QShaderProgram — PyQt Documentation v6.9.0 (original) (raw)

PyQt6.Qt3DRender.QShaderProgram

Inherits from QNode.

Description

Encapsulates a Shader Program.

A shader program consists of several different shaders, such as vertex and fragment shaders.

Qt3D will automatically populate a set of default uniforms if they are encountered during the shader instrospection phase.

Default Uniform Associated Qt3D Parameter name GLSL declaration
ModelMatrix modelMatrix uniform mat4 modelMatrix;
ViewMatrix viewMatrix uniform mat4 viewMatrix;
ProjectionMatrix projectionMatrix uniform mat4 projectionMatrix;
ModelViewMatrix modelView uniform mat4 modelView;
ViewProjectionMatrix viewProjectionMatrix uniform mat4 viewProjectionMatrix;
ModelViewProjectionMatrix modelViewProjection mvp uniform mat4 modelViewProjection; uniform mat4 mvp;
InverseModelMatrix inverseModelMatrix uniform mat4 inverseModelMatrix;
InverseViewMatrix inverseViewMatrix uniform mat4 inverseViewMatrix;
InverseProjectionMatrix inverseProjectionMatrix uniform mat4 inverseProjectionMatrix;
InverseModelViewMatrix inverseModelView uniform mat4 inverseModelView;
InverseViewProjectionMatrix inverseViewProjectionMatrix uniform mat4 inverseViewProjectionMatrix;
InverseModelViewProjectionMatrix inverseModelViewProjection uniform mat4 inverseModelViewProjection;
ModelNormalMatrix modelNormalMatrix uniform mat3 modelNormalMatrix;
ModelViewNormalMatrix modelViewNormal uniform mat3 modelViewNormal;
ViewportMatrix viewportMatrix uniform mat4 viewportMatrix;
InverseViewportMatrix inverseViewportMatrix uniform mat4 inverseViewportMatrix;
AspectRatio (surface width / surface height) aspectRatio uniform float aspectRatio;
Exposure exposure uniform float exposure;
Gamma gamma uniform float gamma;
Time (in nano seconds) time uniform float time;
EyePosition eyePosition uniform vec3 eyePosition;
SkinningPalette skinningPalette[0] const int maxJoints = 100; uniform mat4 skinningPalette[maxJoints];

RHI Support

When writing GLSL 450 shader code to use with Qt 3D’s RHI backend, the default uniforms will be provided as 2 uniform buffer objects.

The binding locations for these is set to bindings 0 for RenderView uniforms and 1 for Command uniforms.

#version 450 core

layout(location = 0) in vec3 vertexPosition;

layout(std140, binding = 0) uniform qt3d_render_view_uniforms { mat4 viewMatrix; mat4 projectionMatrix; mat4 uncorrectedProjectionMatrix; mat4 clipCorrectionMatrix; mat4 viewProjectionMatrix; mat4 inverseViewMatrix; mat4 inverseProjectionMatrix; mat4 inverseViewProjectionMatrix; mat4 viewportMatrix; mat4 inverseViewportMatrix; vec4 textureTransformMatrix; vec3 eyePosition; float aspectRatio; float gamma; float exposure; float time; float yUpInNDC; float yUpInFBO; };

layout(std140, binding = 1) uniform qt3d_command_uniforms { mat4 modelMatrix; mat4 inverseModelMatrix; mat4 modelViewMatrix; mat3 modelNormalMatrix; mat4 inverseModelViewMatrix; mat4 modelViewProjection; mat4 inverseModelViewProjectionMatrix; };

void main() { gl_Position = (projectionMatrix * viewMatrix * modelMatrix * vertexPosition); }

For user defined uniform buffer object, use binding starting at 2 or auto to let Qt 3D work out the binding automatically. Make sure to remain consistent between the different shader stages.

#version 450 core

layout(std140, binding = auto) uniform my_uniforms { vec4 myColor; };

layout(location=0) out vec4 fragColor;

void main() { fragColor = myColor; }

There is no change involved when it comes to feeding values to uniforms.

For the above example, setting myColor could be done with:

QParameter *parameter = new QParameter(); parameter->setName("myColor"); parameter->setValue(QVariant::fromValue(QColor(Qt::blue)));

Textures still have to be defined as standalone uniforms.

#version 450 core

layout(binding=0) uniform sampler2D source;

layout(location=0) out vec4 fragColor;

void main() { fragColor = texture(source, vec2(0.5, 0.5)); }

Enums

Format

This enum identifies the format of the shader code used.

Member Value Description
GLSL 0 OpenGL
SPIRV 1 Vulkan, OpenGL 5

ShaderType

This enum identifies the type of shader used.

Member Value Description
Compute 5 Compute shader
Fragment 1 Fragment shader
Geometry 4 Geometry shader
TessellationControl 2 Tesselation control shader
TessellationEvaluation 3 Tesselation evaluation shader
Vertex 0 Vertex shader

Status

This enum identifies the status of shader used.

Member Value Description
Error 2 An error occurred while compiling the shader
NotReady 0 The shader hasn’t been compiled and linked yet
Ready 1 The shader was successfully compiled

Methods

__init__(parent: QNode = None)

TODO

computeShaderCode() → QByteArray

format() → Format

fragmentShaderCode() → QByteArray

geometryShaderCode() → QByteArray

@staticmethod
loadSource(QUrl) → QByteArray

Returns the shader code loaded from sourceUrl.

log() → str

TODO

setComputeShaderCode(Union[QByteArray, bytes, bytearray, memoryview])

See also

computeShaderCode().

setFormat(Format)

setFragmentShaderCode(Union[QByteArray, bytes, bytearray, memoryview])

See also

fragmentShaderCode().

setGeometryShaderCode(Union[QByteArray, bytes, bytearray, memoryview])

See also

geometryShaderCode().

setShaderCode(ShaderType, Union[QByteArray, bytes, bytearray, memoryview])

Sets the shader code for type of shader to the shaderCode.

setTessellationControlShaderCode(Union[QByteArray, bytes, bytearray, memoryview])

setTessellationEvaluationShaderCode(Union[QByteArray, bytes, bytearray, memoryview])

setVertexShaderCode(Union[QByteArray, bytes, bytearray, memoryview])

See also

vertexShaderCode().

shaderCode(ShaderType) → QByteArray

Returns the shader code for type.

See also

setShaderCode().

status() → Status

Returns the status of the current shader program.

tessellationControlShaderCode() → QByteArray

tessellationEvaluationShaderCode() → QByteArray

vertexShaderCode() → QByteArray

Signals

computeShaderCodeChanged(Union[QByteArray, bytes, bytearray, memoryview])

TODO

formatChanged(Format)

TODO

fragmentShaderCodeChanged(Union[QByteArray, bytes, bytearray, memoryview])

TODO

geometryShaderCodeChanged(Union[QByteArray, bytes, bytearray, memoryview])

TODO

logChanged(Optional[str])

TODO

statusChanged(Status)

TODO

tessellationControlShaderCodeChanged(Union[QByteArray, bytes, bytearray, memoryview])

TODO

tessellationEvaluationShaderCodeChanged(Union[QByteArray, bytes, bytearray, memoryview])

TODO

vertexShaderCodeChanged(Union[QByteArray, bytes, bytearray, memoryview])

TODO