From 40c58cc31495d09bec6d2896b5eefd0a5e5ac156 Mon Sep 17 00:00:00 2001
From: Ben Houston <neuralsoft@gmail.com>
Date: Mon, 11 May 2026 12:36:33 -0400
Subject: [PATCH 1/2] fix: smoothstep should emulate glsl behavior in
 degenerate cases

---
 libraries/stdlib/genosl/stdlib_genosl_impl.mtlx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/stdlib/genosl/stdlib_genosl_impl.mtlx b/libraries/stdlib/genosl/stdlib_genosl_impl.mtlx
index 345974e95c..1f9c3fe75f 100644
--- a/libraries/stdlib/genosl/stdlib_genosl_impl.mtlx
+++ b/libraries/stdlib/genosl/stdlib_genosl_impl.mtlx
@@ -543,7 +543,7 @@
   <implementation name="IM_remap_vector4FA_genosl" nodedef="ND_remap_vector4FA" target="genosl" sourcecode="mx_remap({{in}}, {{inlow}}, {{inhigh}}, {{outlow}}, {{outhigh}}, 0)" />
 
   <!-- <smoothstep> -->
-  <implementation name="IM_smoothstep_float_genosl" nodedef="ND_smoothstep_float" target="genosl" sourcecode="smoothstep({{low}}, {{high}}, {{in}})" />
+  <implementation name="IM_smoothstep_float_genosl" nodedef="ND_smoothstep_float" target="genosl" sourcecode="mx_ternary({{high}} > {{low}}, smoothstep({{low}}, {{high}}, {{in}}), mx_ternary({{in}} < {{high}}, 0.0, 1.0))" />
   <implementation name="IM_smoothstep_vector2_genosl" nodedef="ND_smoothstep_vector2" target="genosl" sourcecode="smoothstep({{low}}, {{high}}, {{in}})" />
   <implementation name="IM_smoothstep_vector3_genosl" nodedef="ND_smoothstep_vector3" target="genosl" sourcecode="smoothstep({{low}}, {{high}}, {{in}})" />
   <implementation name="IM_smoothstep_vector4_genosl" nodedef="ND_smoothstep_vector4" target="genosl" sourcecode="smoothstep({{low}}, {{high}}, {{in}})" />

From bbe7d5a484aa8754d2cb1ece4a445023a20a3fb8 Mon Sep 17 00:00:00 2001
From: Ben Houston <neuralsoft@gmail.com>
Date: Mon, 11 May 2026 21:25:51 -0400
Subject: [PATCH 2/2] Extend OSL smoothstep degenerate handling to vector types

Apply the inverted/degenerate smoothstep fallback component-wise for vector2, vector3, and vector4 to match the float fix across all smoothstep nodedef variants.
---
 libraries/stdlib/genosl/stdlib_genosl_impl.mtlx | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/libraries/stdlib/genosl/stdlib_genosl_impl.mtlx b/libraries/stdlib/genosl/stdlib_genosl_impl.mtlx
index 1f9c3fe75f..fe444a25bb 100644
--- a/libraries/stdlib/genosl/stdlib_genosl_impl.mtlx
+++ b/libraries/stdlib/genosl/stdlib_genosl_impl.mtlx
@@ -544,9 +544,9 @@
 
   <!-- <smoothstep> -->
   <implementation name="IM_smoothstep_float_genosl" nodedef="ND_smoothstep_float" target="genosl" sourcecode="mx_ternary({{high}} > {{low}}, smoothstep({{low}}, {{high}}, {{in}}), mx_ternary({{in}} < {{high}}, 0.0, 1.0))" />
-  <implementation name="IM_smoothstep_vector2_genosl" nodedef="ND_smoothstep_vector2" target="genosl" sourcecode="smoothstep({{low}}, {{high}}, {{in}})" />
-  <implementation name="IM_smoothstep_vector3_genosl" nodedef="ND_smoothstep_vector3" target="genosl" sourcecode="smoothstep({{low}}, {{high}}, {{in}})" />
-  <implementation name="IM_smoothstep_vector4_genosl" nodedef="ND_smoothstep_vector4" target="genosl" sourcecode="smoothstep({{low}}, {{high}}, {{in}})" />
+  <implementation name="IM_smoothstep_vector2_genosl" nodedef="ND_smoothstep_vector2" target="genosl" sourcecode="vector2(mx_ternary({{high}}.x &gt; {{low}}.x, smoothstep({{low}}.x, {{high}}.x, {{in}}.x), mx_ternary({{in}}.x &lt; {{high}}.x, 0.0, 1.0)), mx_ternary({{high}}.y &gt; {{low}}.y, smoothstep({{low}}.y, {{high}}.y, {{in}}.y), mx_ternary({{in}}.y &lt; {{high}}.y, 0.0, 1.0)))" />
+  <implementation name="IM_smoothstep_vector3_genosl" nodedef="ND_smoothstep_vector3" target="genosl" sourcecode="vector(mx_ternary({{high}}.x &gt; {{low}}.x, smoothstep({{low}}.x, {{high}}.x, {{in}}.x), mx_ternary({{in}}.x &lt; {{high}}.x, 0.0, 1.0)), mx_ternary({{high}}.y &gt; {{low}}.y, smoothstep({{low}}.y, {{high}}.y, {{in}}.y), mx_ternary({{in}}.y &lt; {{high}}.y, 0.0, 1.0)), mx_ternary({{high}}.z &gt; {{low}}.z, smoothstep({{low}}.z, {{high}}.z, {{in}}.z), mx_ternary({{in}}.z &lt; {{high}}.z, 0.0, 1.0)))" />
+  <implementation name="IM_smoothstep_vector4_genosl" nodedef="ND_smoothstep_vector4" target="genosl" sourcecode="vector4(mx_ternary({{high}}.x &gt; {{low}}.x, smoothstep({{low}}.x, {{high}}.x, {{in}}.x), mx_ternary({{in}}.x &lt; {{high}}.x, 0.0, 1.0)), mx_ternary({{high}}.y &gt; {{low}}.y, smoothstep({{low}}.y, {{high}}.y, {{in}}.y), mx_ternary({{in}}.y &lt; {{high}}.y, 0.0, 1.0)), mx_ternary({{high}}.z &gt; {{low}}.z, smoothstep({{low}}.z, {{high}}.z, {{in}}.z), mx_ternary({{in}}.z &lt; {{high}}.z, 0.0, 1.0)), mx_ternary({{high}}.w &gt; {{low}}.w, smoothstep({{low}}.w, {{high}}.w, {{in}}.w), mx_ternary({{in}}.w &lt; {{high}}.w, 0.0, 1.0)))" />
 
   <!-- <luminance> -->
   <implementation name="IM_luminance_color3_genosl" nodedef="ND_luminance_color3" file="mx_luminance_color3.osl" function="mx_luminance_color3" target="genosl" />