API Reference > imodeljs-frontend > Views > ViewManager > onBeginRender onBeginRender onBeginRender: BeEvent<() => void> = new BeEvent<() => void>() Called at the beginning of each tick of the render loop, before any viewports have been updated. The render loop is typically invoked by a requestAnimationFrame() callback. It will not be invoked if the ViewManager is tracking no viewports. note Due to the frequency of this event, avoid performing expensive work inside event listeners. see ViewManager.onFinishRender Defined in core/frontend/src/ViewManager.ts Line 136 Last Updated: 13 June, 2024