qt3d自定义生成mesh图形

qt中提供的基础的QMesh

• 方形体 - Qt3DExtras::QConeMesh
• 圆锥体 - Qt3DExtras::QCuboidMesh
• 圆柱体 - Qt3DExtras::QCylinderMesh
• 文本 - Qt3DExtras::QExtrudedTextMesh
• 平面 - Qt3DExtras::QPlaneMesh
• 球体 - Qt3DExtras::QSphereMesh
• 圆环 - Qt3DExtras::QTorusMesh
• 外部加载 - Qt3DRender::QMesh 从各种格式的外部文件加载网格数据。
  都继承于QGeometryRenderer类。而QGeometryRenderer继承于Qt3DCore::QComponent。很容易知道mesh网格数据是作为组件增加到渲染中的。

红色上面是qt自带绘制出来的3d模型。下面部分是自定义生成空心圆柱体的3d模型，涉及到重写这些类。

查看qt自带mesh分别怎么用的，和提供了什么

SceneModifier::SceneModifier(Qt3DCore::QEntity *rootEntity)
    : m_rootEntity(rootEntity)
{
    // Torus shape data
    //! [0]
    m_torus = new Qt3DExtras::QTorusMesh();
    m_torus->setRadius(1.0f);
    m_torus->setMinorRadius(0.4f);
    m_torus->setRings(100);
    m_torus->setSlices(20);
    //! [0]

    // TorusMesh Transform
    //! [1]
    Qt3DCore::QTransform *torusTransform = new Qt3DCore::QTransform();
    torusTransform->setScale(1.0f);
    torusTransform->setRotation(QQuaternion::fromAxisAndAngle(QVector3D(0.0f, 1.0f, 0.0f), 25.0f));
    torusTransform->setTranslation(QVector3D(5.0f, 4.0f, 0.0f));
    //! [1]

    //! [2]
    Qt3DExtras::QPhongMaterial *torusMaterial = new Qt3DExtras::QPhongMaterial();
    torusMaterial->setDiffuse(QColor(QRgb(0xbeb32b)));
    //! [2]

    // Torus
    //! [3]
    m_torusEntity = new Qt3DCore::QEntity(m_rootEntity);
    m_torusEntity->addComponent(m_torus);
    m_torusEntity->addComponent(torusMaterial);
    m_torusEntity->addComponent(torusTransform);
    Qt3DRender::QObjectPicker *pickerTorus = new Qt3DRender::QObjectPicker(m_torusEntity);
    m_torusEntity->addComponent(pickerTorus);
    connect(pickerTorus, &Qt3DRender::QObjectPicker::clicked, this, &SceneModifier::handlePickerClicked);
    //! [3]

    // Cone shape data
    Qt3DExtras::QConeMesh *cone = new Qt3DExtras::QConeMesh();
    cone->setTopRadius(0.5);
    cone->setBottomRadius(1);
    cone->setLength(3);
    cone->setRings(50);
    cone->setSlices(20);

    // ConeMesh Transform
    Qt3DCore::QTransform *coneTransform = new Qt3DCore::QTransform();
    coneTransform->setScale(1.5f);
    coneTransform->setRotation(QQuaternion::fromAxisAndAngle(QVector3D(1.0f, 0.0f, 0.0f), 45.0f));
    coneTransform->setTranslation(QVector3D(0.0f, 4.0f, -1.5));

    Qt3DExtras::QPhongMaterial *coneMaterial = new Qt3DExtras::QPhongMaterial();
    coneMaterial->setDiffuse(QColor(QRgb(0x928327)));

    // Cone
    m_coneEntity = new Qt3DCore::QEntity(m_rootEntity);
    m_coneEntity->addComponent(cone);
    m_coneEntity->addComponent(coneMaterial);
    m_coneEntity->addComponent(coneTransform);

    // Cylinder shape data
    Qt3DExtras::QCylinderMesh *cylinder = new Qt3DExtras::QCylinderMesh();
    cylinder->setRadius(1);
    cylinder->setLength(3);
    cylinder->setRings(24);
    cylinder->setSlices(24);

    // CylinderMesh Transform
    Qt3DCore::QTransform *cylinderTransform = new Qt3DCore::QTransform();
    cylinderTransform->setScale(1.5f);
    cylinderTransform->setRotation(QQuaternion::fromAxisAndAngle(QVector3D(1.0f, 0.0f, 0.0f), 45.0f));
    cylinderTransform->setTranslation(QVector3D(-5.0f, 4.0f, -1.5));

    Qt3DExtras::QPhongMaterial *cylinderMaterial = new Qt3DExtras::QPhongMaterial();
    cylinderMaterial->setDiffuse(QColor(QRgb(0x928327)));

    // Cylinder
    m_cylinderEntity = new Qt3DCore::QEntity(m_rootEntity);
    m_cylinderEntity->addComponent(cylinder);
    m_cylinderEntity->addComponent(cylinderMaterial);
    m_cylinderEntity->addComponent(cylinderTransform);

    // Cuboid shape data
    Qt3DExtras::QCuboidMesh *cuboid = new Qt3DExtras::QCuboidMesh();

    // CuboidMesh Transform
    Qt3DCore::QTransform *cuboidTransform = new Qt3DCore::QTransform();
    cuboidTransform->setScale(2.0f);
    cuboidTransform->setTranslation(QVector3D(5.0f, -4.0f, 0.0f));

    Qt3DExtras::QPhongMaterial *cuboidMaterial = new Qt3DExtras::QPhongMaterial();
    cuboidMaterial->setDiffuse(QColor(QRgb(0x665423)));

    //Cuboid
    m_cuboidEntity = new Qt3DCore::QEntity(m_rootEntity);
    m_cuboidEntity->addComponent(cuboid);
    m_cuboidEntity->addComponent(cuboidMaterial);
    m_cuboidEntity->addComponent(cuboidTransform);
    Qt3DRender::QObjectPicker *pickerCuboid = new Qt3DRender::QObjectPicker(m_cuboidEntity);
    m_cuboidEntity->addComponent(pickerCuboid);
    connect(pickerCuboid, &Qt3DRender::QObjectPicker::clicked, this, &SceneModifier::handlePickerClicked);

    // Plane shape data
    Qt3DExtras::QPlaneMesh *planeMesh = new Qt3DExtras::QPlaneMesh();
    planeMesh->setWidth(2);
    planeMesh->setHeight(2);

    // Plane mesh transform
    Qt3DCore::QTransform *planeTransform = new Qt3DCore::QTransform();
    planeTransform->setScale(1.3f);
    planeTransform->setRotation(QQuaternion::fromAxisAndAngle(QVector3D(1.0f, 0.0f, 0.0f), 45.0f));
    planeTransform->setTranslation(QVector3D(0.0f, -4.0f, 0.0f));

    Qt3DExtras::QPhongMaterial *planeMaterial = new Qt3DExtras::QPhongMaterial();
    planeMaterial->setDiffuse(QColor(QRgb(0xa69929)));

    // Plane
    m_planeEntity = new Qt3DCore::QEntity(m_rootEntity);
    m_planeEntity->addComponent(planeMesh);
    m_planeEntity->addComponent(planeMaterial);
    m_planeEntity->addComponent(planeTransform);

    // Sphere shape data
    Qt3DExtras::QSphereMesh *sphereMesh = new Qt3DExtras::QSphereMesh();
    sphereMesh->setRings(20);
    sphereMesh->setSlices(20);
    sphereMesh->setRadius(2);

    // Sphere mesh transform
    Qt3DCore::QTransform *sphereTransform = new Qt3DCore::QTransform();

    sphereTransform->setScale(1.3f);
    sphereTransform->setTranslation(QVector3D(-5.0f, -4.0f, 0.0f));

    Qt3DExtras::QPhongMaterial *sphereMaterial = new Qt3DExtras::QPhongMaterial();
    sphereMaterial->setDiffuse(QColor(QRgb(0xa69929)));

    // Sphere
    m_sphereEntity = new Qt3DCore::QEntity(m_rootEntity);
    m_sphereEntity->addComponent(sphereMesh);
    m_sphereEntity->addComponent(sphereMaterial);
    m_sphereEntity->addComponent(sphereTransform);

    //textMesh
    Qt3DExtras::QExtrudedTextMesh* textMesh = new Qt3DExtras::QExtrudedTextMesh();
    textMesh->setDepth(.1f);
    textMesh->setText("Qt3d自带的shapes");

    Qt3DCore::QTransform *textTransform = new Qt3DCore::QTransform();
    textTransform->setScale(1.5f);
    textTransform->setRotation(QQuaternion::fromAxisAndAngle(QVector3D(1.0f, 0.0f, 0.0f), 45.0f));
    textTransform->setTranslation(QVector3D(-6.0f, 8.0f, 0.0f));

    Qt3DExtras::QPhongMaterial *textMaterial = new Qt3DExtras::QPhongMaterial();
    textMaterial->setDiffuse(QColor(QRgb(0x928327)));

    //
    Qt3DCore::QEntity* textEntity = new Qt3DCore::QEntity(m_rootEntity);
    textEntity->addComponent(textMesh);
    textEntity->addComponent(textMaterial);
    textEntity->addComponent(textTransform);

//==============================================================================
    //DHollowCylinderMesh 自定义空心圆柱mesh
    Qt3DExtras::DHollowCylinderMesh* dcylinder = new Qt3DExtras::DHollowCylinderMesh();
    dcylinder->setSlices(100);
    dcylinder->setRings(100);
    dcylinder->setLength(3);
    dcylinder->setOuterRadius(5);
    dcylinder->setInnerRadius(2.5f);

    Qt3DCore::QTransform *dcylinderTransform = new Qt3DCore::QTransform();
    dcylinderTransform->setScale(1.5f);
    dcylinderTransform->setRotation(QQuaternion::fromAxisAndAngle(QVector3D(1.0f, 0.0f, 0.0f), 45.0f));
    dcylinderTransform->setTranslation(QVector3D(0.0f, -15.0f, 0.0f));

    Qt3DExtras::QPhongMaterial *dcylinderMaterial = new Qt3DExtras::QPhongMaterial();
    dcylinderMaterial->setDiffuse(QColor(QRgb(0x928327)));

    Qt3DCore::QEntity* dcylinderEntity = new Qt3DCore::QEntity(m_rootEntity);
    dcylinderEntity->addComponent(dcylinder);
    dcylinderEntity->addComponent(dcylinderMaterial);
    dcylinderEntity->addComponent(dcylinderTransform);
}

自定义图形 （空心圆柱体）

DHollowCylinderMesh.h

#ifndef DHOLLOWCYLINDERMESH_H
#define DHOLLOWCYLINDERMESH_H


#include <Qt3DExtras/qt3dextras_global.h>
#include <Qt3DRender/qgeometryrenderer.h>

QT_BEGIN_NAMESPACE
namespace Qt3DExtras {
class Q_3DEXTRASSHARED_EXPORT DHollowCylinderMesh : public Qt3DRender::QGeometryRenderer
{
    Q_OBJECT
    Q_PROPERTY(int rings READ rings WRITE setRings NOTIFY ringsChanged)
    Q_PROPERTY(int slices READ slices WRITE setSlices NOTIFY slicesChanged)
    Q_PROPERTY(float outerRadius READ outerRadius WRITE setOuterRadius NOTIFY outerRadiusChanged);
    Q_PROPERTY(float innerRadius READ innerRadius WRITE setInnerRadius NOTIFY innerRadiusChanged);
    Q_PROPERTY(float length READ length WRITE setLength NOTIFY lengthChanged)
public:
    explicit DHollowCylinderMesh(Qt3DCore::QNode *parent = nullptr);
    ~DHollowCylinderMesh();
    int rings() const;
    int slices() const;
    float length() const;
    float outerRadius() const;
    float innerRadius() const;
public Q_SLOTS:
    void setRings(int rings);
    void setSlices(int slices);
    void setLength(float length);
    void setOuterRadius(float radius);
    void setInnerRadius(float radius);
Q_SIGNALS:
    void ringsChanged(int rings);
    void slicesChanged(int slices);
    void lengthChanged(float length);
    void outerRadiusChanged(float radius);
    void innerRadiusChanged(float radius);
private:
    // As this is a default provided geometry renderer, no one should be able
    // to modify the QGeometryRenderer's properties
    void setInstanceCount(int instanceCount);
    void setVertexCount(int vertexCount);
    void setIndexOffset(int indexOffset);
    void setFirstInstance(int firstInstance);
    void setRestartIndexValue(int index);
    void setPrimitiveRestartEnabled(bool enabled);
    void setGeometry(Qt3DRender::QGeometry *geometry);
    void setPrimitiveType(PrimitiveType primitiveType);
};
} // namespace Qt3DRender
QT_END_NAMESPACE

#endif // DHOLLOWCYLINDERMESH_H

DHollowCylinderMesh.cpp

#include "dhollowcylindermesh.h"
#include "dhollowcylindergeometry.h"


#ifndef _USE_MATH_DEFINES
# define _USE_MATH_DEFINES // For MSVC
#endif

#include <Qt3DRender/qbuffer.h>
#include <Qt3DRender/qbufferdatagenerator.h>
#include <Qt3DRender/qattribute.h>
#include <QtGui/QVector3D>
#include <qmath.h>


QT_BEGIN_NAMESPACE
using namespace Qt3DRender;
namespace Qt3DExtras {
/*!
 * \class Qt3DExtras::DHollowCylinderMesh
   \ingroup qt3d-extras-geometries
 * \inheaderfile Qt3DExtras/DHollowCylinderMesh
 * \inmodule Qt3DExtras
 *
 * \inherits Qt3DRender::QGeometryRenderer
 *
 * \brief A hollowCylinderMesh mesh.
 */
/*!
 * Constructs a new DHollowCylinderMesh with \a parent.
 */
DHollowCylinderMesh::DHollowCylinderMesh(QNode *parent)
    : QGeometryRenderer(parent)
{
    DHollowCylinderGeometry *geometry = new DHollowCylinderGeometry(this);
    QObject::connect(geometry, &DHollowCylinderGeometry::outerRadiusChanged, this, &DHollowCylinderMesh::outerRadiusChanged);
    QObject::connect(geometry, &DHollowCylinderGeometry::innerRadiusChanged, this, &DHollowCylinderMesh::innerRadiusChanged);
    QObject::connect(geometry, &DHollowCylinderGeometry::ringsChanged, this, &DHollowCylinderMesh::ringsChanged);
    QObject::connect(geometry, &DHollowCylinderGeometry::slicesChanged, this, &DHollowCylinderMesh::slicesChanged);
    QObject::connect(geometry, &DHollowCylinderGeometry::lengthChanged, this, &DHollowCylinderMesh::lengthChanged);
    QGeometryRenderer::setGeometry(geometry);
}

DHollowCylinderMesh::~DHollowCylinderMesh()
{
}
void DHollowCylinderMesh::setRings(int rings)
{
    static_cast<DHollowCylinderGeometry *>(geometry())->setRings(rings);
}
void DHollowCylinderMesh::setSlices(int slices)
{
    static_cast<DHollowCylinderGeometry *>(geometry())->setSlices(slices);
}

void DHollowCylinderMesh::setLength(float length)
{
    static_cast<DHollowCylinderGeometry *>(geometry())->setLength(length);
}
void DHollowCylinderMesh::setOuterRadius(float radius)
{
    static_cast<DHollowCylinderGeometry *>(geometry())->setOuterRadius(radius);
}
void DHollowCylinderMesh::setInnerRadius(float radius)
{
    static_cast<DHollowCylinderGeometry *>(geometry())->setInnerRadius(radius);
}

int DHollowCylinderMesh::rings() const
{
    return static_cast<DHollowCylinderGeometry *>(geometry())->rings();
}

int DHollowCylinderMesh::slices() const
{
    return static_cast<DHollowCylinderGeometry *>(geometry())->slices();
}

float DHollowCylinderMesh::length() const
{
    return static_cast<DHollowCylinderGeometry *>(geometry())->length();
}

float DHollowCylinderMesh::outerRadius() const
{
    return static_cast<DHollowCylinderGeometry *>(geometry())->outerRadius();
}

float DHollowCylinderMesh::innerRadius() const
{
    return static_cast<DHollowCylinderGeometry *>(geometry())->outerRadius();
}


} // namespace Qt3DExtras
QT_END_NAMESPACE

DHollowCylinderGeometry.h

#ifndef DHOLLOWCYLINDERGEOMETRY_H
#define DHOLLOWCYLINDERGEOMETRY_H

#include <Qt3DExtras/qt3dextras_global.h>
#include <Qt3DRender/qgeometry.h>

QT_BEGIN_NAMESPACE
namespace Qt3DRender {
class QAttribute;
class QBuffer;
} // namespace Qt3DRender
namespace Qt3DExtras {

class Q_3DEXTRASSHARED_EXPORT DHollowCylinderGeometry : public Qt3DRender::QGeometry
{
    Q_OBJECT
    Q_PROPERTY(int rings READ rings WRITE setRings NOTIFY ringsChanged)
    Q_PROPERTY(int slices READ slices WRITE setSlices NOTIFY slicesChanged)
    Q_PROPERTY(float innerRadius READ innerRadius WRITE setInnerRadius NOTIFY innerRadiusChanged)
    Q_PROPERTY(float outerRadius READ outerRadius WRITE setOuterRadius NOTIFY outerRadiusChanged)
    Q_PROPERTY(float length READ length WRITE setLength NOTIFY lengthChanged)
    Q_PROPERTY(Qt3DRender::QAttribute *positionAttribute READ positionAttribute CONSTANT)
    Q_PROPERTY(Qt3DRender::QAttribute *normalAttribute READ normalAttribute CONSTANT)
    Q_PROPERTY(Qt3DRender::QAttribute *texCoordAttribute READ texCoordAttribute CONSTANT)
    Q_PROPERTY(Qt3DRender::QAttribute *indexAttribute READ indexAttribute CONSTANT)
public:
    explicit DHollowCylinderGeometry(QNode *parent = nullptr);
    ~DHollowCylinderGeometry();
    void updateVertices();
    void updateIndices();
    int rings() const;
    int slices() const;
    float innerRadius() const;
    float outerRadius() const;
    float length() const;
    Qt3DRender::QAttribute *positionAttribute() const;
    Qt3DRender::QAttribute *normalAttribute() const;
    Qt3DRender::QAttribute *texCoordAttribute() const;
    Qt3DRender::QAttribute *indexAttribute() const;
public Q_SLOTS:
    void setRings(int rings);
    void setSlices(int slices);
    void setLength(float length);
    void setOuterRadius(float radius);
    void setInnerRadius(float radius);

Q_SIGNALS:
    void radiusChanged(float radius);
    void ringsChanged(int rings);
    void slicesChanged(int slices);
    void lengthChanged(float length);
    void outerRadiusChanged(float radius);
    void innerRadiusChanged(float radius);

private:
    //Q_DECLARE_PRIVATE(QCylinderGeometry)
    void init();

    int m_rings;
    int m_slices;
    float m_length;
    float m_outerRadius;
    float m_innerRadius;

    Qt3DRender::QAttribute *m_positionAttribute;
    Qt3DRender::QAttribute *m_normalAttribute;
    Qt3DRender::QAttribute *m_texCoordAttribute;
    Qt3DRender::QAttribute *m_indexAttribute;
    Qt3DRender::QBuffer *m_vertexBuffer;
    Qt3DRender::QBuffer *m_indexBuffer;
};
} // Qt3DExtras
QT_END_NAMESPACE

#endif // DHOLLOWCYLINDERGEOMETRY_H