Encapsulates a Shader Program. More...
| Import Statement: | import Qt3D.Render 2.4 |
| 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.
|
[read-only] log : string |
Holds the log of the current shader program. This is useful to diagnose a compilation failure of the shader program.
|
[read-only] 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.
