Rendering distance in Qt Quick 3D

bluezoo · 22 Sept 2024, 07:46

Hi

I realise that most of the discussion here is about Qt3D, but i have a question about Qt Quick 3D. Even in basic example, the max rendering distance from the camera seems to be fixed.

E.g. positioning a sphere at the origin looks like this

But when you zoom out one step further, the sphere disappears:

I see there is a clipFar property on the PerspectiveCamera that i am using, but it doesn't seem to change this behaviour. Is there any way to get it to keep rendering a larger distance away?

Thanks in advance.

Minimal QML for this is as below:

import QtQuick
import QtQuick3D
import QtQuick3D.Helpers

Item {
    anchors.fill: parent

    Node {
        id: sceneRoot

        Model {
            source: "#Sphere"
            materials: [
                PrincipledMaterial {
                    baseColor: "red"
                }
            ]

            scale: Qt.vector3d(10.0, 20.0, 20.0)
            position:  Qt.vector3d(-100.0, 200.0, 0.0)
            eulerRotation.y: 30
        }
    }

    View3D {
        anchors.fill: parent
        importScene: sceneRoot

        environment: ExtendedSceneEnvironment {
            backgroundMode: SceneEnvironment.SkyBox
            lightProbe: Texture {
                textureData: ProceduralSkyTextureData{}
            }

            InfiniteGrid {
                gridInterval: 100
            }
        }

        Node {
            id: originNode
            eulerRotation.x: -60

            PerspectiveCamera {
                id: cameraNode
                z: 400

                clipFar: 100000.0
            }
        }

        OrbitCameraController {
            origin: originNode
            camera: cameraNode
        }
    }
}

johngod · wrote on 22 Sept 2024, 07:46

@bluezoo Hi

This seems like a bug of OrbitController. I replaced in your code moving the camera with the mouse whell and changing clipFar to different distances, it works.

import QtQuick
import QtQuick3D
import QtQuick3D.Helpers


Window {
    width: 640
    height: 480
    visible: true
    title: qsTr("Hello World")

    View3D {
        anchors.fill: parent
        camera: cameraNode

        environment: ExtendedSceneEnvironment {
            backgroundMode: SceneEnvironment.SkyBox
            lightProbe: Texture {
                textureData: ProceduralSkyTextureData{}
            }

            InfiniteGrid {
                gridInterval: 100
            }
        }

        Node {
            id: originNode
            //eulerRotation.x: -60
            PerspectiveCamera {
                id: cameraNode
                y: 100
                z: 3000
                clipNear: 1
                clipFar: 20000
                onPositionChanged: console.log("camera position: ", position)
            }

            Model {
                source: "#Sphere"
                materials: [
                    PrincipledMaterial {
                        baseColor: "red"
                    }
                ]

                scale: Qt.vector3d(10.0, 20.0, 20.0)
                //position:  Qt.vector3d(-100.0, 200.0, 0.0)
                //eulerRotation.y: 30
            }

        }//originNode

        /*OrbitCameraController {
            anchors.fill: parent
            origin: originNode
            camera: cameraNode
        }*/

    }//View3D

    MouseArea {
        anchors.fill: parent
        onWheel: {
            console.log("angleDelta: ", wheel.angleDelta.y)
            if (wheel.angleDelta.y > 0)
                cameraNode.position.z += 100
            else
                cameraNode.position.z -= 100
        }
    }
}

If you comment MouseArea and uncomment OrbitCameraController it will fail. Note that I adated your code slighty has it was crashing, also remove the euler rotations for simplicity. Please fill a bug report at https://bugreports.qt.io
As a workaround you could try to mimic OrbitCameraController with MouseArea and quaternions which is not very trivial, or try to scale down the all view, so that it will not go further than the 10000 distance units.

bluezoo · 24 Sept 2024, 02:27

Ah I see - thanks for working this out...this was going to be a showstopper for what I was trying to achieve, so this is much appreciated. I will work on a replacement for the OrbitCameraController, and file the bug report. Apologies for the non-working code - I excised it from a larger project and didn't get a chance to test it before I posted.

johngod · wrote on 24 Sept 2024, 02:27

@bluezoo Hi again

Here is quick fix fully working, I just checked OrbitCameraController.qml code, indeed it has the clipNear and clipFar values hardcoded. Add a new qml file to your project, call it NewController or whatever, copy paste the OrbitCameraController.qml code and remove the connection that is causing the bug. Then just use the NewController component instead of OrbitCameraController.

NewController.qml:

// Copyright (C) 2022 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only

import QtQuick
import QtQuick3D

Item {
    id: root
    required property Node origin
    required property Camera camera

    property real xSpeed: 0.1
    property real ySpeed: 0.1

    property bool xInvert: false
    property bool yInvert: true

    property bool mouseEnabled: true
    property bool panEnabled: true

    readonly property bool inputsNeedProcessing: status.useMouse || status.isPanning

    implicitWidth: parent.width
    implicitHeight: parent.height

    /*Connections {
        target: root.camera
        function onZChanged() {
            // Adjust near/far values based on distance
            let distance = root.camera.z
            if (distance < 1) {
                root.camera.clipNear = 0.01
                root.camera.clipFar = 100
                if (camera.z === 0) {
                    console.warn("camera z set to 0, setting it to near clip")
                    root.camera.z = camera.clipNear
                    }
            } else if (distance < 100) {
                root.camera.clipNear = 0.1
                root.camera.clipFar = 1000
            } else {
                root.camera.clipNear = 1
                root.camera.clipFar = 10000
            }
        }
    }*/

    DragHandler {
        id: dragHandler
        target: null
        enabled: root.mouseEnabled
        acceptedModifiers: Qt.NoModifier
        onCentroidChanged: {
            root.mouseMoved(Qt.vector2d(centroid.position.x, centroid.position.y), false);
        }

        onActiveChanged: {
            if (active)
                root.mousePressed(Qt.vector2d(centroid.position.x, centroid.position.y));
            else
                root.mouseReleased(Qt.vector2d(centroid.position.x, centroid.position.y));
        }
    }

    DragHandler {
        id: ctrlDragHandler
        target: null
        enabled: root.mouseEnabled && root.panEnabled
        acceptedModifiers: Qt.ControlModifier
        onCentroidChanged: {
            root.panEvent(Qt.vector2d(centroid.position.x, centroid.position.y));
        }

        onActiveChanged: {
            if (active)
                root.startPan(Qt.vector2d(centroid.position.x, centroid.position.y));
            else
                root.endPan();
        }
    }

    PinchHandler {
        id: pinchHandler
        target: null
        enabled: root.mouseEnabled

        property real distance: 0.0
        onCentroidChanged: {
            root.panEvent(Qt.vector2d(centroid.position.x, centroid.position.y))
        }

        onActiveChanged: {
            if (active) {
                root.startPan(Qt.vector2d(centroid.position.x, centroid.position.y))
                distance = root.camera.z
            } else {
                root.endPan()
                distance = 0.0
            }
        }
        onScaleChanged: {
            root.camera.z = distance * (1 / scale)
        }
    }

    TapHandler {
        onTapped: root.forceActiveFocus() // qmllint disable signal-handler-parameters
    }

    WheelHandler {
        id: wheelHandler
        orientation: Qt.Vertical
        target: null
        enabled: root.mouseEnabled
        acceptedDevices: PointerDevice.Mouse | PointerDevice.TouchPad
        onWheel: event => {
            let delta = -event.angleDelta.y * 0.01;
            root.camera.z += root.camera.z * 0.1 * delta
        }
    }

    function mousePressed(newPos) {
        root.forceActiveFocus()
        status.currentPos = newPos
        status.lastPos = newPos
        status.useMouse = true;
    }

    function mouseReleased(newPos) {
        status.useMouse = false;
    }

    function mouseMoved(newPos: vector2d) {
        status.currentPos = newPos;
    }

    function startPan(pos: vector2d) {
        status.isPanning = true;
        status.currentPanPos = pos;
        status.lastPanPos = pos;
    }

    function endPan() {
        status.isPanning = false;
    }

    function panEvent(newPos: vector2d) {
        status.currentPanPos = newPos;
    }

    FrameAnimation {
        id: updateTimer
        running: root.inputsNeedProcessing
        onTriggered: status.processInput(frameTime * 100)
    }

    QtObject {
        id: status

        property bool useMouse: false
        property bool isPanning: false

        property vector2d lastPos: Qt.vector2d(0, 0)
        property vector2d lastPanPos: Qt.vector2d(0, 0)
        property vector2d currentPos: Qt.vector2d(0, 0)
        property vector2d currentPanPos: Qt.vector2d(0, 0)

        function negate(vector) {
            return Qt.vector3d(-vector.x, -vector.y, -vector.z)
        }

        function processInput(frameDelta) {
            if (useMouse) {
                // Get the delta
                var rotationVector = root.origin.eulerRotation;
                var delta = Qt.vector2d(lastPos.x - currentPos.x,
                                        lastPos.y - currentPos.y);
                // rotate x
                var rotateX = delta.x * xSpeed * frameDelta
                if (xInvert)
                    rotateX = -rotateX;
                rotationVector.y += rotateX;

                // rotate y
                var rotateY = delta.y * -ySpeed * frameDelta
                if (yInvert)
                    rotateY = -rotateY;
                rotationVector.x += rotateY;
                origin.setEulerRotation(rotationVector);
                lastPos = currentPos;
            }
            if (isPanning) {
                let delta = currentPanPos.minus(lastPanPos);
                delta.x = -delta.x

                delta.x = (delta.x / root.width) * camera.z * frameDelta
                delta.y = (delta.y / root.height) * camera.z * frameDelta

                let velocity = Qt.vector3d(0, 0, 0)
                // X Movement
                let xDirection = origin.right
                velocity = velocity.plus(Qt.vector3d(xDirection.x * delta.x,
                                                     xDirection.y * delta.x,
                                                     xDirection.z * delta.x));
                // Y Movement
                let yDirection = origin.up
                velocity = velocity.plus(Qt.vector3d(yDirection.x * delta.y,
                                                     yDirection.y * delta.y,
                                                     yDirection.z * delta.y));

                origin.position = origin.position.plus(velocity)

                lastPanPos = currentPanPos
            }
        }
    }
}

In main.qml replace OrbitCameraController with NewController

NewController {
            anchors.fill: parent
            origin: originNode
            camera: cameraNode
        }

Edit: I created a bug report here https://bugreports.qt.io/browse/QTBUG-129253

Edit 2: I see you also created a bug report, thank you, I did search before I post the bug report but since I did not find it, I went ahead, sorry :)