Encapsulates a Shader Program. More...
Import Statement: | import Qt3D.Render |
Since: | Qt 5.5 |
Instantiates: | QShaderProgram |
ShaderProgram class 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]; |
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:
Parameter { name: "myColor"; value: "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)); }
computeShaderCode : string
Holds the compute shader code used by this shader program.
computeShaderGraph : string
Holds the URL to the compute shader graph used by this shader program builder.
[since 5.15] format : enumeration
Holds the format of the code provided on the ShaderProgram. The default is ShaderProgram.GLSL
This property was introduced in Qt 5.15.
fragmentShaderCode : string
Holds the fragment shader code used by this shader program.
fragmentShaderGraph : string
Holds the URL to the fragment shader graph used by this shader program builder.
geometryShaderCode : string
Holds the geometry shader code used by this shader program.
geometryShaderGraph : string
Holds the URL to the geometry shader graph used by this shader program builder.
log : string
Holds the log of the current shader program. This is useful to diagnose a compilation failure of the shader program.
status : enumeration
Holds the status of the current shader program.
tessellationControlShaderCode : string
Holds the tesselation control shader code used by this shader program.
tessellationControlShaderGraph : string
Holds the URL to the tesselation control shader graph used by this shader program builder.
tessellationEvaluationShaderCode : string
Holds the tesselation evaluation shader code used by this shader program.
tessellationEvaluationShaderGraph : string
Holds the URL to the tesselation evaluation shader graph used by this shader program builder.
vertexShaderCode : string
Holds the vertex shader code used by this shader program.
vertexShaderGraph : string
Holds the URL to the vertex shader graph used by this shader program builder.
string loadSource(url sourceUrl)
Returns the shader code loaded from sourceUrl.
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Licensed under the GNU Free Documentation License, Version 1.3.
https://doc.qt.io/qt-6.2/qml-qt3d-render-shaderprogram.html