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PickingManager

PickingManager manages an offscreen picking framebuffer and the shader-input updates needed for luma.gl's picking shader module.

It is useful when rendering models with picking uniforms and reading back the selected object and batch ids.

Usage​

import {PickingManager, ShaderInputs} from '@luma.gl/engine';
import {pickingUniforms} from '@luma.gl/engine/modules/picking/picking-uniforms';

const shaderInputs = new ShaderInputs({picking: pickingUniforms});
const pickingManager = new PickingManager(device, {shaderInputs});

Types​

PickInfo​

export type PickInfo = {
  batchIndex: number | null;
  objectIndex: number | null;
};

PickingManagerProps​

export type PickingManagerProps = {
  shaderInputs?: ShaderInputs<{picking: typeof pickingUniforms.props}>;
  onObjectPicked?: (info: PickInfo) => void;
};

Properties​

pickInfo​

Latest picked batch and object indices.

framebuffer​

Framebuffer used for picking readback.

Methods​

constructor(device: Device, props: PickingManagerProps)​

Creates a picking manager for one device.

destroy(): void​

Destroys the picking framebuffer.

getFramebuffer(): Framebuffer​

Returns the picking framebuffer, creating it lazily when needed.

clearPickState(): void​

Clears the highlighted object state in the attached ShaderInputs.

beginRenderPass()​

Begins a render pass that writes picking data into the picking framebuffer.

updatePickInfo(mousePosition: [number, number]): Promise<PickInfo | null>​

Reads back one picked pixel, updates shader inputs, and calls onObjectPicked when the pick result changes.

getPickPosition(mousePosition: [number, number]): [number, number]​

Converts CSS pixel mouse coordinates into device-pixel picking coordinates.