restore blend weight function

src/shaders/main.glsl

@@ -301,6 +301,13 @@ vec2 project_uv_from_normal(vec3 normal) {
 	return vec2(dot(v_vertex, p_tangent), dot(v_vertex, normalize(cross(p_tangent, p_normal)))) * scale;
 }
 
+float blend_weights(float weight, float detail) {
+	weight = smoothstep(0.0, 1.0, weight);
+	weight = sqrt(weight * 0.5);
+	float result = max(0.1 * weight, fma(10.0, (weight + detail), 1.0f - (detail + 10.0)));
+	return weight;
+}
+
 void fragment() {
 	// Recover UVs
 	vec2 uv = UV + v_uv_offset;
@@ -402,19 +409,16 @@ void fragment() {
 		get_material(project_uv_from_normal(index_normal[2]), base_derivatives, control[2], indexUV[2], w_normal, mat[2]);
 
 		// rebuild weights for detail and noise blending
-		float noise3 = (0.333 - texture(noise_texture, uv * noise3_scale).r) * blend_sharpness;
-		#define PARABOLA(x) (4.0*x*(1.0-x))
-		weight.x += PARABOLA(weight.x) * noise3;
-		weight.y += PARABOLA(weight.y) * noise3;
-		#undef PARABOLA
-		weight = smoothstep(vec2(0.0), vec2(1.0), weight);
-		invert = 1.0 - weight;
+		float noise3 = texture(noise_texture, uv * noise3_scale).r * blend_sharpness;
+		#define PARABOLA(x) (4.0 * x * (1.0 - x))
+		weights = smoothstep(0, 1, weights);
 		weights = vec4(
-			(mat[0].alb_ht.a + 1e-6) * invert.x * weight.y,
-			(mat[1].alb_ht.a + 1e-6) * weight.x * weight.y,
-			(mat[2].alb_ht.a + 1e-6) * weight.x * invert.y,
-			(mat[3].alb_ht.a + 1e-6) * invert.x * invert.y
+			blend_weights(weights.x + PARABOLA(weights.x) * noise3, mat[0].alb_ht.a),
+			blend_weights(weights.y + PARABOLA(weights.y) * noise3, mat[1].alb_ht.a),
+			blend_weights(weights.z + PARABOLA(weights.z) * noise3, mat[2].alb_ht.a),
+			blend_weights(weights.w + PARABOLA(weights.w) * noise3, mat[3].alb_ht.a)
 		);
+		#undef PARABOLA
 		// renormalize weights
 		weights *= 1.0 / (weights.x + weights.y + weights.z + weights.w);