自定义 QQuick3DGeometry 不显示

问题描述

尝试为 QtQuick3D 实现自定义几何：

mycustomgeometry.h：

#ifndef MYCUSTOMGEOMETRY_H
#define MYCUSTOMGEOMETRY_H

#include <QQuick3DGeometry>

class MyCustomGeometry : public QQuick3DGeometry
{
    Q_OBJECT
public:
    MyCustomGeometry();
    virtual ~MyCustomGeometry();

signals:

public slots:
    void setData(QByteArray vertexData,QByteArray indexData);

};

#endif // MYCUSTOMGEOMETRY_H

mycustomgeometry.cpp：

#include "mycustomgeometry.h"

#include <QVector3D>

// simulate data coming from my application (should look like a cut cuboid)
static unsigned char vertexData[] = {
    0x00,0x00,0xe0,0xb3,0x8c,0xca,0x4c,0xbd,0x1c,0x63,0x89,0x3d,0x60,0x35,0x0c,0xcf,0xa4,0x61,0x64,0x2e,0x37,0xb8,0xcc,0x2a,0xb7,0xbc,0x68,0x2d,0xe4,0x2f,0x80,0xcb,0x18,0xf0,0xcd,0x28,0x2c,0xd8,0xf8,0xce,0xa0,0x20,0xbd
};
static unsigned char indexData[] = {
    0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x00
};

MyCustomGeometry::MyCustomGeometry()
{
    QByteArray v(reinterpret_cast<char*>(::vertexData),sizeof(::vertexData));
    QByteArray i(reinterpret_cast<char*>(::indexData),sizeof(::indexData));
    setData(v,i);
}

MyCustomGeometry::~MyCustomGeometry()
{
}

void MyCustomGeometry::setData(QByteArray vertexData,QByteArray indexData)
{
    clear();
    setPrimitiveType(PrimitiveType::Triangles);
    addAttribute(Attribute::PositionSemantic,Attribute::F32Type);
    addAttribute(Attribute::IndexSemantic,Attribute::U32Type);
    addAttribute(Attribute::normalSemantic,Attribute::F32Type);
    setVertexData(vertexData);
    setIndexData(indexData);
    setStride(sizeof(float) * 3);

    QVector3D boundsMin,boundsMax;
    auto vertices = reinterpret_cast<const float*>(vertexData.constData());
    for(size_t i = 0; i < vertexData.length() / sizeof(float); i += 3)
    {
        for(size_t j = 0; j < 3; j++)
        {
            boundsMin[j] = (std::min(vertices[i + j],i == 0 ? vertices[i + j] : boundsMin[j]));
            boundsMax[j] = (std::max(vertices[i + j],i == 0 ? vertices[i + j] : boundsMax[j]));
        }
    }
    setBounds(boundsMin,boundsMax);
}

main.qml：

import QtQuick 2.15
import QtQuick.Window 2.15
import QtQuick3D 1.15
import QtQuick3D.Helpers 1.15
import QtQuick.Controls 2.15
import MyCustomGeometry 1.0

Window {
    id: mainWindow
    width: 400
    height: 300
    visible: true
    flags: Qt.Tool
    title: qsTr("3D demo")

    View3D {
        id: view
        anchors.fill: parent
        camera: camera
        renderMode: View3D.Overlay

        PerspectiveCamera {
            id: camera
            position: Qt.vector3d(0,200,300)
            eulerRotation.x: -30
        }

        WasdController {
            controlledobject: camera
            mouseEnabled: true
        }

        DirectionalLight {
            eulerRotation.x: -30
        }

        Model {
            id: cube
            objectName: "cube"
            visible: true
            position: Qt.vector3d(-100,0)
            scale: Qt.vector3d(slider.k,slider.k,slider.k)
            source: "#Cube"
            materials: [DefaultMaterial {diffuseColor: "red"}]
            eulerRotation.y: 90
        }

        Model {
            id: sphere
            objectName: "sphere"
            visible: true
            position: Qt.vector3d(100,slider.k)
            //source: "#Sphere"
            geometry: MyCustomGeometry {}
            materials: [DefaultMaterial {diffuseColor: "blue"}]
            eulerRotation.y: 90
        }
    }

    Slider {
        id: slider
        property real k: Math.pow(10,slider.value)
        from: -3; to: 6; value: 3
    }
}

立方体和球体（注释 geometry: 和取消注释 source: 时）正确显示。

但是带有自定义几何图形的模型没有。

我也尝试使用 16 位整数作为索引，但得到了相同的结果。

编辑：在 Qt 6.0.0 上测试过并且可以工作，所以这是一个仅限于 Qt 5.15.2 的问题

解决方法

如果按照 {{3}} 设置 const BotsGrid = () => { const [icons,setIcons] = useState({ SapIcon: SapIcon,ExcelIcon: ExcelIcon,OutlookIcon: OutlookIcon,BrowserIcon: BrowserIcon,OneDriveIcon: OneDriveIcon,XhisIcon: XhisIcon }); 属性，它也适用于 Qt 5：

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