message: set optSPP on renderer
diff: @@ -280,11 +280,7 @@ void BatchContext::render()
  frame->child("navMode") = false;
  - // Accumulate several frames
  - for (auto i = 0; i < optSPP - 1; i++) {
  - frame->immediatelyWait = true;
  - frame->startNewFrame();
  - }
  + frame->child("renderer").child("pixelSamples").setValue(optSPP);
  // Only denoise the final frame
  // XXX TODO if optDenoiser == 2, save both the noisy and denoised color
  