Cycles: switch to squared roughness convention for all nodes.

This was already done for the Principled BSDF to be compatible with typical
baked roughness maps in PBR workflows.

4 files changed, 25 insertions, 20 deletions

diff --git a/intern/cycles/kernel/shaders/node_anisotropic_bsdf.osl b/intern/cycles/kernel/shaders/node_anisotropic_bsdf.osl
index bef6d7e8809..21e28ece65d 100644
--- a/intern/cycles/kernel/shaders/node_anisotropic_bsdf.osl
+++ b/intern/cycles/kernel/shaders/node_anisotropic_bsdf.osl
@@ -33,27 +33,28 @@ shader node_anisotropic_bsdf(
 		T = rotate(T, Rotation * M_2PI, point(0.0, 0.0, 0.0), Normal);
 
 	/* compute roughness */
-	float RoughnessU, RoughnessV;
+	float roughness = Roughness * Roughness;
+	float roughness_u, roughness_v;
 	float aniso = clamp(Anisotropy, -0.99, 0.99);
 
 	if (aniso < 0.0) {
-		RoughnessU = Roughness / (1.0 + aniso);
-		RoughnessV = Roughness * (1.0 + aniso);
+		roughness_u = roughness / (1.0 + aniso);
+		roughness_v = roughness * (1.0 + aniso);
 	}
 	else {
-		RoughnessU = Roughness * (1.0 - aniso);
-		RoughnessV = Roughness / (1.0 - aniso);
+		roughness_u = roughness * (1.0 - aniso);
+		roughness_v = roughness / (1.0 - aniso);
 	}
 
 	if (distribution == "sharp")
 		BSDF = Color * reflection(Normal);
 	else if (distribution == "beckmann")
-		BSDF = Color * microfacet_beckmann_aniso(Normal, T, RoughnessU, RoughnessV);
+		BSDF = Color * microfacet_beckmann_aniso(Normal, T, roughness_u, roughness_v);
 	else if (distribution == "GGX")
-		BSDF = Color * microfacet_ggx_aniso(Normal, T, RoughnessU, RoughnessV);
+		BSDF = Color * microfacet_ggx_aniso(Normal, T, roughness_u, roughness_v);
 	else if (distribution == "Multiscatter GGX")
-		BSDF = Color * microfacet_multi_ggx_aniso(Normal, T, RoughnessU, RoughnessV, Color);
+		BSDF = Color * microfacet_multi_ggx_aniso(Normal, T, roughness_u, roughness_v, Color);
 	else
-		BSDF = Color * ashikhmin_shirley(Normal, T, RoughnessU, RoughnessV);
+		BSDF = Color * ashikhmin_shirley(Normal, T, roughness_u, roughness_v);
 }
 
diff --git a/intern/cycles/kernel/shaders/node_glass_bsdf.osl b/intern/cycles/kernel/shaders/node_glass_bsdf.osl
index a9723a8300a..2e713861c58 100644
--- a/intern/cycles/kernel/shaders/node_glass_bsdf.osl
+++ b/intern/cycles/kernel/shaders/node_glass_bsdf.osl
@@ -29,16 +29,17 @@ shader node_glass_bsdf(
 	float eta = backfacing() ? 1.0 / f : f;
 	float cosi = dot(I, Normal);
 	float Fr = fresnel_dielectric_cos(cosi, eta);
+	float roughness = Roughness * Roughness;
 
 	if (distribution == "sharp")
 		BSDF = Color * (Fr * reflection(Normal) + (1.0 - Fr) * refraction(Normal, eta));
 	else if (distribution == "beckmann")
-		BSDF = Color * (Fr * microfacet_beckmann(Normal, Roughness) +
-		                (1.0 - Fr) * microfacet_beckmann_refraction(Normal, Roughness, eta));
+		BSDF = Color * (Fr * microfacet_beckmann(Normal, roughness) +
+		                (1.0 - Fr) * microfacet_beckmann_refraction(Normal, roughness, eta));
 	else if (distribution == "Multiscatter GGX")
-		BSDF = Color * microfacet_multi_ggx_glass(Normal, Roughness, eta, Color);
+		BSDF = Color * microfacet_multi_ggx_glass(Normal, roughness, eta, Color);
 	else if (distribution == "GGX")
-		BSDF = Color * (Fr * microfacet_ggx(Normal, Roughness) +
-		                (1.0 - Fr) * microfacet_ggx_refraction(Normal, Roughness, eta));
+		BSDF = Color * (Fr * microfacet_ggx(Normal, roughness) +
+		                (1.0 - Fr) * microfacet_ggx_refraction(Normal, roughness, eta));
 }
 
diff --git a/intern/cycles/kernel/shaders/node_glossy_bsdf.osl b/intern/cycles/kernel/shaders/node_glossy_bsdf.osl
index f4ea7e7dc6a..7415211b56d 100644
--- a/intern/cycles/kernel/shaders/node_glossy_bsdf.osl
+++ b/intern/cycles/kernel/shaders/node_glossy_bsdf.osl
@@ -24,16 +24,18 @@ shader node_glossy_bsdf(
 	normal Normal = N,
 	output closure color BSDF = 0)
 {
+	float roughness = Roughness * Roughness;
+
 	if (distribution == "sharp")
 		BSDF = Color * reflection(Normal);
 	else if (distribution == "beckmann")
-		BSDF = Color * microfacet_beckmann(Normal, Roughness);
+		BSDF = Color * microfacet_beckmann(Normal, roughness);
 	else if (distribution == "GGX")
-		BSDF = Color * microfacet_ggx(Normal, Roughness);
+		BSDF = Color * microfacet_ggx(Normal, roughness);
 	else if (distribution == "Multiscatter GGX")
-		BSDF = Color * microfacet_multi_ggx(Normal, Roughness, Color);
+		BSDF = Color * microfacet_multi_ggx(Normal, roughness, Color);
 	else
-		BSDF = Color * ashikhmin_shirley(Normal, vector(0, 0, 0), Roughness, Roughness);
+		BSDF = Color * ashikhmin_shirley(Normal, vector(0, 0, 0), roughness, roughness);
 
 }
 
diff --git a/intern/cycles/kernel/shaders/node_refraction_bsdf.osl b/intern/cycles/kernel/shaders/node_refraction_bsdf.osl
index 828becf1818..eaab7282243 100644
--- a/intern/cycles/kernel/shaders/node_refraction_bsdf.osl
+++ b/intern/cycles/kernel/shaders/node_refraction_bsdf.osl
@@ -26,12 +26,13 @@ shader node_refraction_bsdf(
 {
 	float f = max(IOR, 1e-5);
 	float eta = backfacing() ? 1.0 / f : f;
+	float roughness = Roughness * Roughness;
 
 	if (distribution == "sharp")
 		BSDF = Color * refraction(Normal, eta);
 	else if (distribution == "beckmann")
-		BSDF = Color * microfacet_beckmann_refraction(Normal, Roughness, eta);
+		BSDF = Color * microfacet_beckmann_refraction(Normal, roughness, eta);
 	else if (distribution == "GGX")
-		BSDF = Color * microfacet_ggx_refraction(Normal, Roughness, eta);
+		BSDF = Color * microfacet_ggx_refraction(Normal, roughness, eta);
 }