Shadow Mapping not working after porting to Qt 6,8

DavideCaldara

Hello!

I'm developing an application in QtQuick3D in which i'm rendering some Models and casting shadows from a DirectionalLight. After porting from Qt 6.7.2 to 6.8 shadowmapping does not work anymore. Does anyone know why? I already tried to set model properties castsShadows and receivesShadows to true but shadows are not showing at all.
This is my light.

DirectionalLight {
            id: light1
            eulerRotation.x: 45
            eulerRotation.y: -45
            // ShadowMapping
            castsShadow: true
            shadowMapQuality: Light.ShadowMapQualityVeryHigh
            shadowFactor: 75
            brightness: 0.75
            pcfFactor: 2.0
            softShadowQuality: Light.PCF4
        }

SGaist

Hi and welcome to devnet,

Sounds like a possible regression.
On which OS are you ?
Can you provide a minimal compilable reproducer ?

DavideCaldara

Thanks for the reply,
I'm using windows 11.
Here is an example qml file I have the issue with

import QtQuick3D
import QtQuick
import QtQuick3D.Helpers
import QtQuick.Controls
import QtQuick.Dialogs
import QtQuick.Layouts
import MyQMLItem

MyQMLItem {
    View3D {
        anchors.fill: parent
        environment: ExtendedSceneEnvironment {
            id: sceneEnvironment
            clearColor: "grey"
            backgroundMode: SceneEnvironment.Color

            // Anti-Aliasing
            antialiasingMode: SceneEnvironment.MSAA
            antialiasingQuality: SceneEnvironment.VeryHigh

            // Ambient Occlusion
            aoEnabled: false
            aoStrength: 100
            aoDistance: 20
            aoSampleRate: 4
            aoSoftness: 50
        }

        Node {
            id: rotationNode
            eulerRotation.x: 40
            eulerRotation.y: -40
            // Camera inside the rotation node to rotate around the center of the scene
            OrthographicCamera {
                id: camera
                z: 6000
                horizontalMagnification: 1.0
                verticalMagnification: 1.0
                clipNear: 10.0
                clipFar: 15000.0
            }
        }

        DirectionalLight {
            id: light1
            eulerRotation.x: 45
            eulerRotation.y: -45
            // ShadowMapping
            castsShadow: true
            shadowMapQuality: Light.ShadowMapQualityVeryHigh
            shadowFactor: 75
            brightness: 0.75
        }

        DirectionalLight {
            id: light2
            eulerRotation.x: -45
            eulerRotation.y: 45
            brightness: 0.75
        }

        Model {
            source: "#Cube"
            materials: DefaultMaterial {
                diffuseColor: "lightgreen"
            }
        }

        Model {
            source: "#Cube"
            scale: Qt.vector3d(5, 0.1, 5)
            position: Qt.vector3d(0, 100, 0)
            materials: DefaultMaterial {
                diffuseColor: "lightgreen"
            }
        }
    }
}

In Qt 6.7.2 I can see shadows (Desktop Qt 6.7.2 MSVC2019 64bit)

while in Qt 6.8 I don't see them (Desktop Qt 6.8.0 MSVC2022 64bit)

Jonas Karlsson

So there seems to actually be two bugs in one in this example. 1) The shadow mapping is invalid when using an orthographic camera and 2) When using two Directional lights the shadow seems to get painted over. I'll made two bug reports for them here: https://bugreports.qt.io/browse/QTBUG-132080 and https://bugreports.qt.io/browse/QTBUG-132081