protected void SubmitFrame()
{
if (!_framePrepared)
{
throw new Exception("PrepareFrameCapture must be called before rendering when submitting a frame.");
}
_frameSubmitted = true;
// release the rendertarget so GetData does not fail
gd.SetRenderTarget(null);
var capturedFrame = _captureRenderTarget.ToPixelData();
_submittedFrames.Add(capturedFrame);
gd.SetRenderTarget(_captureRenderTarget);
}