Fix blackbody node clamping.

Author: nicolassavva-autodesk

libraries/pbrlib/genglsl/mx_blackbody.glsl

@@ -8,14 +8,13 @@ void mx_blackbody(float temperatureKelvin, out vec3 colorValue)
     float xc, yc;
     float t, t2, t3, xc2, xc3;
 
+    // if value outside valid range of approximation clamp to accepted temperature range
+    temperatureKelvin = clamp(temperatureKelvin, 1667.0, 25000.0);
+
     t = 1000.0 / temperatureKelvin;
     t2 = t * t;
     t3 = t * t * t;
 
-    // if value outside valid range of approximation clamp to accepted temperature range
-    clamp(temperatureKelvin, 1667.0, 25000.0);
-
-
     // Cubic spline approximation for Kelvin temperature to sRGB conversion
     // (https://en.wikipedia.org/wiki/Planckian_locus#Approximation)
     if (temperatureKelvin < 4000.0) {  // 1667K <= temperatureKelvin < 4000K

libraries/pbrlib/genosl/mx_blackbody.osl

@@ -3,14 +3,13 @@ void mx_blackbody(float temperature, output color color_value)
     float xc, yc;
     float t, t2, t3, xc2, xc3;
 
+    // if value outside valid range of approximation clamp to accepted temperature range
+    temperature = clamp(temperature, 1667.0, 25000.0);
+
     t = 1000.0 / temperature;
     t2 = t * t;
     t3 = t * t * t;
 
-    // if value outside valid range of approximation clamp to accepted temperature range
-    clamp(temperature, 1667.0, 25000.0);
-
-
     // Cubic spline approximation for Kelvin temperature to sRGB conversion
     // (https://en.wikipedia.org/wiki/Planckian_locus#Approximation)
     if (temperature < 4000.0) {  // 1667K <= temperature < 4000K