TooledSteel.osl

//Tooled Steel by Ivan DeWolf
// Modified 4/27/21 by Saul Espinosa for Redshift3d
// Added ACES output, min/max and page meta data and Coating Microfacet GGX Closure Layer

vector nearPtLine(
    point testLoc,
    point lineStart,
    point lineEnd)
{
    float lineMag = distance(lineStart, lineEnd);
    float U = dot(testLoc-lineStart, lineEnd - lineStart) / (lineMag * lineMag);
    return lineStart + U * (lineEnd - lineStart);
}

shader tooldSteel
[[  string help = "Machine Tooled Material Shader",
    string label = "Machine Tooled Steel" ]]
(
    color metal_color = color(0.9,0.8,0.7)
		[[
			string page = "0 : Metal",
			string label = "Metal Color"
		]],
    float xalph = 1
		[[
			string page = "0 : Metal",
			string label = "Anisotropy Roughness x",
			float min =  0,
			float max = 1
		]],
    float yalph = .1
		[[
			string page = "0 : Metal",
			string label = "Anisotropy Roughness y",
			float min =  0,
			float max = 1
		]],
	float IOR = 15
		[[
			string page = "0 : Metal",
			float min =  1,
			float max = 25
		]],
    float cellmult = 10
		[[
			string page = "0 : Metal",
			string label = "Scale",
			float min =  0,
			float max = 100
		]],
	color coat_color = color(1.0)
		[[string label = "Coat Color",
		string page = "1 : Coat",
		]],
	float coat_weight = 0.0
		[[string label = "Coat Weight" ,
		string page = "1 : Coat",
	float min = 0, float max = 1
		]],
	float coat_roughness = 0.0
		[[string label = "Coat Roughness" ,
		string page = "1 : Coat",
	float min = 0, float max = 1
		]],
	float coat_IOR = 1.52
		[[string label = "Coat IOR" ,
		string page = "1 : Coat",
	float min = 0, float max = 25
		]],
	int   aces = 0
		[[
		string page = "2 : Extra",
		string widget = "checkBox",
		int connectable = 0,
		string label = "ACES"
		]],

		
    output closure color outColor = 0.0)
{
	// ACES sRGB Transform
	matrix aces_tm = matrix(
		0.6131, 0.0701, 0.0206, 0,
		0.3395, 0.9164, 0.1096, 0,
		0.0474, 0.0135, 0.8698, 0,
		0, 0, 0, 1);
		
	color Out = metal_color;
	float r = Out[0], g = Out[1], b = Out[2];
	
	if (aces == 0)
	color attenColor = Out;
	else
	{
	attenColor = transform(aces_tm, vector(r,g,b));
	}	
	
	vector Normal = N;
	point Ploc = P;

    vector centerLoc = round(Ploc * cellmult)/cellmult;
    vector spinCenter = nearPtLine(Ploc, centerLoc+Normal, centerLoc -Normal);
    vector anisoDir = normalize(spinCenter-Ploc);
    outColor = attenColor * microfacet("ggx", Normal, anisoDir, xalph, yalph, IOR, 0) + (coat_color * coat_weight * microfacet("ggx",Normal,coat_roughness,coat_IOR,0));
}