Qt Quick 3D - 灯光示例

演示不同灯光类型的使用。

该示例演示了在应用程序中使用三种不同的灯光类型。

设置场景灯光

定向光

定向光从无限远处的一个无法识别的光源向一个方向发射光线。这与现实生活中阳光的作用方式类似。定向光的范围是无限的，并且不会减弱。

我们将定向光设置为发射红色，并将其围绕 x 轴旋转制作成动画。

DirectionalLight {
    id: light1
    color: Qt.rgba(1.0, 0.1, 0.1, 1.0)
    ambientColor: Qt.rgba(0.1, 0.1, 0.1, 1.0)
    position: Qt.vector3d(0, 200, 0)
    rotation: Quaternion.fromEulerAngles(-135, -90, 0)
    shadowMapQuality: Light.ShadowMapQualityVeryHigh
    pcfFactor: 1
    visible: directionalLightCheckBox.checked
    castsShadow: checkBoxShadows.checked
    brightness: directionalLightSlider.value
    SequentialAnimation on rotation {
        loops: Animation.Infinite
        QuaternionAnimation {
            to: Quaternion.fromEulerAngles(-45, -90, 0)
            duration: 2000
            easing.type: Easing.InOutQuad
        }
        QuaternionAnimation {
            to: Quaternion.fromEulerAngles(-135, -90, 0)
            duration: 2000
            easing.type: Easing.InOutQuad
        }
    }
}

点光源

点光源可以描述为一个球体，从光源中心向各个方向发出强度相同的光。这与灯泡的发光方式类似。

我们将点光源设置为发射绿色，并以 x 坐标为其位置设置动画。

PointLight {
    id: light2
    color: Qt.rgba(0.1, 1.0, 0.1, 1.0)
    ambientColor: Qt.rgba(0.1, 0.1, 0.1, 1.0)
    position: Qt.vector3d(0, 300, 0)
    shadowMapFar: 2000
    shadowMapQuality: Light.ShadowMapQualityHigh
    visible: pointLightCheckBox.checked
    castsShadow: checkBoxShadows.checked
    brightness: pointLightSlider.value
    SequentialAnimation on x {
        loops: Animation.Infinite
        NumberAnimation {
            to: 400
            duration: 2000
            easing.type: Easing.InOutQuad
        }
        NumberAnimation {
            to: 0
            duration: 2000
            easing.type: Easing.InOutQuad
        }
    }
}

点光源

点光源与点光源类似，不同之处在于它以锥形朝一个方向发光，而不是朝所有方向发光。除了圆锥角度外，聚光灯与点光源具有相同的特性和属性。

我们将聚光灯设置为发射暖色，并将其旋转 Y 坐标设置为动画。

SpotLight {
    id: light4
    color: Qt.rgba(1.0, 0.9, 0.7, 1.0)
    ambientColor: Qt.rgba(0.0, 0.0, 0.0, 0.0)
    position: Qt.vector3d(0, 250, 0)
    eulerRotation.x: -45
    shadowMapFar: 2000
    shadowMapQuality: Light.ShadowMapQualityHigh
    visible: spotLightCheckBox.checked
    castsShadow: checkBoxShadows.checked
    brightness: spotLightSlider.value
    coneAngle: 110
    innerConeAngle: 70
    PropertyAnimation on eulerRotation.y {
        loops: Animation.Infinite
        from: 0
        to: -360
        duration: 10000
    }
}

设置场景模型

首先，我们添加两个矩形模型作为场景的地板和后墙。这些模型有助于观察光影。

Model {
    source: "#Rectangle"
    y: -200
    scale: Qt.vector3d(15, 15, 15)
    eulerRotation.x: -90
    materials: [
        PrincipledMaterial {
            baseColor: Qt.rgba(0.8, 0.6, 0.4, 1.0)
        }
    ]
}
Model {
    source: "#Rectangle"
    z: -400
    scale: Qt.vector3d(15, 15, 15)
    materials: [
         PrincipledMaterial {
            baseColor: Qt.rgba(0.8, 0.8, 0.9, 1.0)
        }
    ]
}

然后，我们添加围绕 Y 轴旋转的主徽标模型。

Model {
    id: logoDefault
    source: "qtlogo.mesh"
    scale: Qt.vector3d(5000, 5000, 5000)

    property variant material
    materials: [ material ]

    property bool animate: true
    NumberAnimation on eulerRotation.y {
        running: logoDefault.animate
        loops: Animation.Infinite
        duration: 5000
        from: 0
        to: -360
    }
}

我们还添加了小立方体模型来演示每种灯光的位置和旋转。当用户访问相关滑块时，这些立方体的比例会变大。

Model {
    // Directional Light Marker
    property real size: directionalLightSlider.highlight ? 0.2 : 0.1
    source: "#Cube"
    position: light1.position
    rotation: light1.rotation
    scale: Qt.vector3d(size, size, size * 2)
    materials: [
        PrincipledMaterial {
            baseColor: light1.color
            lighting: PrincipledMaterial.NoLighting
        }
    ]
    castsShadows: false
    visible: directionalLightCheckBox.checked
}
Model {
    // Point Light Marker
    source: "#Sphere"
    position: light2.position
    rotation: light2.rotation
    property real size: pointLightSlider.highlight ? 0.2 : 0.1
    scale: Qt.vector3d(size, size, size)
    materials: [
        PrincipledMaterial {
            baseColor: light2.color
            lighting: PrincipledMaterial.NoLighting
        }
    ]
    castsShadows: false
    visible: pointLightCheckBox.checked
}
Node {
    // Spot Light Marker
    position: light4.position
    rotation: light4.rotation
    property real size: spotLightSlider.highlight ? 0.2 : 0.1
    scale: Qt.vector3d(size, size, size)
    Model {
        source: "#Cone"
        castsShadows: false
        eulerRotation.x: 90
        materials: PrincipledMaterial {
            baseColor: light4.color
            lighting: PrincipledMaterial.NoLighting
        }
    }
    visible: spotLightCheckBox.checked
}

用户可以通过设置面板启用阴影，并分别控制每种灯光的可见度和亮度。

示例项目 @ code.qt.io

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