[ui] Viewer3D: move TrackballController code to Python side

Port JS trackball camera controller code to Python for improved performance and stability.

meshroom/ui/components/__init__.py

@@ -3,8 +3,9 @@ def registerTypes():
     from PySide2.QtQml import qmlRegisterType
     from meshroom.ui.components.edge import EdgeMouseArea
     from meshroom.ui.components.filepath import FilepathHelper
-    from meshroom.ui.components.scene3D import Scene3DHelper
+    from meshroom.ui.components.scene3D import Scene3DHelper, TrackballController
 
     qmlRegisterType(EdgeMouseArea, "GraphEditor", 1, 0, "EdgeMouseArea")
     qmlRegisterType(FilepathHelper, "Meshroom.Helpers", 1, 0, "FilepathHelper")  # TODO: uncreatable
     qmlRegisterType(Scene3DHelper, "Meshroom.Helpers", 1, 0, "Scene3DHelper")  # TODO: uncreatable
+    qmlRegisterType(TrackballController, "Meshroom.Helpers", 1, 0, "TrackballController")

meshroom/ui/components/scene3D.py

@@ -1,8 +1,11 @@
-from PySide2.QtCore import QObject, Slot
+from math import acos, pi, sqrt
+
+from PySide2.QtCore import QObject, Slot, QSize, Signal, QPointF
 from PySide2.Qt3DCore import Qt3DCore
 from PySide2.Qt3DRender import Qt3DRender
-from PySide2.QtGui import QVector3D, QQuaternion
+from PySide2.QtGui import QVector3D, QQuaternion, QVector2D
 
+from meshroom.ui.utils import makeProperty
 
 class Scene3DHelper(QObject):
 
@@ -42,7 +45,54 @@ class Scene3DHelper(QObject):
             count += sum([attr.count() for attr in geo.attributes() if attr.name() == "vertexPosition"])
         return count / 3
 
-    @Slot(QQuaternion, QVector3D, result=QVector3D)
+
-    def rotatedVector(self, quaternion, vector):
+class TrackballController(QObject):
-        """ Returns the rotation of 'vector' with 'quaternion'. """
+    """
-        return quaternion.rotatedVector(vector)
+    Trackball-like camera controller.
+    Based on the C++ version from https://github.com/cjmdaixi/Qt3DTrackball
+    """
+
+    _windowSize = QSize()
+    _camera = None
+    _trackballSize = 1.0
+    _rotationSpeed = 5.0
+
+    def projectToTrackball(self, screenCoords):
+        sx = screenCoords.x()
+        sy = self._windowSize.height() - screenCoords.y()
+        p2d = QVector2D(sx / self._windowSize.width() - 0.5, sy / self._windowSize.height() - 0.5)
+        z = 0.0
+        r2 = pow(self._trackballSize, 2)
+        lengthSquared = p2d.lengthSquared()
+        if lengthSquared <= r2 * 0.5:
+            z = sqrt(r2 - lengthSquared)
+        else:
+            z = r2 * 0.5 / p2d.length()
+        return QVector3D(p2d.x(), p2d.y(), z)
+
+    @staticmethod
+    def clamp(x):
+        return max(-1, min(x, 1))
+
+    def createRotation(self, firstPoint, nextPoint):
+        lastPos3D = self.projectToTrackball(firstPoint).normalized()
+        currentPos3D = self.projectToTrackball(nextPoint).normalized()
+        angle = acos(self.clamp(QVector3D.dotProduct(currentPos3D, lastPos3D)))
+        direction = QVector3D.crossProduct(currentPos3D, lastPos3D)
+        return angle, direction
+
+    @Slot(QPointF, QPointF, float)
+    def rotate(self, lastPosition, currentPosition, dt):
+        angle, direction = self.createRotation(lastPosition, currentPosition)
+        rotatedAxis = self._camera.transform().rotation().rotatedVector(direction)
+        angle *= self._rotationSpeed * dt
+        self._camera.rotateAboutViewCenter(QQuaternion.fromAxisAndAngle(rotatedAxis, angle * pi * 180))
+
+    windowSizeChanged = Signal()
+    windowSize = makeProperty(QSize, '_windowSize', windowSizeChanged)
+    cameraChanged = Signal()
+    camera = makeProperty(Qt3DRender.QCamera, '_camera', cameraChanged)
+    trackballSizeChanged = Signal()
+    trackballSize = makeProperty(float, '_trackballSize', trackballSizeChanged)
+    rotationSpeedChanged = Signal()
+    rotationSpeed = makeProperty(float, '_rotationSpeed', rotationSpeedChanged)

meshroom/ui/qml/Viewer3D/DefaultCameraController.qml

@@ -5,6 +5,8 @@ import Qt3D.Input 2.1
 import Qt3D.Logic 2.0
 import QtQml 2.2
 
+import Meshroom.Helpers 1.0
+
 Entity {
     id: root
 
@@ -15,9 +17,9 @@ Entity {
     property bool moving: pressed || (actionAlt.active && keyboardHandler._pressed)
     property alias focus: keyboardHandler.focus
     readonly property bool pickingActive: actionControl.active && keyboardHandler._pressed
-    property real rotationSpeed: 2.0
+    property alias rotationSpeed: trackball.rotationSpeed
-    property size windowSize
+    property alias windowSize: trackball.windowSize
-    property real trackballSize: 1.0
+    property alias trackballSize: trackball.trackballSize
 
     readonly property alias pressed: mouseHandler._pressed
     signal mousePressed(var mouse)
@@ -29,6 +31,11 @@ Entity {
     KeyboardDevice { id: keyboardSourceDevice }
     MouseDevice { id: mouseSourceDevice }
 
+    TrackballController {
+        id: trackball
+        camera: root.camera
+    }
+
     MouseHandler {
         id: mouseHandler
         property bool _pressed
@@ -148,36 +155,6 @@ Entity {
         ]
     }
 
-    // Based on the C++ version from https://github.com/cjmdaixi/Qt3DTrackball
-    function projectToTrackball(screenCoords)
-    {
-        var sx = screenCoords.x, sy = windowSize.height - screenCoords.y;
-        var p2d = Qt.vector2d(sx / windowSize.width - 0.5, sy / windowSize.height - 0.5);
-        var z = 0.0;
-        var r2 = trackballSize * trackballSize;
-        var lengthSquared = p2d.length() * p2d.length();
-        if(lengthSquared <= r2 * 0.5)
-            z = Math.sqrt(r2 - lengthSquared);
-        else
-            z = r2 * 0.5 / p2d.length();
-        return Qt.vector3d(p2d.x, p2d.y, z);
-    }
-
-    function clamp(x)
-    {
-        return Math.max(-1, Math.min(x, 1));
-    }
-
-    function createRotation(firstPoint, nextPoint)
-    {
-        var lastPos3D = projectToTrackball(firstPoint).normalized();
-        var currentPos3D = projectToTrackball(nextPoint).normalized();
-        var obj = {};
-        obj.angle = Math.acos(clamp(currentPos3D.dotProduct(lastPos3D)));
-        obj.dir = currentPos3D.crossProduct(lastPos3D);
-        return obj;
-    }
-
     components: [
         FrameAction {
             onTriggered: {
@@ -189,12 +166,7 @@ Entity {
                     return;
                 }
                 if(actionLMB.active){ // trackball rotation
-                    var res = createRotation(mouseHandler.lastPosition, mouseHandler.currentPosition);
+                    trackball.rotate(mouseHandler.lastPosition, mouseHandler.currentPosition, dt);
-                    var transform = root.camera.components[1]; // transform is camera first component
-                    var currentRotation = transform.rotation;
-                    var rotatedAxis = Scene3DHelper.rotatedVector(transform.rotation, res.dir);
-                    res.angle *= rotationSpeed * dt;
-                    root.camera.rotateAboutViewCenter(transform.fromAxisAndAngle(rotatedAxis, res.angle * Math.PI * 180));
                     mouseHandler.lastPosition = mouseHandler.currentPosition;
                     return;
                 }