ShaderProgram QML Type

Encapsulates a Shader Program. 更多...

import 语句: import Qt3D.Render 2.5
实例化: QShaderProgram

特性

方法

详细描述

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;
时间
(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:

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));
}
					

特性文档编制

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.


format : enumeration

Holds the format of the code provided on the ShaderProgram 。默认为 ShaderProgram .GLSL


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.


方法文档编制

string loadSource ( url sourceUrl )

Returns the shader code loaded from sourceUrl .