source/blender/nodes/shader/CMakeLists.txt

@@ -165,6 +165,7 @@ if(WITH_MATERIALX)
     materialx/nodes/huesatval.cc
     materialx/nodes/invert.cc
     materialx/nodes/light_falloff.cc
+    materialx/nodes/light_path.cc
     materialx/nodes/map_range.cc
     materialx/nodes/math.cc
     materialx/nodes/mix_rgb.cc

source/blender/nodes/shader/materialx/nodes/light_falloff.cc

@@ -11,7 +11,8 @@ NodeItem LightFalloffNodeParser::compute()
   NodeItem strength = get_input_value("Strength", NodeItem::Type::Float);
   NodeItem smooth = get_input_value("Smooth", NodeItem::Type::Float);
 
-  /* This node isn't supported by MaterialX. This formula was given from OSL shader code in Cycles node_light_falloff.osl. Considered ray_length=1.0f. */
+  /* This node isn't supported by MaterialX. This formula was given from OSL shader code in Cycles
+   * node_light_falloff.osl. Considered ray_length=1.0f. */
   strength = strength * val(1.0f) / (smooth + val(1.0f));
 
   return strength;

source/blender/nodes/shader/materialx/nodes/light_path.cc

@@ -0,0 +1,21 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "node_parser.h"
+
+namespace blender::nodes::materialx {
+
+NodeItem LightPathNodeParser::compute()
+{
+  /* This node isn't supported by MaterialX. Only default values returned. */
+  if (STREQ(socket_out_->name, "Is Camera Ray")) {
+    return val(1.0f);
+  }
+  if (STREQ(socket_out_->name, "Ray Length")) {
+    return val(1.0f);
+  }
+  return val(0.0f);
+}
+
+}  // namespace blender::nodes::materialx

source/blender/nodes/shader/materialx/nodes/node_parser.cc

@@ -158,6 +158,7 @@ NodeItem NodeParser::get_input_link(const bNodeSocket &socket, NodeItem::Type to
     CASE_NODE_TYPE(SH_NODE_HUE_SAT, HueSatValNodeParser)
     CASE_NODE_TYPE(SH_NODE_INVERT, InvertNodeParser)
     CASE_NODE_TYPE(SH_NODE_LIGHT_FALLOFF, LightFalloffNodeParser)
+    CASE_NODE_TYPE(SH_NODE_LIGHT_PATH, LightPathNodeParser)
     CASE_NODE_TYPE(SH_NODE_MAP_RANGE, MapRangeNodeParser)
     CASE_NODE_TYPE(SH_NODE_MATH, MathNodeParser)
     CASE_NODE_TYPE(SH_NODE_MIX_RGB_LEGACY, MixRGBNodeParser)

source/blender/nodes/shader/materialx/nodes/node_parser.h

@@ -100,6 +100,7 @@ DECLARE_NODE_PARSER(GammaNodeParser)
 DECLARE_NODE_PARSER(HueSatValNodeParser)
 DECLARE_NODE_PARSER(InvertNodeParser)
 DECLARE_NODE_PARSER(LightFalloffNodeParser)
+DECLARE_NODE_PARSER(LightPathNodeParser)
 DECLARE_NODE_PARSER(MapRangeNodeParser)
 DECLARE_NODE_PARSER(MathNodeParser)
 DECLARE_NODE_PARSER(MixRGBNodeParser)