Rotations Example

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#include "scatterdatamodifier.h" #include <QtDataVisualization/qscatterdataproxy.h> #include <QtDataVisualization/qvalue3daxis.h> #include <QtDataVisualization/q3dscene.h> #include <QtDataVisualization/q3dcamera.h> #include <QtDataVisualization/qscatter3dseries.h> #include <QtDataVisualization/q3dtheme.h> #include <QtDataVisualization/QCustom3DItem> #include <QtCore/qmath.h> using namespace QtDataVisualization; static const float verticalRange = 8.0f; static const float horizontalRange = verticalRange; static const float ellipse_a = horizontalRange / 3.0f; static const float ellipse_b = verticalRange; static const float doublePi = float(M_PI) * 2.0f; static const float radiansToDegrees = 360.0f / doublePi; static const float animationFrames = 30.0f; ScatterDataModifier::ScatterDataModifier(Q3DScatter *scatter) : m_graph(scatter), m_fieldLines(12), m_arrowsPerLine(16), m_magneticField(new QScatter3DSeries), m_sun(new QCustom3DItem), m_magneticFieldArray(0), m_angleOffset(0.0f), m_angleStep(doublePi / m_arrowsPerLine / animationFrames) { m_graph->setShadowQuality(QAbstract3DGraph::ShadowQualityNone); m_graph->scene()->activeCamera()->setCameraPreset(Q3DCamera::CameraPresetFront); // Magnetic field lines use custom narrow arrow m_magneticField->setItemSize(0.2f); m_magneticField->setMesh(QAbstract3DSeries::MeshUserDefined); m_magneticField->setUserDefinedMesh(QStringLiteral(":/mesh/narrowarrow.obj")); QLinearGradient fieldGradient(0, 0, 16, 1024); fieldGradient.setColorAt(0.0, Qt::black); fieldGradient.setColorAt(1.0, Qt::white); m_magneticField->setBaseGradient(fieldGradient); m_magneticField->setColorStyle(Q3DTheme::ColorStyleRangeGradient); // For 'sun' we use a custom large sphere m_sun->setScaling(QVector3D(0.07f, 0.07f, 0.07f)); m_sun->setMeshFile(QStringLiteral(":/mesh/largesphere.obj")); QImage sunColor = QImage(2, 2, QImage::Format_RGB32); sunColor.fill(QColor(0xff, 0xbb, 0x00)); m_sun->setTextureImage(sunColor); m_graph->addSeries(m_magneticField); m_graph->addCustomItem(m_sun); // Configure the axes according to the data m_graph->axisX()->setRange(-horizontalRange, horizontalRange); m_graph->axisY()->setRange(-verticalRange, verticalRange); m_graph->axisZ()->setRange(-horizontalRange, horizontalRange); m_graph->axisX()->setSegmentCount(int(horizontalRange)); m_graph->axisZ()->setSegmentCount(int(horizontalRange)); QObject::connect(&m_rotationTimer, &QTimer::timeout, this, &ScatterDataModifier::triggerRotation); toggleRotation(); generateData(); } ScatterDataModifier::~ScatterDataModifier() { delete m_graph; } void ScatterDataModifier::generateData() { // Reusing existing array is computationally cheaper than always generating new array, even if // all data items change in the array, if the array size doesn't change. if (!m_magneticFieldArray) m_magneticFieldArray = new QScatterDataArray; int arraySize = m_fieldLines * m_arrowsPerLine; if (arraySize != m_magneticFieldArray->size()) m_magneticFieldArray->resize(arraySize); QScatterDataItem *ptrToDataArray = &m_magneticFieldArray->first(); for (float i = 0; i < m_fieldLines; i++) { float horizontalAngle = (doublePi * i) / m_fieldLines; float xCenter = ellipse_a * qCos(horizontalAngle); float zCenter = ellipse_a * qSin(horizontalAngle); // Rotate - arrow always tangential to origin QQuaternion yRotation = QQuaternion::fromAxisAndAngle(0.0f, 1.0f, 0.0f, horizontalAngle * radiansToDegrees); for (float j = 0; j < m_arrowsPerLine; j++) { // Calculate point on ellipse centered on origin and parallel to x-axis float verticalAngle = ((doublePi * j) / m_arrowsPerLine) + m_angleOffset; float xUnrotated = ellipse_a * qCos(verticalAngle); float y = ellipse_b * qSin(verticalAngle); // Rotate the ellipse around y-axis float xRotated = xUnrotated * qCos(horizontalAngle); float zRotated = xUnrotated * qSin(horizontalAngle); // Add offset float x = xCenter + xRotated; float z = zCenter + zRotated; QQuaternion zRotation = QQuaternion::fromAxisAndAngle(0.0f, 0.0f, 1.0f, verticalAngle * radiansToDegrees); QQuaternion totalRotation = yRotation * zRotation; ptrToDataArray->setPosition(QVector3D(x, y, z)); ptrToDataArray->setRotation(totalRotation); ptrToDataArray++; } } if (m_graph->selectedSeries() == m_magneticField) m_graph->clearSelection(); m_magneticField->dataProxy()->resetArray(m_magneticFieldArray); } void ScatterDataModifier::setFieldLines(int lines) { m_fieldLines = lines; generateData(); } void ScatterDataModifier::setArrowsPerLine(int arrows) { m_angleOffset = 0.0f; m_angleStep = doublePi / m_arrowsPerLine / animationFrames; m_arrowsPerLine = arrows; generateData(); } void ScatterDataModifier::triggerRotation() { m_angleOffset += m_angleStep; generateData(); } void ScatterDataModifier::toggleSun() { m_sun->setVisible(!m_sun->isVisible()); } void ScatterDataModifier::toggleRotation() { if (m_rotationTimer.isActive()) m_rotationTimer.stop(); else m_rotationTimer.start(15); }