param name

unicode

param texture

QAbstractTexture

param value

object

Constructs a new QParameter with the specified parent .

PySide2.Qt3DRender.Qt3DRender.QParameter.name()

Return type

unicode

See also

setName()

PySide2.Qt3DRender.Qt3DRender.QParameter.nameChanged(name)

Parameters

name – unicode

PySide2.Qt3DRender.Qt3DRender.QParameter.setName(name)

Parameters

name – unicode

See also

name()

PySide2.Qt3DRender.Qt3DRender.QParameter.setValue(dv)

Parameters

dv – object

See also

value()

PySide2.Qt3DRender.Qt3DRender.QParameter.value()

Return type

object

See also

setValue()

PySide2.Qt3DRender.Qt3DRender.QParameter.valueChanged(value)

Parameters

value – object