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Fix perlin and simplex noises to return normalized value to range 0-1

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#3154
This commit is contained in:
Wojtek Figat
2025-02-12 22:13:09 +01:00
parent 6efb015169
commit c146e156ec
3 changed files with 7 additions and 11 deletions
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4
Source/Engine/Utilities/Noise.cpp
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@@ -114,7 +114,7 @@ namespace
Float2 fade_xy = PerlinNoiseFade(Float2(Pf)); Float2 fade_xy = PerlinNoiseFade(Float2(Pf));
Float2 n_x = Float2::Lerp(Float2(n00, n01), Float2(n10, n11), fade_xy.X); Float2 n_x = Float2::Lerp(Float2(n00, n01), Float2(n10, n11), fade_xy.X);
float n_xy = Math::Lerp(n_x.X, n_x.Y, fade_xy.Y); float n_xy = Math::Lerp(n_x.X, n_x.Y, fade_xy.Y);
return Math::Saturate(2.3f * n_xy); return Math::Saturate(n_xy * 2.136f + 0.5f); // Rescale to [0;1]
} }
} }
@@ -169,7 +169,7 @@ float Noise::SimplexNoise(const Float2& p)
float gx = a0.X * x0.X + h.X * x0.Y; float gx = a0.X * x0.X + h.X * x0.Y;
Float2 gyz = Float2(a0.Y, a0.Z) * Float2(x12.X, x12.Z) + Float2(h.Y, h.Z) * Float2(x12.Y, x12.W); Float2 gyz = Float2(a0.Y, a0.Z) * Float2(x12.X, x12.Z) + Float2(h.Y, h.Z) * Float2(x12.Y, x12.W);
Float3 g(gx, gyz.X, gyz.Y); Float3 g(gx, gyz.X, gyz.Y);
return Math::Saturate(130.0f * Float3::Dot(m, g)); return Math::Saturate(Float3::Dot(m, g) * 71.428f + 0.5f); // Rescale to [0;1]
} }
Float2 Noise::WorleyNoise(const Float2& p) Float2 Noise::WorleyNoise(const Float2& p)

9
Source/Engine/Utilities/PerlinNoise.cs
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@@ -58,15 +58,13 @@ namespace FlaxEngine.Utilities
/// <param name="x">The x coordinate.</param> /// <param name="x">The x coordinate.</param>
/// <param name="y">The y coordinate.</param> /// <param name="y">The y coordinate.</param>
/// <returns>The noise value.</returns> /// <returns>The noise value.</returns>
public float Sample(int x, int y) public float Sample(float x, float y)
{ {
float noise = 0.0f; float noise = 0.0f;
if (NoiseScale > Mathf.Epsilon) if (NoiseScale > Mathf.Epsilon)
{ {
x = Math.Abs(x); x = Mathf.Abs(x);
y = Math.Abs(y); y = Mathf.Abs(y);
for (int octave = 0; octave < Octaves; octave++) for (int octave = 0; octave < Octaves; octave++)
{ {
float octaveShift = 1 << octave; float octaveShift = 1 << octave;
@@ -74,7 +72,6 @@ namespace FlaxEngine.Utilities
noise += PerlinNoise2D(x * octaveScale, y * octaveScale) / octaveShift; noise += PerlinNoise2D(x * octaveScale, y * octaveScale) / octaveShift;
} }
} }
return Base + noise * NoiseAmount; return Base + noise * NoiseAmount;
} }

5
Source/Shaders/Noise.hlsl
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@@ -89,7 +89,6 @@ float3 rand3dTo3d(float3 value)
); );
} }
float PerlinNoiseImpl(float4 Pi, float4 Pf) float PerlinNoiseImpl(float4 Pi, float4 Pf)
{ {
Pi = Mod289(Pi); Pi = Mod289(Pi);
@@ -124,7 +123,7 @@ float PerlinNoiseImpl(float4 Pi, float4 Pf)
float2 fade_xy = PerlinNoiseFade(Pf.xy); float2 fade_xy = PerlinNoiseFade(Pf.xy);
float2 n_x = lerp(float2(n00, n01), float2(n10, n11), fade_xy.x); float2 n_x = lerp(float2(n00, n01), float2(n10, n11), fade_xy.x);
float n_xy = lerp(n_x.x, n_x.y, fade_xy.y); float n_xy = lerp(n_x.x, n_x.y, fade_xy.y);
return saturate(2.3 * n_xy); return saturate(n_xy * 2.136f + 0.5f); // Rescale to [0;1]
} }
// Classic Perlin noise // Classic Perlin noise
@@ -183,7 +182,7 @@ float SimplexNoise(float2 p)
float gx = a0.x * x0.x + h.x * x0.y; float gx = a0.x * x0.x + h.x * x0.y;
float2 gyz = a0.yz * x12.xz + h.yz * x12.yw; float2 gyz = a0.yz * x12.xz + h.yz * x12.yw;
float3 g = float3(gx, gyz); float3 g = float3(gx, gyz);
return saturate(130.0f * dot(m, g)); return saturate(dot(m, g) * 71.428f + 0.5f); // Rescale to [0;1]
} }
// Worley noise (cellar noise with standard 3x3 search window for F1 and F2 values) // Worley noise (cellar noise with standard 3x3 search window for F1 and F2 values)