Fix T78692: improve UI regarding the effect of the denoiser on denoising passes

It wasn't obvious that the choice of Cycles denoiser also generates different
denoising data passes for compositing.

intern/cycles/blender/addon/engine.py

@@ -224,7 +224,7 @@ def system_info():
     import _cycles
     return _cycles.system_info()
 
-def list_render_passes(srl):
+def list_render_passes(scene, srl):
     # Builtin Blender passes.
     yield ("Combined", "RGBA", 'COLOR')
 
@@ -279,14 +279,17 @@ def list_render_passes(srl):
             yield ("Denoising Normal",          "XYZ", 'VECTOR')
             yield ("Denoising Albedo",          "RGB", 'COLOR')
             yield ("Denoising Depth",           "Z",   'VALUE')
-            yield ("Denoising Shadowing",       "X",   'VALUE')
-            yield ("Denoising Variance",        "RGB", 'COLOR')
-            yield ("Denoising Intensity",       "X",   'VALUE')
-            clean_options = ("denoising_diffuse_direct", "denoising_diffuse_indirect",
-                             "denoising_glossy_direct", "denoising_glossy_indirect",
-                             "denoising_transmission_direct", "denoising_transmission_indirect")
-            if any(getattr(crl, option) for option in clean_options):
-                yield ("Denoising Clean", "RGB", 'COLOR')
+
+            if scene.cycles.denoiser == 'NLM':
+                yield ("Denoising Shadowing",       "X",   'VALUE')
+                yield ("Denoising Variance",        "RGB", 'COLOR')
+                yield ("Denoising Intensity",       "X",   'VALUE')
+
+                clean_options = ("denoising_diffuse_direct", "denoising_diffuse_indirect",
+                                 "denoising_glossy_direct", "denoising_glossy_indirect",
+                                 "denoising_transmission_direct", "denoising_transmission_indirect")
+                if any(getattr(crl, option) for option in clean_options):
+                    yield ("Denoising Clean", "RGB", 'COLOR')
 
     # Custom AOV passes.
     for aov in crl.aovs:
@@ -298,15 +301,15 @@ def list_render_passes(srl):
 def register_passes(engine, scene, view_layer):
     # Detect duplicate render pass names, first one wins.
     listed = set()
-    for name, channelids, channeltype in list_render_passes(view_layer):
+    for name, channelids, channeltype in list_render_passes(scene, view_layer):
         if name not in listed:
             engine.register_pass(scene, view_layer, name, len(channelids), channelids, channeltype)
             listed.add(name)
 
-def detect_conflicting_passes(view_layer):
+def detect_conflicting_passes(scene, view_layer):
     # Detect conflicting render pass names for UI.
     counter = {}
-    for name, _, _ in list_render_passes(view_layer):
+    for name, _, _ in list_render_passes(scene, view_layer):
         counter[name] = counter.get(name, 0) + 1
 
     for aov in view_layer.cycles.aovs:

intern/cycles/blender/addon/properties.py

@@ -182,6 +182,7 @@ enum_aov_types = (
     ('COLOR', "Color", "Write a Color pass", 1),
 )
 
+
 def enum_openimagedenoise_denoiser(self, context):
     if _cycles.with_openimagedenoise:
         return [('OPENIMAGEDENOISE', "OpenImageDenoise", "Use Intel OpenImageDenoise AI denoiser running on the CPU", 4)]
@@ -216,6 +217,14 @@ enum_denoising_optix_input_passes = (
     ('RGB_ALBEDO_NORMAL', "Color + Albedo + Normal", "Use color, albedo and normal data as input", 3),
 )
 
+
+def update_render_passes(self, context):
+    scene = context.scene
+    view_layer = context.view_layer
+    view_layer.update_render_passes()
+    engine.detect_conflicting_passes(scene, view_layer)
+
+
 class CyclesRenderSettings(bpy.types.PropertyGroup):
 
     device: EnumProperty(
@@ -261,9 +270,12 @@ class CyclesRenderSettings(bpy.types.PropertyGroup):
 
     denoiser: EnumProperty(
         name="Denoiser",
-        description="Denoise the image with the selected denoiser",
+        description="Denoise the image with the selected denoiser. "
+        "For denoising the image after rendering, denoising data render passes "
+        "also adapt to the selected denoiser.",
         items=enum_denoiser,
         default=1,
+        update=update_render_passes,
     )
     preview_denoiser: EnumProperty(
         name="Viewport Denoiser",
@@ -1291,12 +1303,6 @@ class CyclesCurveRenderSettings(bpy.types.PropertyGroup):
         del bpy.types.Scene.cycles_curves
 
 
-def update_render_passes(self, context):
-    view_layer = context.view_layer
-    view_layer.update_render_passes()
-    engine.detect_conflicting_passes(view_layer)
-
-
 class CyclesAOVPass(bpy.types.PropertyGroup):
     name: StringProperty(
         name="Name",
@@ -1430,7 +1436,7 @@ class CyclesRenderLayerSettings(bpy.types.PropertyGroup):
     )
     denoising_store_passes: BoolProperty(
         name="Store Denoising Passes",
-        description="Store the denoising feature passes and the noisy image",
+        description="Store the denoising feature passes and the noisy image. The passes adapt to the denoiser selected for rendering",
         default=False,
         update=update_render_passes,
     )

intern/cycles/blender/addon/ui.py

@@ -265,7 +265,12 @@ class CYCLES_RENDER_PT_sampling_denoising(CyclesButtonsPanel, Panel):
         row = heading.row(align=True)
         row.prop(cscene, "use_denoising", text="")
         sub = row.row()
+
         sub.active = cscene.use_denoising
+        for view_layer in scene.view_layers:
+            if view_layer.cycles.denoising_store_passes:
+                sub.active = True
+
         sub.prop(cscene, "denoiser", text="")
 
         heading = layout.column(align=False, heading="Viewport")