Animation, 3D development

[A Former User]

Hi! Sorry, that it already just too complex / incomplete for me to test and help with. Can you boil it down to a simpler question or a minimal runnable example that I - or anyone else who reads this - can use to reproduce the issue?

[Naveen_D]

@Wieland ya sure.. i will reproduce it and post the example code..
Can you please guide in the following issue also
Thank you.
https://forum.qt.io/topic/84633/camera-rotation-around-a-mesh

[Naveen_D]

@Wieland Hi,
I have few doubts regarding rotating an object in 3D,
For ex, i have a car model, which i have sliced in blender, to get door as a separate object and whole car as a separate object, i have exported both as .obj files and i have assembled them in the code.
Now what is happening, when i try to rotate the door which is separate object using number animation, it is rotating with respect to car's origin not w.r.t to door's so, i want to rotate it based on it's own axis or origin. not w.r.t car's origin.
I have tried the following code but didn't get the excepted result.

    // Car front door //
    Mesh {
        id: carDoorMesh
        source: "qrc:/Meshes/CarFrontDoor_modified.obj"
    }

    PhongMaterial{
        id: carDoorMaterial
    }

    Transform {
        id: carDoorTransform
        property real userAngle: 0.0

        matrix: {
            var m= Qt.matrix4x4();
            m.translate(Qt.vector3d(0.501096,1.5006,1.78036))
            m.rotate(userAngle, Qt.vector3d(0,1,0))
            m.translate(Qt.vector3d(-0.501096,-1.5006,-1.75036))
            return m
        }
         NumberAnimation on rotationY {
                    to: -45
                    duration: 1000
                    running: true
                }
}

i got the respective values from blender.
Any guidance is appreciated
Thank you.

[A Former User]

@Naveen_D No offense, but this has nothing to do with Qt really but only with your lack of a basic understanding of how transformation matrices work. Seriously, get a book on linear algebra or you'll never get this to work.

[Naveen_D]

@Wieland Hi,
If i want to give color animation for a particular part of the 3d object, here for eg, car tire or door etc how can i do that? i want to show color animation for car tire, from existing color to red and back to same color and once started, it should be running continuously.
I tried with the following code within transform, but didn't get the result

Transform{
                    id: frontRightDoorWheelTireTransform
                    property real userAngle: 0.0
                    property real userDistance: 0.0
                    matrix: {
                        var m= Qt.matrix4x4();
                        m.translate(0.57005,-0.462196,-2.27110)
                        m.rotate(userAngle,Qt.vector3d(1,0,0))
                        m.translate(-0.57005,0.462196,2.27110)
                        return m;
                    }
                    translation: Qt.vector3d(userDistance,0,0)

                    ColorAnimation {
                        id: frontRightDoorWheelTireAnimation
                        from: "#171512"
                        to: "red"
                        duration: 2000
                        running: true
                    }

                }

Thank you,
Naveen

[Naveen_D]

Any updates on the above query.. ?
Thank you.

[A Former User]

What makes you think that you could apply a color animation to a spatial transformation? That doesn't make any sense.

[Naveen_D]

@Wieland Ok thank you...

1. one more thing, i have a scene 3D function in which i am rendering my car entity, but i am not able to rotate it, when it runs the object is still at one place i am not able to move it. can you please guide me through this
   here is the code

import QtQuick 2.5
import Qt3D.Core 2.0
import Qt3D.Render 2.0
import Qt3D.Input 2.0
import Qt3D.Extras 2.0
import QtQuick.Scene3D 2.0
import QtQuick.Window 2.2
import QtQuick.Controls 1.4
import QtQuick.Layouts 1.1

ApplicationWindow {
    id: appWindow
    visible: true
    width: Screen.width
    height: Screen.height

    Rectangle {
        width: parent.width
        height: parent.height
        color: "Transparent"

        // 3D scene
        Scene3D {
            id: scene3d
            anchors.fill: parent
            aspects: "input"

            Entity {
                id: root

                components: [
                    RenderSettings {
                        activeFrameGraph: ForwardRenderer {
                            clearColor: "#0D8EA2"
                            camera: camera
                        }
                    },
                    InputSettings { }
                ]

                Camera {
                    id: camera
                    property real topPosition: 3.0
                    property real topPos: 0.5
                    projectionType: CameraLens.PerspectiveProjection
                    fieldOfView: 25
                    nearPlane : 0.1
                    farPlane : 1000.0
                    position: Qt.vector3d( 15.0, topPosition, 20.5)
                    upVector: Qt.vector3d(0.0,1.0,0.0)
                    viewCenter: carBodySlicedTransform.translation
                }

                OrbitCameraController {camera: camera}
                // car Base
                Mesh{
                    id: baseMesh
                    source: "qrc:/Meshes/CarBase.obj"
                }
                PhongAlphaMaterial{
                    id: baseMaterial
                    diffuse: "#7bc0ce"
                    alpha: 1.0
                }
                Transform{
                    id: baseTransform
                    translation: Qt.vector3d(0.0,-1.0,0.0)
                }

                // car Body sliced
                Mesh {
                    id: carBodySlicedMesh
                    source: "qrc:/Meshes/CarBodySliced.obj"
                }

                PhongAlphaMaterial {
                    id: carBodySlicedMaterial
                    shininess: 500.0
                    specular: "#62788d"
                    diffuse: "#62788d"
                    alpha: 1.0
                }

                Transform {
                    id: carBodySlicedTransform
                    property real userAngle: 0.0
                    property real userDistance: 0.0
                    property real xAngleValue: 0.0
                    property real yAngleValue: 0.0
                    property real zAngleValue: 0.0
                    matrix: {
                        var m = Qt.matrix4x4();
                        m.rotate(userAngle, Qt.vector3d(xAngleValue, yAngleValue, zAngleValue));
                        m.translate(Qt.vector3d(userDistance, 0, 0));
                        return m;
                    }
                    translation: Qt.vector3d(0.0,0.0,0.0)
                    NumberAnimation on rotationY {
                        id: carAnimation
                        to: 360
                        duration: 5000
                        running: false
                    }
                }

                // main car body entity
                Entity {
                    id: carMainEntity
                    components: [ carBodySlicedMesh, carBodySlicedMaterial, carBodySlicedTransform ]
                    // car base entity
                    Entity{
                        id: carBaseEntity
                        components: [baseMesh, baseMaterial, baseTransform]
                    }
                }
            }
        }
    }

2. Also i want to know how to apply animation to zoom the car based certain condition for eg: if i want to show the engine part of the car then i want to zoom the car towards that particular part in show it using animation.
   Thank you

[Naveen_D]

Hi, can anyone guide me.. regarding above question
Thank you

[Naveen_D]

@Wieland Hi, how can i place the camera within the car, so that i can give the inside view of the car in 3D development environment.
Thank you

[Saeed Magdy]

hi is there any good tutorial for this ? thanks