Initial commit legacy materials

contrib/adsk/libraries/adsklib/genglsl/adsklib_genglsl_impl.mtlx

@@ -7,4 +7,8 @@
   -->
   <!-- <backface_util> -->
   <implementation name="IM_backface_util_genglsl" nodedef="adsk:ND_backface_util" file="mx_backface_util.glsl" function="mx_backface_util" target="genglsl"/>
+
+  <implementation name="IM_turbulence2d_float_genglsl" nodedef="ND_turbulence2d_float" file="mx_turbulence2d_float.glsl" function="mx_turbulence2d_float" target="genglsl" />
+  <implementation name="IM_turbulence3d_float_genglsl" nodedef="ND_turbulence3d_float" file="mx_turbulence3d_float.glsl" function="mx_turbulence3d_float" target="genglsl" />
+
 </materialx>

contrib/adsk/libraries/adsklib/genglsl/mx_turbulence2d_float.glsl

@@ -0,0 +1,23 @@
+#include "../../stdlib/genglsl/lib/mx_noise.glsl"
+
+void mx_turbulence2d_float(float amplitude, float octaves, vec2 texcoord, out float result)
+{
+    float sum = 0.0;
+    float scale = 1.0;
+
+    // Accumulate the required number of octaves of noise.
+    float i = 0.0;
+    for (i = octaves; i >= 1.0; i -= 1.0) {
+        float value = mx_perlin_noise_float(texcoord * scale) / scale;
+        sum += abs(value);
+        scale *= 2.0;
+    }
+
+    // Add a portion of the remaining octave, if any.
+    if (i > 0.0) {
+        float value = mx_perlin_noise_float(texcoord * scale) / scale;
+        sum += abs(value) * i;
+    }
+
+	result = sum * amplitude;
+}

contrib/adsk/libraries/adsklib/genglsl/mx_turbulence3d_float.glsl

@@ -0,0 +1,23 @@
+#include "../../stdlib/genglsl/lib/mx_noise.glsl"
+
+void mx_turbulence3d_float(float amplitude, float octaves, vec3 position, out float result)
+{
+    float sum = 0.0;
+    float scale = 1.0;
+
+    // Accumulate the required number of octaves of noise.
+    float i = 0.0;
+    for (i = octaves; i >= 1.0; i -= 1.0) {
+        float value = mx_perlin_noise_float(position * scale) / scale;
+        sum += abs(value);
+        scale *= 2.0;
+    }
+
+    // Add a portion of the remaining octave, if any.
+    if (i > 0.0) {
+        float value = mx_perlin_noise_float(position * scale) / scale;
+        sum += abs(value) * i;
+    }
+
+	result = sum * amplitude;
+}