Translate Mathf.PerlinNoise into shader

mgear · August 30, 2022, 8:53pm

unitys treeeditor perlinnoise source is available,

Unity-Technologies/UnityCsReference/blob/61f92bd79ae862c4465d35270f9d1d57befd1761/Modules/TreeEditor/Includes/Perlin.cs#L50


      
              {
                  if (s_Noise == null)
                      s_Noise = new FractalNoise(1.27F, 2.04F, 8.36F);
                  return s_Noise;
              }
          
              private static FractalNoise s_Noise;
          }
          
          
          public class Perlin
          {
              // Original C code derived from
              // http://astronomy.swin.edu.au/~pbourke/texture/perlin/perlin.c
              // http://astronomy.swin.edu.au/~pbourke/texture/perlin/perlin.h
              const int B = 0x100;
              const int BM = 0xff;
              const int N = 0x1000;
          
              int[] p = new int[B + B + 2];
              float[,] g3 = new float[B + B + 2, 3];

maybe its similar to mathf (which is not published…) ?

github.com

Unity-Technologies/UnityCsReference/blob/c84064be69f20dcf21ebe4a7bbc176d48e2f289c/Runtime/Export/Math/Math.bindings.cs#L115


      
          {
              [NativeMethod("IsInside", IsThreadSafe = true)] extern public bool Contains(Vector3 point);
              [FreeFunction("BoundsScripting::SqrDistance", HasExplicitThis = true, IsThreadSafe = true)] extern public float SqrDistance(Vector3 point);
              [FreeFunction("IntersectRayAABB", IsThreadSafe = true)] extern static private bool IntersectRayAABB(Ray ray, Bounds bounds, out float dist);
              [FreeFunction("BoundsScripting::ClosestPoint", HasExplicitThis = true, IsThreadSafe = true)] extern public Vector3 ClosestPoint(Vector3 point);
          }
          
          [NativeHeader("Runtime/Utilities/BitUtility.h")]
          [NativeHeader("Runtime/Math/ColorSpaceConversion.h")]
          [NativeHeader("Runtime/Math/FloatConversion.h")]
          [NativeHeader("Runtime/Math/PerlinNoise.h")]
          public partial struct Mathf
          {
              [FreeFunction(IsThreadSafe = true)] extern public static int  ClosestPowerOfTwo(int value);
              [FreeFunction(IsThreadSafe = true)] extern public static bool IsPowerOfTwo(int value);
              [FreeFunction(IsThreadSafe = true)] extern public static int  NextPowerOfTwo(int value);
          
              [FreeFunction(IsThreadSafe = true)] extern public static float GammaToLinearSpace(float value);
              [FreeFunction(IsThreadSafe = true)] extern public static float LinearToGammaSpace(float value);
              [FreeFunction(IsThreadSafe = true)] extern public static Color CorrelatedColorTemperatureToRGB(float kelvin);