warmUp method

Future<void> warmUp(List<RenderView> views)

Compiles the render pipelines and uploads the GPU resources this scene needs, by encoding one frame offscreen and discarding it, so the first visible frame does not stall while shaders compile or textures upload.

Pass the same views the scene will be shown with: their cameras, anti-aliasing, render targets, and this scene's lights and post-process settings determine which pipeline variants compile, so a warm-up frame must match the real one (the offscreen frame is rendered tiny, since a pipeline's identity does not depend on resolution). Populate the scene first; warm-up encodes whatever is attached when it runs.

A SceneView with warmUp: true calls this before it reveals the scene. Awaiting it is optional and safe to repeat. It awaits initializeStaticResources first. On backends that compile pipelines lazily on first draw (the common case) this front-loads that cost; on a backend that compiles asynchronously it kicks compilation off without blocking on completion.

Implementation

Future<void> warmUp(List<RenderView> views) async {
  await initializeStaticResources();
  if (views.isEmpty) {
    return;
  }
  // Advance a zero step so the warm-up frame does not move the scene's clock
  // forward before the first real frame (render then skips its implicit
  // wall-clock tick).
  update(0.0);
  // Encode one real frame into a discarded recording. The GPU passes (and so
  // the pipeline compilations and resource uploads) are submitted during
  // rendering; only the final canvas blit is thrown away. A small area is
  // enough because pipeline identity is resolution-independent.
  final recorder = ui.PictureRecorder();
  final canvas = ui.Canvas(recorder);
  renderViews(views, canvas, region: const ui.Rect.fromLTWH(0, 0, 64, 64));
  recorder.endRecording().dispose();
}