1 files changed, 16 insertions, 5 deletions
diff --git a/intern/cycles/render/session.cpp b/intern/cycles/render/session.cpp
index acf9ca68889..ae0a2cf863a 100644
--- a/intern/cycles/render/session.cpp
+++ b/intern/cycles/render/session.cpp
@@ -908,9 +908,6 @@ void Session::set_samples(int samples)
     params.samples = samples;
     tile_manager.set_samples(samples);
 
-    {
-      thread_scoped_lock pause_lock(pause_mutex);
-    }
     pause_cond.notify_all();
   }
 }
@@ -946,6 +943,15 @@ void Session::set_denoising(bool denoising, bool optix_denoising)
   tile_manager.schedule_denoising = denoising && !buffers;
 }
 
+void Session::set_denoising_start_sample(int sample)
+{
+  if (sample != params.denoising_start_sample) {
+    params.denoising_start_sample = sample;
+
+    pause_cond.notify_all();
+  }
+}
+
 void Session::wait()
 {
   if (session_thread) {
@@ -1110,8 +1116,8 @@ void Session::denoise()
     return;
   }
 
-  /* It can happen that denoising was already enabled, but the scene still needs an update. */
-  if (scene->film->need_update || !scene->film->denoising_data_offset) {
+  /* Do not denoise viewport until the sample at which denoising should start is reached. */
+  if (!params.background && tile_manager.state.sample < params.denoising_start_sample) {
     return;
   }
 
@@ -1122,6 +1128,11 @@ void Session::denoise()
     return;
   }
 
+  /* It can happen that denoising was already enabled, but the scene still needs an update. */
+  if (scene->film->need_update || !scene->film->denoising_data_offset) {
+    return;
+  }
+
   /* Add separate denoising task. */
   DeviceTask task(DeviceTask::DENOISE);