Kuesa provides support for reflection planes provided in glTF files through a custom glTF extension.

Adding Reflection Planes to a glTF scene

Using Blender

Assuming the Kuesa Studio Blender addon has been installed, the use of Reflection plane is straightforward.

Adding a Reflection Plane

In Blender, reflection planes are found unded the Light Probe section.

Previewing Reflections

Once the plane has been positioned and scaled, make sure to select the Rendered Viewport Shading.

Next, go to the Object Data Properties tab of the Reflection Plane and enable the Show Preview Plane checkbox.

Exporting Reflection Planes

To export reflection planes, you only need to ensure that the KDAB_kuesa_reflection_planes extension has been selected in the export dialog.

Retrieving Reflection Planes

When loading a glTF file using the GLTF2Importer referencing a SceneEntity, all reflection planes found while parsing while be added to the ReflectionPlaneCollection of the scene entity.

This then allows retrieving the ReflectionPlane instances by name, either directly from the ReflectionPlaneCollection if using C++ or though the use of the Asset element in QML.

C++

 Kuesa::SceneEntity *sceneEntity = new Kuesa::SceneEntity();
 Kuesa::GLTF2Importer *importer = new Kuesa::GLTF2Importer();

 QObject::connect(sceneEntity, Kuesa::SceneEntity::loadingDone, [&] () {
     Kuesa::ReflectionPlane *plane = sceneEntity->reflectionPlane("ReflectionPlane");
     ...
 });

 importer->setSceneEntity(sceneEntity);
 importer->setSource(QUrl("file:///reflections.gltf"));

QML

 import Kuesa 1.3 as Kuesa

 Kuesa.SceneEntity {
     id: scene
     ...
     Kuesa.GLTF2Importer {
         id: gltf2importer
         sceneEntity: scene
         source: "file:///reflections.gltf"
     }
     Kuesa.Asset {
         id: sceneReflectionPlane
         collection: scene.reflectionPlanes
         name: "ReflectionPlane"
     }
 }

Configuring the Forward Renderer for Reflections

Once retrieved, the Kuesa::ReflectionPlane can be set on either the ForwardRenderer or the View instances defined in the framegraph.

It should then be rendered. Please note however that for more advanced cases, using Layers in conjunction with Views can give you more control on the order in which rendering takes place. For instance, you might want to render the reflections after having rendered a background plane.

C++

 Kuesa::SceneEntity *sceneEntity = new Kuesa::SceneEntity();
 Kuesa::ForwardRenderer *renderer = new Kuesa::ForwardRenderer();
 Kuesa::GLTF2Importer *importer = new Kuesa::GLTF2Importer();

 QObject::connect(sceneEntity, Kuesa::SceneEntity::loadingDone, [&] () {
     Kuesa::ReflectionPlane *plane = sceneEntity->reflectionPlane("ReflectionPlane");
     renderer->addReflectionPlane(plane);
     ...
 });
 ...

QML

 import Kuesa 1.3 as Kuesa

 Kuesa.SceneEntity {
     id: scene
     ...
     components: [
         RenderSettings {
             activeFrameGraph: Kuesa.ForwardRenderer {
                 id: frameGraph
                 reflectionPlanes: [sceneReflectionPlane.node]
             }
         }
      ]
     ...
     Kuesa.Asset {
         id: sceneReflectionPlane
         collection: scene.reflectionPlanes
         name: "ReflectionPlane"
     }
 }