How to add a light to a 3d scene in Qml? - qt

Question

I am developing an application with a cube with 6 different textures in QML.
I made the cube pattern with Blender and attached the texture to the model I created and saved.
But I have a small problem, the textures load correctly but I have shadows that appear and darken the different sides of the cube.
Does anyone have an idea how to remove these shadows?
I put below the code of my application and a screenshot of what I get as a result.
main.qml
import QtQuick 2.12
import QtQuick.Scene3D 2.12
import QtQuick.Window 2.12
Window {
visible: true
width: 640
height: 480
Scene3D
{
id : scene3d
anchors.fill: parent
focus: false
aspects: ["render", "logic", "input"]
hoverEnabled: true
cameraAspectRatioMode: Scene3D.AutomaticAspectRatio
RootEntity
{
id:root
}
}
}
SOrbitCamera.qml
import Qt3D.Core 2.0
import Qt3D.Render 2.0
import Qt3D.Input 2.0
Entity{
id: root
property Camera camera;
property real dt: 0.001
property real linearSpeed: 1
property real lookSpeed: 500
MouseDevice {
id: mouseDevice
sensitivity: 0.007
}
MouseHandler {
id: mh
property vector3d upVect: Qt.vector3d(0, 1, 0)
property point lastPos;
property real pan;
property real tilt;
sourceDevice: mouseDevice
onPanChanged: {
if (camera.position.y < 0.5 && camera.position.y > -3.) {
root.camera.panAboutViewCenter(-pan, upVect);
}
if (camera.position.y > 0.5 && camera.position.y < 3.) {
root.camera.panAboutViewCenter(pan, upVect);
}
if (camera.position.y < 6. && camera.position.y > 3.) {
root.camera.panAboutViewCenter(-pan, upVect);
}
if (camera.position.y > -6. && camera.position.y < -3.) {
root.camera.panAboutViewCenter(pan, upVect);
}
}
onTiltChanged: root.camera.tiltAboutViewCenter(tilt);
onPressed: {
lastPos = Qt.point(mouse.x, mouse.y);
}
onPositionChanged: {
if (mouse.buttons === 1){ // Left button for rotation
pan = -(mouse.x - lastPos.x) * dt * lookSpeed;
tilt = (mouse.y - lastPos.y) * dt * lookSpeed;
console.log(camera.position)
}
lastPos = Qt.point(mouse.x, mouse.y)
}
}
}
RootEntity.qml
import QtQuick 2.0
import QtQuick3D 1.15
import Qt3D.Core 2.12
import Qt3D.Render 2.12
import Qt3D.Extras 2.12
import Qt3D.Input 2.12
Entity {
id: root
//create camera
Camera {
id: mainCamera
projectionType: CameraLens.PerspectiveProjection
fieldOfView: 45
aspectRatio: 16/9
nearPlane : 0.1
farPlane : 1000.0
position: Qt.vector3d(0.0, 4.49373, -3.78577)
upVector: Qt.vector3d( 0.0, 1.0, 0.0 )
viewCenter: cubeTransform.translation
}
//use my class instead of OrbitCameraController
SOrbitCameraController {
id: mainCameraController
camera: mainCamera
}
components: [
RenderSettings {
Viewport {
normalizedRect: Qt.rect(0.0, 0.0, 1.0, 1.0)
RenderSurfaceSelector {
CameraSelector {
id: cameraSelector
camera: mainCamera
FrustumCulling {
ClearBuffers {
buffers: ClearBuffers.AllBuffers
clearColor: "black"
NoDraw {}
}
LayerFilter {
filterMode: LayerFilter.DiscardAnyMatchingLayers
layers: [topLayer]
}
LayerFilter {
filterMode: LayerFilter.AcceptAnyMatchingLayers
layers: [topLayer]
ClearBuffers {
buffers: ClearBuffers.DepthBuffer
}
}
}
}
}
}
},
InputSettings {}
,
ScreenRayCaster
{
id:screenRayCaster
onHitsChanged:
{
drawLineMesh(hits)
}
}
]
Layer {
id: topLayer
recursive: true
}
Entity {
id: cubeEntity
Texture2D {
id:texture
TextureImage {
source: "qrc:/../Downloads/texture.png"
}
}
Mesh {
id: cubeMesh
source: "qrc:/../Downloads/cube.obj"
}
Transform {
id: cubeTransform
translation: Qt.vector3d(0, 0, 0)
}
NormalDiffuseMapMaterial{
id: material
normal: texture
diffuse: texture
specular: texture
}
components: [cubeMesh, cubeTransform, material]
}
}

Answer 1

I add the following code in RootEntity.qml
import QtQuick 2.0
import QtQuick3D 1.15
import Qt3D.Core 2.12
import Qt3D.Render 2.12
import Qt3D.Extras 2.12
import Qt3D.Input 2.12
import QtQuick 2.15
import QtQuick.Window 2.12
Entity {
id: root
Entity {
id: lightEntity
components: [
DirectionalLight{
intensity: 0.5
enabled: true
},
Transform{
translation: Qt.vector3d(0,50,0)
}
]
}
//create camera
Camera {
id: mainCamera
projectionType: CameraLens.PerspectiveProjection
fieldOfView: 45
aspectRatio: 16/9
nearPlane : 0.1
farPlane : 1000.0
position: Qt.vector3d(0.0, 4.49373, -3.78577)
upVector: Qt.vector3d( 0.0, 1.0, 0.0 )
viewCenter: cubeTransform.translation
}
SOrbitCameraController {
id: mainCameraController
camera: mainCamera
}
components: [
RenderSettings {
Viewport {
normalizedRect: Qt.rect(0.0, 0.0, 1.0, 1.0)
RenderSurfaceSelector {
CameraSelector {
id: cameraSelector
camera: mainCamera
FrustumCulling {
ClearBuffers {
buffers: ClearBuffers.AllBuffers
clearColor: "black"
NoDraw {}
}
LayerFilter {
filterMode: LayerFilter.DiscardAnyMatchingLayers
layers: [topLayer]
}
LayerFilter {
filterMode: LayerFilter.AcceptAnyMatchingLayers
layers: [topLayer]
ClearBuffers {
buffers: ClearBuffers.DepthBuffer
}
}
}
}
}
}
},
InputSettings {}
]
Layer {
id: topLayer
recursive: true
}
/*
CuboidMesh{
id: cubeMesh
xExtent: 1
yExtent: 1
zExtent: 1
}*/
Entity {
id: cubeEntity
Texture2D {
id:texture
TextureImage {
source: "qrc:/../Downloads/texture.png"
}
}
Mesh {
id: cubeMesh
source: "qrc:/../Downloads/cube.obj"
}
Transform {
id: cubeTransform
translation: Qt.vector3d(0, 0, 0)
}
NormalDiffuseMapMaterial{
id: material
normal: texture
diffuse: texture
}
components: [cubeMesh, cubeTransform, material]
}
}
I have the following result :

Answer 2

You need to define some light source for your scene.
These are some example for Directional and Point lights:
DirectionalLight {
id: directionalLight
x: -0
y: 828.821
color: "#e0eef0"
shadowMapQuality: Light.ShadowMapQualityMedium
shadowFactor: 58
castsShadow: true
eulerRotation.z: 43.68403
eulerRotation.y: -57.35873
eulerRotation.x: -35.78494
z: 1415.04834
brightness: 80
}
PointLight {
id: lightPoint
x: -7.983
y: 737.434
shadowFactor: 4
castsShadow: true
brightness: 122
quadraticFade: 0.19392
z: 108.31305
}
You can move your lights or rotate the lights direction with changing the x, y and defining rotation values.