Fractal steel material

assets/materials/shaders/fractal_steel.gdshader

@@ -0,0 +1,103 @@
+// Voronoi fractal steel material
+// Based on https://www.shadertoy.com/view/4sl3Dr
+shader_type spatial;
+
+uniform vec2 uv_scale = vec2(1.0);
+uniform float edge_sharpness = 0.25;
+
+uniform vec3 base_color: source_color = vec3(1.0);
+
+uniform int octaves = 3;
+
+uniform float octave_dropoff = 0.7;
+uniform float octave_scale = 3.0;
+
+
+uniform float metallic = 1.0;
+uniform float roughness_scale = 1.0;
+uniform float bump_strength = 1.0;
+
+// 1D random numbers
+float rand(float n)
+{
+    return fract(sin(n) * 43758.5453123374897);
+}
+
+// 2D random numbers
+vec2 rand2(vec2 p)
+{
+	return fract(vec2(sin(p.x * 591.32 + p.y * 154.077), cos(p.x * 391.32 + p.y * 49.077)));
+}
+
+// 1D noise
+float noise1(float p)
+{
+	float fl = floor(p);
+	float fc = fract(p);
+	return mix(rand(fl), rand(fl + 1.0), fc);
+}
+
+// voronoi distance noise, based on iq's articles
+float voronoi(vec2 x)
+{
+	vec2 p = floor(x);
+	vec2 f = fract(x);
+	
+	vec2 res = vec2(8.0);
+	for(float j = -1.0; j <= 1.0; j ++)
+	{
+		for(float i = -1.0; i <= 1.0; i ++)
+		{
+			vec2 b = vec2(i, j);
+			vec2 r = vec2(b) - f + rand2(p + b);
+			
+			// chebyshev distance, one of many ways to do this
+			float d = max(abs(r.x), abs(r.y));
+			
+			if(d < res.x)
+			{
+				res.y = res.x;
+				res.x = d;
+			}
+			else if(d < res.y)
+			{
+				res.y = d;
+			}
+		}
+	}
+	return res.y - res.x;
+}
+
+void fragment() {
+	vec2 uv = (UV - 0.5) * 2.0 * uv_scale;
+	
+	float value = 0.0;
+	
+	// Octaves
+	float a = 0.6;
+	float f = 1.0;
+	for(int i = 0; i < octaves; i++) {
+		float v1 = voronoi(uv * f + 5.0);
+		float v2 = 0.0;
+		
+		// Sharp edges
+		v1 = 1.0 - smoothstep(0.0, edge_sharpness, v1);
+		// noise as intensity map
+		v2 = a * (noise1(v1 * 5.5 + 0.1));
+		
+		value += v2;
+		
+		f *= octave_scale;
+		a *= octave_dropoff;
+	}
+	
+	// Use value as bump map
+	float dZ = 1.0 / bump_strength;
+	vec3 nmap = normalize(vec3(dFdx(value), dFdy(value), dZ));
+	NORMAL_MAP = nmap / 2.0 + 1.0;
+	
+	
+	ALBEDO = value * base_color;
+	ROUGHNESS = value * roughness_scale;
+	METALLIC = metallic;
+}

assets/materials/shaders/fractal_steel.gdshader.uid

@@ -0,0 +1 @@
+uid://c0gt2lo07w7w