4 files changed, 13 insertions, 0 deletions
diff --git a/intern/cycles/blender/addon/properties.py b/intern/cycles/blender/addon/properties.py
index c60881f9351..d66a1f70c48 100644
--- a/intern/cycles/blender/addon/properties.py
+++ b/intern/cycles/blender/addon/properties.py
@@ -569,6 +569,12 @@ class CyclesRenderSettings(bpy.types.PropertyGroup):
         default=64,
         subtype='PIXEL'
     )
+    preview_denoising_start_sample: IntProperty(
+        name="Start Denoising",
+        description="Sample to start denoising the preview at",
+        min=0, max=(1 << 24),
+        default=1,
+    )
 
     debug_reset_timeout: FloatProperty(
         name="Reset timeout",
diff --git a/intern/cycles/blender/addon/ui.py b/intern/cycles/blender/addon/ui.py
index 3efd2a0c209..ed9e3a4c9cf 100644
--- a/intern/cycles/blender/addon/ui.py
+++ b/intern/cycles/blender/addon/ui.py
@@ -710,6 +710,11 @@ class CYCLES_RENDER_PT_performance_viewport(CyclesButtonsPanel, Panel):
         col.prop(rd, "preview_pixel_size", text="Pixel Size")
         col.prop(cscene, "preview_start_resolution", text="Start Pixels")
 
+        if show_optix_denoising(context):
+            sub = col.row(align=True)
+            sub.active = cscene.preview_denoising != 'NONE'
+            sub.prop(cscene, "preview_denoising_start_sample", text="Denoising Start Sample")
+
 
 class CYCLES_RENDER_PT_filter(CyclesButtonsPanel, Panel):
     bl_label = "Filter"
diff --git a/intern/cycles/blender/blender_session.cpp b/intern/cycles/blender/blender_session.cpp
index 388af80a79a..5cfb1200c7c 100644
--- a/intern/cycles/blender/blender_session.cpp
+++ b/intern/cycles/blender/blender_session.cpp
@@ -849,6 +849,7 @@ void BlenderSession::synchronize(BL::Depsgraph &b_depsgraph_)
 
   /* increase samples, but never decrease */
   session->set_samples(session_params.samples);
+  session->set_denoising_start_sample(session_params.denoising_start_sample);
   session->set_pause(session_pause);
 
   /* copy recalc flags, outside of mutex so we can decide to do the real
diff --git a/intern/cycles/blender/blender_sync.cpp b/intern/cycles/blender/blender_sync.cpp
index bfa3df1b295..50442c6ebdc 100644
--- a/intern/cycles/blender/blender_sync.cpp
+++ b/intern/cycles/blender/blender_sync.cpp
@@ -832,6 +832,7 @@ SessionParams BlenderSync::get_session_params(BL::RenderEngine &b_engine,
 
   /* other parameters */
   params.start_resolution = get_int(cscene, "preview_start_resolution");
+  params.denoising_start_sample = get_int(cscene, "preview_denoising_start_sample");
   params.pixel_size = b_engine.get_preview_pixel_size(b_scene);
 
   /* other parameters */