Parameter QML Type

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

import 语句: import Qt3D.Render 2.12
实例化: QParameter

特性

详细描述

A Parameter can be referenced by a RenderPass , Technique, Effect, Material, TechniqueFilter , RenderPassFilter . At runtime, depending on which shader is selected for a given step of the rendering, the value contained in a Parameter will be converted and uploaded if the shader contains a uniform with a name matching that of the Parameter.

Parameter {
    name: "diffuseColor"
    value: "blue"
}
// Works with the following GLSL uniform shader declarations
// uniform vec4 diffuseColor;
// uniform vec3 diffuseColor;
// uniform vec2 diffuseColor;
// uniform float diffuseColor;
					

注意: some care must be taken to ensure the value wrapped by a Parameter 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.

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

Parameter {
    name: "diffuseValues[0]"
    value: [0.0, 1.0. 2.0, 3.0, 4.0, 883.0, 1340.0, 1584.0]
}
// Matching GLSL shader uniform  declaration
// uniform float diffuseValues[8];
					

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

Parameter {
    name: "diffuseTexture"
    value: Texture2D { ... }
}
// Works with the following GLSL uniform shader declaration
// uniform sampler2D diffuseTexture
					

另请参阅 Qt3DRender::QAbstractTexture .

特性文档编制

name : QString

Specifies the name of the parameter

value : QVariant

Specifies the value of the parameter