如何在Qt3D中改变光线

Question

如何更改Qt3D中的灯光设置？

我认为它应该是framegraph的一部分，但是没有任何方法与标准的forwardrenderer中的灯光设置相关联。

Answer 1

其中rootEntity是场景中所有其他实体的父级。

Qt3DCore::QEntity *lightEntity = new Qt3DCore::QEntity(rootEntity);
Qt3DRender::QPointLight *light = new Qt3DRender::QPointLight(lightEntity);
light->setColor("white");
light->setIntensity(1.);
lightEntity->addComponent(light);

Answer 2

据我所知，没有直接的灯光设置。

你做的是创造一个聚光灯并调整它。

从Qt3D示例：

/****************************************************************************
**
** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the Qt3D module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL3$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see http://www.qt.io/terms-conditions. For further
** information use the contact form at http://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPLv3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or later as published by the Free
** Software Foundation and appearing in the file LICENSE.GPL included in
** the packaging of this file. Please review the following information to
** ensure the GNU General Public License version 2.0 requirements will be
** met: http://www.gnu.org/licenses/gpl-2.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

import Qt3D 2.0
import Qt3D.Renderer 2.0

Entity {
    id: root

    property vector3d lightPosition: Qt.vector3d(30.0, 30.0, 0.0)
    property vector3d lightIntensity: Qt.vector3d(1.0, 1.0, 1.0)

    readonly property Camera lightCamera: lightCamera
    readonly property matrix4x4 lightViewProjection: lightCamera.projectionMatrix.times(lightCamera.matrix)

    Camera {
        id: lightCamera
        objectName: "lightCameraLens"
        projectionType: CameraLens.PerspectiveProjection
        fieldOfView: 45
        aspectRatio: 1
        nearPlane : 0.1
        farPlane : 200.0
        position: root.lightPosition
        viewCenter: Qt.vector3d(0.0, 0.0, 0.0)
        upVector: Qt.vector3d(0.0, 1.0, 0.0)
    }
}

Full example to light and shadows

---

除此之外，还有QDirectionalLight和QPointLight。