adding Qt3DCore::QEntity to q3dwindow dynamic(push a button to call slots in q3dwindow) cause transform odd.

fisher103

we create 3d object like this in qt5.8-windows:

//build a sphere
m_sphereMesh = new Qt3DExtras::QSphereMesh(m_pRootEntity);
m_mainSphereTransfrom = new Qt3DCore::QTransform(m_pRootEntity);
m_mainSphereMaterial = new Qt3DExtras::QPhongMaterial(m_pRootEntity);

//add component to sphere
Qt3DCore::QEntity *mainEntity = new Qt3DCore::QEntity(m_pRootEntity);
mainEntity->addComponent(m_sphereMesh);
mainEntity->addComponent(m_mainSphereMaterial);
mainEntity->addComponent(m_mainSphereTransfrom);

everything goes well when we do all these(build all spheres) in initial time. but when we add a button to add another sphere during running time, this new build sphere act unnormal for move command like (m_newSphereTransfrom->setTranslation(m_posNewPos);)

but the sphere display normal like pick, set color, or scale. only cannot move or rotate as initial-time build spheres.

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follow are all the source code, when your press the closer button, you will find that new sphere would not moved, but the position return by transform is changed.
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test3d.pro

QT += core gui 3dcore 3drender 3dextras

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

TARGET = test3d
TEMPLATE = app

SOURCES += main.cpp
window3d.cpp
widget3d.cpp

HEADERS += window3d.h
widget3d.h

main.cpp

#include <QApplication>
#include "widget3d.h"

int main(int argc, char *argv[])
{

QApplication a(argc, argv);

Widget3D mainWidget;
mainWidget.show();

return a.exec();

}

window3d.h

#ifndef WINDOW3D_H
#define WINDOW3D_H

#include <Qt3DExtras/Qt3DWindow>
#include <Qt3DCore>
#include <Qt3DExtras/qphongmaterial.h>
#include <QPickEvent>
#include <QmouseEvent>
#include <Qt3DExtras/qcylindermesh.h>
#include <Qt3DExtras/qspheremesh.h>

class Window3D : public Qt3DExtras::Qt3DWindow
{
Q_OBJECT

public:

Window3D(QObject *parent = 0);
~Window3D();

void install3dEnvironment();

void createSphere();

public slots:

void createNewSphere();
void beCloser();

protected:

void addDirectLight(const QVector3D & pos, const QVector3D & dir, float intensity);

private:

Qt3DCore::QEntity *m_pRootEntity;
Qt3DCore::QEntity * m_sphere;
Qt3DExtras::QSphereMesh *m_mesh;
Qt3DExtras::QPhongMaterial *m_material;
Qt3DCore::QTransform *m_transfrom;

Qt3DCore::QEntity * m_newSphere;
Qt3DExtras::QSphereMesh *m_newMesh;
Qt3DExtras::QPhongMaterial *m_newMaterial;
Qt3DCore::QTransform *m_newTransfrom;

};

#endif // WINDOW3D_H

window3d.cpp

#include "window3d.h"
#include <Qt3DRender/QDirectionalLight>
#include <Qt3DRender/QCamera>
#include <Qt3DRender/QCameraLens>
#include <QOrbitCameraController>

Window3D::Window3D(QObject *parent):
m_pRootEntity(0),
m_sphere(0),
m_mesh(0),
m_material(0),
m_transfrom(0),
m_newSphere(0),
m_newMesh(0),
m_newMaterial(0),
m_newTransfrom(0)
{

m_pRootEntity = new Qt3DCore::QEntity();
setRootEntity(m_pRootEntity);
install3dEnvironment();
createSphere();

}

Window3D::~Window3D()
{

}

void Window3D::addDirectLight(const QVector3D & pos, const QVector3D & dir, float intensity)
{

Qt3DCore::QEntity *lightEntity = new Qt3DCore::QEntity(m_pRootEntity);
Qt3DRender::QDirectionalLight *light = new Qt3DRender::QDirectionalLight(m_pRootEntity);
light->setColor("white");
light->setIntensity(intensity);
light->setWorldDirection(dir);
Qt3DCore::QTransform *lightTransform = new Qt3DCore::QTransform(m_pRootEntity);
lightTransform->setTranslation(pos);
lightEntity->addComponent(light);
lightEntity->addComponent(lightTransform);

}

void Window3D::install3dEnvironment()
{

Qt3DRender::QCamera *cameraEntity = camera();
cameraEntity->lens()->setPerspectiveProjection(45.0f, 16.0f/9.0f, 0.1f, 100.0f);
cameraEntity->setPosition(QVector3D(0, 0, 20));
cameraEntity->setUpVector(QVector3D(0, 1, 0));
cameraEntity->setViewCenter(QVector3D(0, 0, 0));

addDirectLight(QVector3D(0, 0, 20), QVector3D(0, 0, -20), 1);

Qt3DExtras::QOrbitCameraController *camController = new Qt3DExtras::QOrbitCameraController(m_pRootEntity);
camController->setCamera(cameraEntity);

}

void Window3D::createSphere()
{

m_mesh = new Qt3DExtras::QSphereMesh(m_pRootEntity);
m_mesh->setRings(20);
m_mesh->setSlices(50);
m_mesh->setRadius(1);

m_transfrom = new Qt3DCore::QTransform(m_pRootEntity);
m_transfrom->setTranslation(QVector3D(-4,0,0));//set position

m_material = new Qt3DExtras::QPhongMaterial(m_pRootEntity);
m_material->setDiffuse("yellow");

m_sphere = new Qt3DCore::QEntity(m_pRootEntity);
m_sphere->addComponent(m_mesh);
m_sphere->addComponent(m_transfrom);
m_sphere->addComponent(m_material);

}

void Window3D::createNewSphere()
{

if (m_newSphere) return;
m_newMesh = new Qt3DExtras::QSphereMesh(m_pRootEntity);
m_newMesh->setRings(20);
m_newMesh->setSlices(50);
m_newMesh->setRadius(2);

m_newTransfrom = new Qt3DCore::QTransform(m_pRootEntity);
m_newTransfrom->setTranslation(QVector3D(4,0,0));//set position

m_newMaterial = new Qt3DExtras::QPhongMaterial(m_pRootEntity);
m_newMaterial->setDiffuse("green");

m_newSphere = new Qt3DCore::QEntity(m_pRootEntity);
m_newSphere->addComponent(m_newMesh);
m_newSphere->addComponent(m_newTransfrom);
m_newSphere->addComponent(m_newMaterial);

}

void Window3D::beCloser()
{

if (m_newSphere && m_sphere)
{
    m_transfrom->setTranslation(m_transfrom->translation()+QVector3D(0.1,0,0));
    m_newTransfrom->setTranslation(m_newTransfrom->translation() + QVector3D(-0.2, 0, 0));

    qDebug() << "new position:" << m_transfrom->translation() << m_newTransfrom->translation();
}

}

widget3d.h

#ifndef WIDGET3D_H
#define WIDGET3D_H

#include "window3d.h"
#include <QWidget>

class Widget3D : public QWidget
{
Q_OBJECT

public:

Widget3D(QObject *parent = 0);
~Widget3D();

private:

Window3D * m_wind3d;

};

#endif // WIDGET3D_H

widget3d.cpp

#include "widget3d.h"
#include <QPushButton>
#include <QHBoxLayout>

Widget3D::Widget3D(QObject *parent)
{

m_wind3d = new Window3D();
QWidget *view3d = QWidget::createWindowContainer(m_wind3d,this);
QSize screenSize = m_wind3d->screen()->size();
view3d->setMinimumSize(QSize(800, 500));
view3d->setMaximumSize(screenSize);

QHBoxLayout *hLayout = new QHBoxLayout(this);
QVBoxLayout *vLayout = new QVBoxLayout(this);

hLayout->addWidget(view3d);
hLayout->addLayout(vLayout);


QPushButton *addNewSphere = new QPushButton(this);
addNewSphere->setText(tr("New Sphere"));
connect(addNewSphere, SIGNAL(clicked()), m_wind3d, SLOT(createNewSphere()));
vLayout->addWidget(addNewSphere);

QPushButton *closerSphere = new QPushButton(this);
closerSphere->setText(tr("Be Closer"));
connect(closerSphere, SIGNAL(clicked()), m_wind3d, SLOT(beCloser()));
vLayout->addWidget(closerSphere);

this->setLayout(hLayout);

}

Widget3D::~Widget3D()
{

}

m.sue

Hi,

you may need to update() the Qt3DWindow explicitly.

-Michael.

fisher103

@m.sue I have tried Qt3DWindow::requestUpdate() after building sphere but it makes no diffrence. Also I call it in the timer, it keeps the same.
Any other advices?

m.sue

Hi,

please show how you create the second sphere, the "set translation" functions and how you call it.

-Michael.

fisher103

@m.sue the creation are the same. like this:
Qt3DCore::QTransform *localTransform = new Qt3DCore::QTransform(m_pRootEntity);
localTransform->setTranslation(pt3d);
m_vecSphereTransform.append(localTransform);

Qt3DExtras::QPhongMaterial *localMaterial = new Qt3DExtras::QPhongMaterial(m_pRootEntity);
localMaterial->setDiffuse(m_colorSphere);
m_vecSphereMaterial.append(localMaterial);

Qt3DCore::QEntity *localEntity = new Qt3DCore::QEntity(m_pRootEntity);

localEntity->addComponent(m_sphereMesh);
localEntity->addComponent(localMaterial);
localEntity->addComponent(localTransform);
m_vecSpheres.push_back(localEntity);

we save the pointer to QTransform into a vector and operate the position with the pointer in a timer.

m.sue

Hi,

I see two difference to how I do it:

I do not set the root entity as parent to the mesh, material nor transform.
I create a new mesh for each sphere.

Hope that helps.

-Michael.

fisher103

@m.sue I remove the root entity as parent to the mesh, material nor transform. it really works, thanks very much....
but I do not know why it acts like that way.