@babylonjs/core/FrameGraph/frameGraphUtils.js

Getting started? Play directly with the Babylon.js API using our [playground](https://playground.babylonjs.com/). It also contains a lot of samples to learn how to use it.

import { FrameGraphObjectRendererTask } from "./Tasks/Rendering/objectRendererTask.js";
import { FrameGraphGeometryRendererTask } from "./Tasks/Rendering/geometryRendererTask.js";
import { FrameGraphUtilityLayerRendererTask } from "./Tasks/Rendering/utilityLayerRendererTask.js";
import { UtilityLayerRenderer } from "../Rendering/utilityLayerRenderer.js";
/**
 * Looks for the main camera used by the frame graph.
 * By default, this is the camera used by the main object renderer task.
 * If no such task, we try to find a camera in either a geometry renderer or a utility layer renderer tasks.
 * @param frameGraph The frame graph to search in
 * @returns The main camera used by the frame graph, or null if not found
 */
export function FindMainCamera(frameGraph) {
    const mainObjectRenderer = FrameGraphUtils.FindMainObjectRenderer(frameGraph);
    if (mainObjectRenderer) {
        return mainObjectRenderer.camera;
    }
    // Try to find a camera in either the geometry renderer or the utility layer renderer tasks
    const tasks = frameGraph.tasks;
    for (let i = tasks.length - 1; i >= 0; i--) {
        const task = tasks[i];
        if (task instanceof FrameGraphGeometryRendererTask || task instanceof FrameGraphUtilityLayerRendererTask) {
            return task.camera;
        }
    }
    return null;
}
/**
 * Looks for the main object renderer task in the frame graph.
 * By default, this is the object renderer task with isMainObjectRenderer set to true.
 * If no such task, we return the last object renderer task that has an object list with meshes (or null if none found).
 * @param frameGraph The frame graph to search in
 * @returns The main object renderer of the frame graph, or null if not found
 */
export function FindMainObjectRenderer(frameGraph) {
    const objectRenderers = frameGraph.getTasksByType(FrameGraphObjectRendererTask);
    let fallbackRenderer = null;
    for (let i = objectRenderers.length - 1; i >= 0; --i) {
        if (objectRenderers[i].isMainObjectRenderer) {
            return objectRenderers[i];
        }
        if (objectRenderers[i].objectList.meshes && !fallbackRenderer) {
            fallbackRenderer = objectRenderers[i];
        }
    }
    return fallbackRenderer;
}
/**
 * Creates a utility layer renderer compatible with the given frame graph.
 * @param frameFraph The frame graph to create the utility layer renderer for
 * @param handleEvents True if the utility layer renderer should handle events, false otherwise (default is true)
 * @returns The created utility layer renderer
 */
export function CreateUtilityLayerRenderer(frameFraph, handleEvents = true) {
    const scene = frameFraph.scene;
    const layer = new UtilityLayerRenderer(scene, handleEvents, true);
    layer.utilityLayerScene.activeCamera = scene.activeCamera;
    let camera = FrameGraphUtils.FindMainCamera(scene.frameGraph);
    if (!camera && scene.cameras.length > 0) {
        camera = scene.cameras[0];
    }
    if (camera) {
        layer.setRenderCamera(camera);
        layer.utilityLayerScene.activeCamera = camera;
    }
    const gizmoLayerRenderObserver = scene.onAfterRenderObservable.add(() => {
        layer.render();
    });
    layer.utilityLayerScene.onDisposeObservable.addOnce(() => {
        scene.onAfterRenderObservable.remove(gizmoLayerRenderObserver);
    });
    return layer;
}
/**
 * Class used to host frame graph specific utilities
 */
export const FrameGraphUtils = {
    /**
     * Looks for the main camera used by the frame graph.
     * We assume that the camera used by the the last rendering task in the graph is the main camera.
     * @param frameGraph The frame graph to search in
     * @returns The main camera used by the frame graph, or null if not found
     */
    FindMainCamera,
    /**
     * Looks for the main object renderer task in the frame graph.
     * We assume that the last object renderer task that has an object list with meshes is the main object renderer.
     * @param frameGraph The frame graph to search in
     * @returns The main object renderer of the frame graph, or null if not found
     */
    FindMainObjectRenderer,
    /**
     * Creates a utility layer renderer compatible with the given frame graph.
     * @param frameFraph The frame graph to create the utility layer renderer for
     * @param handleEvents True if the utility layer renderer should handle events, false otherwise
     * @returns The created utility layer renderer
     */
    CreateUtilityLayerRenderer,
};
//# sourceMappingURL=frameGraphUtils.js.map