Volumetric rendering Example

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 #include "volumetric.h"
 #include <QtDataVisualization/qvalue3daxis.h>
 #include <QtDataVisualization/q3dscene.h>
 #include <QtDataVisualization/q3dcamera.h>
 #include <QtDataVisualization/q3dtheme.h>
 #include <QtDataVisualization/qcustom3dlabel.h>
 #include <QtDataVisualization/q3dscatter.h>
 #include <QtDataVisualization/q3dinputhandler.h>
 #include <QtCore/qmath.h>
 #include <QtWidgets/QLabel>
 #include <QtWidgets/QRadioButton>
 #include <QtWidgets/QSlider>
 #include <QtCore/QDebug>
 #include <QtGui/QOpenGLContext>

 using namespace QtDataVisualization;

 const int lowDetailSize(128);
 const int mediumDetailSize(256);
 const int highDetailSize(512);
 const int colorTableSize(256);
 const int layerDataSize(512);
 const int mineShaftDiameter(1);

 const int airColorIndex(254);
 const int mineShaftColorIndex(255);
 const int layerColorThickness(60);
 const int heightToColorDiv(140);
 const int magmaColorsMin(0);
 const int magmaColorsMax(layerColorThickness);
 const int aboveWaterGroundColorsMin(magmaColorsMax + 1);
 const int aboveWaterGroundColorsMax(aboveWaterGroundColorsMin + layerColorThickness);
 const int underWaterGroundColorsMin(aboveWaterGroundColorsMax + 1);
 const int underWaterGroundColorsMax(underWaterGroundColorsMin + layerColorThickness);
 const int waterColorsMin(underWaterGroundColorsMax + 1);
 const int waterColorsMax(waterColorsMin + layerColorThickness);
 const int terrainTransparency(12);

 static bool isOpenGLES()
 {
 #if defined(QT_OPENGL_ES_2)
     return true;
 #elif (QT_VERSION < QT_VERSION_CHECK(5, 3, 0))
     return false;
 #else
     return QOpenGLContext::currentContext()->isOpenGLES();
 #endif
 }

 VolumetricModifier::VolumetricModifier(Q3DScatter *scatter)
     : m_graph(scatter),
       m_volumeItem(0),
       m_sliceIndexX(lowDetailSize / 2),
       m_sliceIndexY(lowDetailSize / 4),
       m_sliceIndexZ(lowDetailSize / 2),
       m_slicingX(false),
       m_slicingY(false),
       m_slicingZ(false),
       m_mediumDetailRB(0),
       m_highDetailRB(0),
       m_lowDetailData(0),
       m_mediumDetailData(0),
       m_highDetailData(0),
       m_mediumDetailIndex(0),
       m_highDetailIndex(0),
       m_mediumDetailShaftIndex(0),
       m_highDetailShaftIndex(0),
       m_sliceSliderX(0),
       m_sliceSliderY(0),
       m_sliceSliderZ(0),
       m_usingPrimaryTable(true),
       m_sliceLabelX(0),
       m_sliceLabelY(0),
       m_sliceLabelZ(0)
 {
     m_graph->activeTheme()->setType(Q3DTheme::ThemeQt);
     m_graph->setShadowQuality(QAbstract3DGraph::ShadowQualityNone);
     m_graph->scene()->activeCamera()->setCameraPreset(Q3DCamera::CameraPresetFront);
     m_graph->setOrthoProjection(true);
     m_graph->activeTheme()->setBackgroundEnabled(false);

     // Only allow zooming at the center and limit the zoom to 200% to avoid clipping issues
     static_cast<Q3DInputHandler *>(m_graph->activeInputHandler())->setZoomAtTargetEnabled(false);
     m_graph->scene()->activeCamera()->setMaxZoomLevel(200.0f);

     toggleAreaAll(true);

     if (!isOpenGLES()) {
         m_lowDetailData = new QVector<uchar>(lowDetailSize * lowDetailSize * lowDetailSize / 2);
         m_mediumDetailData = new QVector<uchar>(mediumDetailSize * mediumDetailSize * mediumDetailSize / 2);
         m_highDetailData = new QVector<uchar>(highDetailSize * highDetailSize * highDetailSize / 2);

         initHeightMap(QStringLiteral(":/heightmaps/layer_ground.png"), m_groundLayer);
         initHeightMap(QStringLiteral(":/heightmaps/layer_water.png"), m_waterLayer);
         initHeightMap(QStringLiteral(":/heightmaps/layer_magma.png"), m_magmaLayer);

         initMineShaftArray();

         createVolume(lowDetailSize, 0, lowDetailSize, m_lowDetailData);
         excavateMineShaft(lowDetailSize, 0, m_mineShaftArray.size(), m_lowDetailData);

         m_volumeItem = new QCustom3DVolume;
         // Adjust water level to zero with a minor tweak to y-coordinate position and scaling
         m_volumeItem->setScaling(
                     QVector3D(m_graph->axisX()->max() - m_graph->axisX()->min(),
                               (m_graph->axisY()->max() - m_graph->axisY()->min()) * 0.91f,
                               m_graph->axisZ()->max() - m_graph->axisZ()->min()));
         m_volumeItem->setPosition(
                     QVector3D((m_graph->axisX()->max() + m_graph->axisX()->min()) / 2.0f,
                               -0.045f * (m_graph->axisY()->max() - m_graph->axisY()->min()) +
                               (m_graph->axisY()->max() + m_graph->axisY()->min()) / 2.0f,
                               (m_graph->axisZ()->max() + m_graph->axisZ()->min()) / 2.0f));
         m_volumeItem->setScalingAbsolute(false);
         m_volumeItem->setTextureWidth(lowDetailSize);
         m_volumeItem->setTextureHeight(lowDetailSize / 2);
         m_volumeItem->setTextureDepth(lowDetailSize);
         m_volumeItem->setTextureFormat(QImage::Format_Indexed8);
         m_volumeItem->setTextureData(new QVector<uchar>(*m_lowDetailData));

         // Generate color tables.
         m_colorTable1.resize(colorTableSize);
         m_colorTable2.resize(colorTableSize);

         for (int i = 0; i < colorTableSize - 2; i++) {
             if (i < magmaColorsMax) {
                 m_colorTable1[i] = qRgba(130 - (i * 2), 0, 0, 255);
             } else if (i < aboveWaterGroundColorsMax) {
                 m_colorTable1[i] = qRgba((i - magmaColorsMax) * 4,
                                          ((i - magmaColorsMax) * 2) + 120,
                                          (i - magmaColorsMax) * 5, terrainTransparency);
             } else if (i < underWaterGroundColorsMax) {
                 m_colorTable1[i] = qRgba(((layerColorThickness - i - aboveWaterGroundColorsMax)) + 70,
                                          ((layerColorThickness - i - aboveWaterGroundColorsMax) * 2) + 20,
                                          ((layerColorThickness - i - aboveWaterGroundColorsMax)) + 50,
                                          terrainTransparency);
             } else if (i < waterColorsMax) {
                 m_colorTable1[i] = qRgba(0, 0, ((i - underWaterGroundColorsMax) * 2) + 120,
                                          terrainTransparency);
             } else {
                 m_colorTable1[i] = qRgba(0, 0, 0, 0); // Not used
             }
         }
         m_colorTable1[airColorIndex] = qRgba(0, 0, 0, 0);
         m_colorTable1[mineShaftColorIndex] = qRgba(50, 50, 50, 255);

         // The alternate color table just has gray gradients for all terrain except water
         for (int i = 0; i < colorTableSize - 2; i++) {
             if (i < magmaColorsMax) {
                 m_colorTable2[i] = qRgba(((i - aboveWaterGroundColorsMax) * 2),
                                          ((i - aboveWaterGroundColorsMax) * 2),
                                          ((i - aboveWaterGroundColorsMax) * 2), 255);
             } else if (i < underWaterGroundColorsMax) {
                 m_colorTable2[i] = qRgba(((i - aboveWaterGroundColorsMax) * 2),
                                          ((i - aboveWaterGroundColorsMax) * 2),
                                          ((i - aboveWaterGroundColorsMax) * 2), terrainTransparency);
             } else if (i < waterColorsMax) {
                 m_colorTable2[i] = qRgba(0, 0, ((i - underWaterGroundColorsMax) * 2) + 120,
                                          terrainTransparency);
             } else {
                 m_colorTable2[i] = qRgba(0, 0, 0, 0); // Not used
             }
         }
         m_colorTable2[airColorIndex] = qRgba(0, 0, 0, 0);
         m_colorTable2[mineShaftColorIndex] = qRgba(255, 255, 0, 255);

         m_volumeItem->setColorTable(m_colorTable1);

         m_volumeItem->setSliceFrameGaps(QVector3D(0.01f, 0.02f, 0.01f));
         m_volumeItem->setSliceFrameThicknesses(QVector3D(0.0025f, 0.005f, 0.0025f));
         m_volumeItem->setSliceFrameWidths(QVector3D(0.0025f, 0.005f, 0.0025f));
         m_volumeItem->setDrawSliceFrames(false);
         handleSlicingChanges();

         m_graph->addCustomItem(m_volumeItem);

         m_timer.start(0);
     } else {
         // OpenGL ES2 doesn't support 3D textures, so show a warning label instead
         QCustom3DLabel *warningLabel = new QCustom3DLabel(
                     "QCustom3DVolume is not supported with OpenGL ES2",
                     QFont(),
                     QVector3D(0.0f, 0.5f, 0.0f),
                     QVector3D(1.5f, 1.5f, 0.0f),
                     QQuaternion());
         warningLabel->setPositionAbsolute(true);
         warningLabel->setFacingCamera(true);
         m_graph->addCustomItem(warningLabel);
     }

     QObject::connect(m_graph, &QAbstract3DGraph::currentFpsChanged, this,
                      &VolumetricModifier::handleFpsChange);
     QObject::connect(&m_timer, &QTimer::timeout, this,
                      &VolumetricModifier::handleTimeout);

 }

 VolumetricModifier::~VolumetricModifier()
 {
     delete m_graph;
 }

 void VolumetricModifier::setFpsLabel(QLabel *fpsLabel)
 {
     m_fpsLabel = fpsLabel;
 }

 void VolumetricModifier::setMediumDetailRB(QRadioButton *button)
 {
     m_mediumDetailRB = button;
 }

 void VolumetricModifier::setHighDetailRB(QRadioButton *button)
 {
     m_highDetailRB = button;
 }

 void VolumetricModifier::setSliceLabels(QLabel *xLabel, QLabel *yLabel, QLabel *zLabel)
 {
     m_sliceLabelX = xLabel;
     m_sliceLabelY = yLabel;
     m_sliceLabelZ = zLabel;

     adjustSliceX(m_sliceSliderX->value());
     adjustSliceY(m_sliceSliderY->value());
     adjustSliceZ(m_sliceSliderZ->value());
 }

 void VolumetricModifier::setAlphaMultiplierLabel(QLabel *label)
 {
     m_alphaMultiplierLabel = label;
 }

 void VolumetricModifier::sliceX(int enabled)
 {
     m_slicingX = enabled;
     handleSlicingChanges();
 }

 void VolumetricModifier::sliceY(int enabled)
 {
     m_slicingY = enabled;
     handleSlicingChanges();
 }

 void VolumetricModifier::sliceZ(int enabled)
 {
     m_slicingZ = enabled;
     handleSlicingChanges();
 }

 void VolumetricModifier::adjustSliceX(int value)
 {
     if (m_volumeItem) {
         m_sliceIndexX = value / (1024 / m_volumeItem->textureWidth());
         if (m_sliceIndexX == m_volumeItem->textureWidth())
             m_sliceIndexX--;
         if (m_volumeItem->sliceIndexX() != -1)
             m_volumeItem->setSliceIndexX(m_sliceIndexX);
         m_sliceLabelX->setPixmap(
                     QPixmap::fromImage(m_volumeItem->renderSlice(Qt::XAxis, m_sliceIndexX)));
     }
 }

 void VolumetricModifier::adjustSliceY(int value)
 {
     if (m_volumeItem) {
         m_sliceIndexY = value / (1024 / m_volumeItem->textureHeight());
         if (m_sliceIndexY == m_volumeItem->textureHeight())
             m_sliceIndexY--;
         if (m_volumeItem->sliceIndexY() != -1)
             m_volumeItem->setSliceIndexY(m_sliceIndexY);
         m_sliceLabelY->setPixmap(
                     QPixmap::fromImage(m_volumeItem->renderSlice(Qt::YAxis, m_sliceIndexY)));
     }
 }

 void VolumetricModifier::adjustSliceZ(int value)
 {
     if (m_volumeItem) {
         m_sliceIndexZ = value / (1024 / m_volumeItem->textureDepth());
         if (m_sliceIndexZ == m_volumeItem->textureDepth())
             m_sliceIndexZ--;
         if (m_volumeItem->sliceIndexZ() != -1)
             m_volumeItem->setSliceIndexZ(m_sliceIndexZ);
         m_sliceLabelZ->setPixmap(
                     QPixmap::fromImage(m_volumeItem->renderSlice(Qt::ZAxis, m_sliceIndexZ)));
     }
 }

 void VolumetricModifier::handleFpsChange(qreal fps)
 {
     const QString fpsFormat = QStringLiteral("FPS: %1");
     int fps10 = int(fps * 10.0);
     m_fpsLabel->setText(fpsFormat.arg(qreal(fps10) / 10.0));
 }

 void VolumetricModifier::handleTimeout()
 {
     if (!m_mediumDetailRB->isEnabled()) {
         if (m_mediumDetailIndex != mediumDetailSize) {
             m_mediumDetailIndex = createVolume(mediumDetailSize, m_mediumDetailIndex, 4,
                                                m_mediumDetailData);
         } else if (m_mediumDetailShaftIndex != m_mineShaftArray.size()) {
             m_mediumDetailShaftIndex = excavateMineShaft(mediumDetailSize, m_mediumDetailShaftIndex,
                                                          1, m_mediumDetailData );
         } else {
             m_mediumDetailRB->setEnabled(true);
             QString label = QStringLiteral("Medium (%1x%2x%1)");
             m_mediumDetailRB->setText(label.arg(mediumDetailSize).arg(mediumDetailSize / 2));
         }
     } else if (!m_highDetailRB->isEnabled()) {
         if (m_highDetailIndex != highDetailSize) {
             m_highDetailIndex = createVolume(highDetailSize, m_highDetailIndex, 1,
                                              m_highDetailData);
         } else if (m_highDetailShaftIndex != m_mineShaftArray.size()) {
             m_highDetailShaftIndex = excavateMineShaft(highDetailSize, m_highDetailShaftIndex, 1,
                                                        m_highDetailData);
         } else  {
             m_highDetailRB->setEnabled(true);
             QString label = QStringLiteral("High (%1x%2x%1)");
             m_highDetailRB->setText(label.arg(highDetailSize).arg(highDetailSize / 2));
             m_timer.stop();
         }
     }
 }

 void VolumetricModifier::toggleLowDetail(bool enabled)
 {
     if (enabled && m_volumeItem) {
         m_volumeItem->setTextureData(new QVector<uchar>(*m_lowDetailData));
         m_volumeItem->setTextureDimensions(lowDetailSize, lowDetailSize / 2, lowDetailSize);
         adjustSliceX(m_sliceSliderX->value());
         adjustSliceY(m_sliceSliderY->value());
         adjustSliceZ(m_sliceSliderZ->value());
     }
 }

 void VolumetricModifier::toggleMediumDetail(bool enabled)
 {
     if (enabled && m_volumeItem) {
         m_volumeItem->setTextureData(new QVector<uchar>(*m_mediumDetailData));
         m_volumeItem->setTextureDimensions(mediumDetailSize, mediumDetailSize / 2, mediumDetailSize);
         adjustSliceX(m_sliceSliderX->value());
         adjustSliceY(m_sliceSliderY->value());
         adjustSliceZ(m_sliceSliderZ->value());
     }
 }

 void VolumetricModifier::toggleHighDetail(bool enabled)
 {
     if (enabled && m_volumeItem) {
         m_volumeItem->setTextureData(new QVector<uchar>(*m_highDetailData));
         m_volumeItem->setTextureDimensions(highDetailSize, highDetailSize / 2, highDetailSize);
         adjustSliceX(m_sliceSliderX->value());
         adjustSliceY(m_sliceSliderY->value());
         adjustSliceZ(m_sliceSliderZ->value());
     }
 }

 void VolumetricModifier::setFpsMeasurement(bool enabled)
 {
     m_graph->setMeasureFps(enabled);
     if (enabled)
         m_fpsLabel->setText(QStringLiteral("Measuring..."));
     else
         m_fpsLabel->setText(QString());
 }

 void VolumetricModifier::setSliceSliders(QSlider *sliderX, QSlider *sliderY, QSlider *sliderZ)
 {
     m_sliceSliderX = sliderX;
     m_sliceSliderY = sliderY;
     m_sliceSliderZ = sliderZ;

     // Set sliders to interesting values
     m_sliceSliderX->setValue(715);
     m_sliceSliderY->setValue(612);
     m_sliceSliderZ->setValue(715);
 }

 void VolumetricModifier::changeColorTable(int enabled)
 {
     if (m_volumeItem) {
         if (enabled)
             m_volumeItem->setColorTable(m_colorTable2);
         else
             m_volumeItem->setColorTable(m_colorTable1);

         m_usingPrimaryTable = !enabled;

         // Rerender image labels
         adjustSliceX(m_sliceSliderX->value());
         adjustSliceY(m_sliceSliderY->value());
         adjustSliceZ(m_sliceSliderZ->value());
     }
 }

 void VolumetricModifier::setPreserveOpacity(bool enabled)
 {

     if (m_volumeItem) {
         m_volumeItem->setPreserveOpacity(enabled);

         // Rerender image labels
         adjustSliceX(m_sliceSliderX->value());
         adjustSliceY(m_sliceSliderY->value());
         adjustSliceZ(m_sliceSliderZ->value());
     }
 }

 void VolumetricModifier::setTransparentGround(bool enabled)
 {
     if (m_volumeItem) {
         int newAlpha = enabled ? terrainTransparency : 255;
         for (int i = aboveWaterGroundColorsMin; i < underWaterGroundColorsMax; i++) {
             QRgb oldColor1 = m_colorTable1.at(i);
             QRgb oldColor2 = m_colorTable2.at(i);
             m_colorTable1[i] = qRgba(qRed(oldColor1), qGreen(oldColor1), qBlue(oldColor1), newAlpha);
             m_colorTable2[i] = qRgba(qRed(oldColor2), qGreen(oldColor2), qBlue(oldColor2), newAlpha);
         }
         if (m_usingPrimaryTable)
             m_volumeItem->setColorTable(m_colorTable1);
         else
             m_volumeItem->setColorTable(m_colorTable2);
         adjustSliceX(m_sliceSliderX->value());
         adjustSliceY(m_sliceSliderY->value());
         adjustSliceZ(m_sliceSliderZ->value());
     }
 }

 void VolumetricModifier::setUseHighDefShader(bool enabled)
 {
     if (m_volumeItem) {
         m_volumeItem->setUseHighDefShader(enabled);
     }
 }

 void VolumetricModifier::adjustAlphaMultiplier(int value)
 {
     if (m_volumeItem) {
         float mult;
         if (value > 100)
             mult = float(value - 99) / 2.0f;
         else
             mult = float(value) / float(500 - value * 4);
         m_volumeItem->setAlphaMultiplier(mult);
         QString labelFormat = QStringLiteral("Alpha multiplier: %1");
         m_alphaMultiplierLabel->setText(labelFormat.arg(
                                             QString::number(m_volumeItem->alphaMultiplier(), 'f', 3)));

         // Rerender image labels
         adjustSliceX(m_sliceSliderX->value());
         adjustSliceY(m_sliceSliderY->value());
         adjustSliceZ(m_sliceSliderZ->value());
     }
 }

 void VolumetricModifier::toggleAreaAll(bool enabled)
 {
     if (enabled) {
         m_graph->axisX()->setRange(0.0f, 1000.0f);
         m_graph->axisY()->setRange(-600.0f, 600.0f);
         m_graph->axisZ()->setRange(0.0f, 1000.0f);
         m_graph->axisX()->setSegmentCount(5);
         m_graph->axisY()->setSegmentCount(6);
         m_graph->axisZ()->setSegmentCount(5);
     }
 }

 void VolumetricModifier::toggleAreaMine(bool enabled)
 {
     if (enabled) {
         m_graph->axisX()->setRange(350.0f, 850.0f);
         m_graph->axisY()->setRange(-500.0f, 100.0f);
         m_graph->axisZ()->setRange(350.0f, 900.0f);
         m_graph->axisX()->setSegmentCount(10);
         m_graph->axisY()->setSegmentCount(6);
         m_graph->axisZ()->setSegmentCount(11);
     }
 }

 void VolumetricModifier::toggleAreaMountain(bool enabled)
 {
     if (enabled) {
         m_graph->axisX()->setRange(300.0f, 600.0f);
         m_graph->axisY()->setRange(-100.0f, 400.0f);
         m_graph->axisZ()->setRange(300.0f, 600.0f);
         m_graph->axisX()->setSegmentCount(9);
         m_graph->axisY()->setSegmentCount(5);
         m_graph->axisZ()->setSegmentCount(9);
     }
 }

 void VolumetricModifier::setDrawSliceFrames(int enabled)
 {
     if (m_volumeItem)
         m_volumeItem->setDrawSliceFrames(enabled);
 }

 void VolumetricModifier::initHeightMap(QString fileName, QVector<uchar> &layerData)
 {
     QImage heightImage(fileName);

     layerData.resize(layerDataSize * layerDataSize);
     const uchar *bits = heightImage.bits();
     int index = 0;
     QVector<QRgb> colorTable = heightImage.colorTable();
     for (int i = 0; i < layerDataSize; i++) {
         for (int j = 0; j < layerDataSize; j++) {
             layerData[index] = qRed(colorTable.at(bits[index]));
             index++;
         }
     }
 }

 int VolumetricModifier::createVolume(int textureSize, int startIndex, int count,
                                      QVector<uchar> *textureData)
 {
     // Generate volume from layer data.
     int index = startIndex * textureSize * textureSize / 2.0f;
     int endIndex = startIndex + count;
     if (endIndex > textureSize)
         endIndex = textureSize;
     QVector<uchar> magmaHeights(textureSize);
     QVector<uchar> waterHeights(textureSize);
     QVector<uchar> groundHeights(textureSize);
     float multiplier = float(layerDataSize) / float(textureSize);
     for (int i = startIndex; i < endIndex; i++) {
         // Generate layer height arrays
         for (int l = 0; l < textureSize; l++) {
             int layerIndex = (int(i * multiplier) * layerDataSize + int(l * multiplier));
             magmaHeights[l] = int(m_magmaLayer.at(layerIndex));
             waterHeights[l] = int(m_waterLayer.at(layerIndex));
             groundHeights[l] = int(m_groundLayer.at(layerIndex));
         }
         for (int j = 0; j < textureSize / 2; j++) {
             for (int k = 0; k < textureSize; k++) {
                 int colorIndex;
                 int height((layerDataSize - (j * 2 * multiplier)) / 2);
                 if (height < magmaHeights.at(k)) {
                     // Magma layer
                     colorIndex = int((float(height) / heightToColorDiv)
                                      * float(layerColorThickness)) + magmaColorsMin;
                 } else if (height < groundHeights.at(k) && height < waterHeights.at(k)) {
                     // Ground layer below water
                     colorIndex = int((float(waterHeights.at(k) - height) / heightToColorDiv)
                                      * float(layerColorThickness)) + underWaterGroundColorsMin;
                 } else if (height < waterHeights.at(k)) {
                     // Water layer where water goes over ground
                     colorIndex = int((float(height - magmaHeights.at(k)) / heightToColorDiv)
                                      * float(layerColorThickness)) + waterColorsMin;
                 } else if (height <= groundHeights.at(k)) {
                     // Ground above water
                     colorIndex = int((float(height - waterHeights.at(k)) / heightToColorDiv)
                                      * float(layerColorThickness)) + aboveWaterGroundColorsMin;
                 } else {
                     // Rest is air
                     colorIndex = airColorIndex;
                 }

                 (*textureData)[index] = colorIndex;
                 index++;
             }
         }
     }
     return endIndex;
 }

 int VolumetricModifier::excavateMineShaft(int textureSize, int startIndex, int count,
                                           QVector<uchar> *textureData)
 {
     int endIndex = startIndex + count;
     if (endIndex > m_mineShaftArray.size())
         endIndex = m_mineShaftArray.size();
     int shaftSize = mineShaftDiameter * textureSize / lowDetailSize;
     for (int i = startIndex; i < endIndex; i++) {
         QVector3D shaftStart(m_mineShaftArray.at(i).first);
         QVector3D shaftEnd(m_mineShaftArray.at(i).second);
         int shaftLen = (shaftEnd - shaftStart).length() * lowDetailSize;
         int dataX = shaftStart.x() * textureSize - (shaftSize / 2);
         int dataY = (shaftStart.y() * textureSize - (shaftSize / 2)) / 2;
         int dataZ = shaftStart.z() * textureSize - (shaftSize / 2);
         int dataIndex = dataX + (dataY * textureSize) + dataZ * (textureSize * textureSize / 2);
         if (shaftStart.x() != shaftEnd.x()) {
             for (int j = 0; j <= shaftLen; j++) {
                 excavateMineBlock(textureSize, dataIndex, shaftSize, textureData);
                 dataIndex += shaftSize;
             }
         } else if (shaftStart.y() != shaftEnd.y()) {
             shaftLen /= 2; // Vertical shafts are half as long
             for (int j = 0; j <= shaftLen; j++) {
                 excavateMineBlock(textureSize, dataIndex, shaftSize, textureData);
                 dataIndex += textureSize * shaftSize;
             }
         } else {
             for (int j = 0; j <= shaftLen; j++) {
                 excavateMineBlock(textureSize, dataIndex, shaftSize, textureData);
                 dataIndex += (textureSize * textureSize / 2) * shaftSize;
             }
         }

     }
     return endIndex;
 }

 void VolumetricModifier::excavateMineBlock(int textureSize, int dataIndex, int size,
                                            QVector<uchar> *textureData)
 {
     for (int k = 0; k < size; k++) {
         int curIndex = dataIndex + (k * textureSize * textureSize / 2);
         for (int l = 0; l < size; l++) {
             curIndex = dataIndex + (k * textureSize * textureSize / 2)
                     + (l * textureSize);
             for (int m = 0; m < size; m++) {
                 if (textureData->at(curIndex) != airColorIndex)
                     (*textureData)[curIndex] = mineShaftColorIndex;
                 curIndex++;
             }

         }
     }
 }

 void VolumetricModifier::handleSlicingChanges()
 {
     if (m_volumeItem) {
         if (m_slicingX || m_slicingY || m_slicingZ) {
             // Only show slices of selected dimensions
             m_volumeItem->setDrawSlices(true);
             m_volumeItem->setSliceIndexX(m_slicingX ? m_sliceIndexX : -1);
             m_volumeItem->setSliceIndexY(m_slicingY ? m_sliceIndexY : -1);
             m_volumeItem->setSliceIndexZ(m_slicingZ ? m_sliceIndexZ : -1);
         } else {
             // Show slice frames for all dimenstions when not actually slicing
             m_volumeItem->setDrawSlices(false);
             m_volumeItem->setSliceIndexX(m_sliceIndexX);
             m_volumeItem->setSliceIndexY(m_sliceIndexY);
             m_volumeItem->setSliceIndexZ(m_sliceIndexZ);
         }
     }
 }

 void VolumetricModifier::initMineShaftArray()
 {
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.7f, 0.1f, 0.7f),
                                                     QVector3D(0.7f, 0.8f, 0.7f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.7f, 0.7f, 0.5f),
                                                     QVector3D(0.7f, 0.7f, 0.7f));

     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.4f, 0.7f, 0.7f),
                                                     QVector3D(0.7f, 0.7f, 0.7f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.4f, 0.7f, 0.7f),
                                                     QVector3D(0.4f, 0.7f, 0.8f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.45f, 0.7f, 0.7f),
                                                     QVector3D(0.45f, 0.7f, 0.8f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.5f, 0.7f, 0.7f),
                                                     QVector3D(0.5f, 0.7f, 0.8f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.55f, 0.7f, 0.7f),
                                                     QVector3D(0.55f, 0.7f, 0.8f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.7f, 0.7f),
                                                     QVector3D(0.6f, 0.7f, 0.8f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.65f, 0.7f, 0.7f),
                                                     QVector3D(0.65f, 0.7f, 0.8f));

     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.5f, 0.6f, 0.7f),
                                                     QVector3D(0.7f, 0.6f, 0.7f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.5f, 0.6f, 0.7f),
                                                     QVector3D(0.5f, 0.6f, 0.8f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.55f, 0.6f, 0.7f),
                                                     QVector3D(0.55f, 0.6f, 0.8f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.6f, 0.7f),
                                                     QVector3D(0.6f, 0.6f, 0.8f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.65f, 0.6f, 0.7f),
                                                     QVector3D(0.65f, 0.6f, 0.8f));

     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.7f, 0.6f, 0.4f),
                                                     QVector3D(0.7f, 0.6f, 0.7f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.6f, 0.45f),
                                                     QVector3D(0.8f, 0.6f, 0.45f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.6f, 0.5f),
                                                     QVector3D(0.8f, 0.6f, 0.5f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.6f, 0.55f),
                                                     QVector3D(0.8f, 0.6f, 0.55f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.6f, 0.6f),
                                                     QVector3D(0.8f, 0.6f, 0.6f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.6f, 0.65f),
                                                     QVector3D(0.8f, 0.6f, 0.65f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.6f, 0.7f),
                                                     QVector3D(0.8f, 0.6f, 0.7f));

     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.7f, 0.7f, 0.4f),
                                                     QVector3D(0.7f, 0.7f, 0.7f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.7f, 0.45f),
                                                     QVector3D(0.8f, 0.7f, 0.45f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.7f, 0.5f),
                                                     QVector3D(0.8f, 0.7f, 0.5f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.7f, 0.55f),
                                                     QVector3D(0.8f, 0.7f, 0.55f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.7f, 0.6f),
                                                     QVector3D(0.8f, 0.7f, 0.6f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.7f, 0.65f),
                                                     QVector3D(0.8f, 0.7f, 0.65f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.7f, 0.7f),
                                                     QVector3D(0.8f, 0.7f, 0.7f));

     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.7f, 0.8f, 0.5f),
                                                     QVector3D(0.7f, 0.8f, 0.7f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.8f, 0.55f),
                                                     QVector3D(0.8f, 0.8f, 0.55f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.8f, 0.6f),
                                                     QVector3D(0.8f, 0.8f, 0.6f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.8f, 0.65f),
                                                     QVector3D(0.8f, 0.8f, 0.65f));
     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.6f, 0.8f, 0.7f),
                                                     QVector3D(0.8f, 0.8f, 0.7f));

     m_mineShaftArray << QPair<QVector3D, QVector3D>(QVector3D(0.7f, 0.1f, 0.4f),
                                                     QVector3D(0.7f, 0.7f, 0.4f));
 }