intern/cycles/scene/shader.cpp

@@ -153,6 +153,16 @@ static float3 output_estimate_emission(ShaderOutput *output, bool &is_constant)
       estimate *= node->get_float(strength_in->socket_type);
     }
 
+    /* Lower importance of emission nodes from automatic value/color to shader
+     * conversion, as these are likely used for previewing and can be slow to
+     * build a light tree for on dense meshes. */
+    if (node->type == EmissionNode::get_node_type()) {
+      EmissionNode *emission_node = static_cast<EmissionNode *>(node);
+      if (emission_node->from_auto_conversion) {
+        estimate *= 0.1f;
+      }
+    }
+
     return estimate;
   }
   else if (node->type == LightFalloffNode::get_node_type() ||

intern/cycles/scene/shader_graph.cpp

@@ -260,6 +260,7 @@ void ShaderGraph::connect(ShaderOutput *from, ShaderInput *to)
 
     if (to->type() == SocketType::CLOSURE) {
       EmissionNode *emission = create_node<EmissionNode>();
+      emission->from_auto_conversion = true;
       emission->set_color(one_float3());
       emission->set_strength(1.0f);
       convert = add(emission);

intern/cycles/scene/shader_nodes.h

@@ -723,6 +723,8 @@ class EmissionNode : public ShaderNode {
   NODE_SOCKET_API(float3, color)
   NODE_SOCKET_API(float, strength)
   NODE_SOCKET_API(float, surface_mix_weight)
+
+  bool from_auto_conversion = false;
 };
 
 class BackgroundNode : public ShaderNode {

source/blender/asset_system/AS_asset_identifier.hh

@@ -25,6 +25,7 @@ class AssetIdentifier {
   AssetIdentifier(const AssetIdentifier &) = default;
 
   std::string full_path() const;
+  std::string full_library_path() const;
 };
 
 }  // namespace blender::asset_system

source/blender/asset_system/AS_asset_representation.hh

@@ -92,7 +92,11 @@ class AssetRepresentation {
 /* C-Handle */
 struct AssetRepresentation;
 
-const std::string AS_asset_representation_full_path_get(const ::AssetRepresentation *asset);
+std::string AS_asset_representation_full_path_get(const ::AssetRepresentation *asset);
+/** Get the absolute path to the .blend file containing the given asset. String will be empty if
+ * the asset could not be mapped to a valid .blend file path. Valid in this case also means that
+ * the file needs to exist on disk. */
+std::string AS_asset_representation_full_library_path_get(const ::AssetRepresentation *asset);
 std::optional<eAssetImportMethod> AS_asset_representation_import_method_get(
     const ::AssetRepresentation *asset_handle);
 bool AS_asset_representation_may_override_import_method(const ::AssetRepresentation *asset_handle);

source/blender/asset_system/CMakeLists.txt

@@ -5,6 +5,7 @@ set(INC
   intern
   ../blenkernel
   ../blenlib
+  ../blenloader
   ../makesdna
   ../../../intern/clog
   ../../../intern/guardedalloc

source/blender/asset_system/intern/asset_identifier.cc

@@ -4,8 +4,11 @@
  * \ingroup asset_system
  */
 
+#include <string>
+
+#include "BLO_readfile.h"
+
 #include "BLI_path_util.h"
-#include <iostream>
 
 #include "AS_asset_identifier.hh"
 
@@ -24,4 +27,16 @@ std::string AssetIdentifier::full_path() const
   return path;
 }
 
+std::string AssetIdentifier::full_library_path() const
+{
+  std::string asset_path = full_path();
+
+  char blend_path[1090 /*FILE_MAX_LIBEXTRA*/];
+  if (!BLO_library_path_explode(asset_path.c_str(), blend_path, nullptr, nullptr)) {
+    return {};
+  }
+
+  return blend_path;
+}
+
 }  // namespace blender::asset_system

source/blender/asset_system/intern/asset_representation.cc

@@ -111,7 +111,7 @@ const AssetLibrary &AssetRepresentation::owner_asset_library() const
 
 using namespace blender;
 
-const std::string AS_asset_representation_full_path_get(const AssetRepresentation *asset_handle)
+std::string AS_asset_representation_full_path_get(const AssetRepresentation *asset_handle)
 {
   const asset_system::AssetRepresentation *asset =
       reinterpret_cast<const asset_system::AssetRepresentation *>(asset_handle);
@@ -119,6 +119,13 @@ const std::string AS_asset_representation_full_path_get(const AssetRepresentatio
   return identifier.full_path();
 }
 
+std::string AS_asset_representation_full_library_path_get(const AssetRepresentation *asset_handle)
+{
+  const asset_system::AssetRepresentation *asset =
+      reinterpret_cast<const asset_system::AssetRepresentation *>(asset_handle);
+  return asset->get_identifier().full_library_path();
+}
+
 std::optional<eAssetImportMethod> AS_asset_representation_import_method_get(
     const AssetRepresentation *asset_handle)
 {