Merge pull request #8 from MathemanFlo/blend_normals

Add Blend Normal Maps node

Sources/arm/shader/MaterialParser.hx

@@ -954,6 +954,35 @@ class MaterialParser {
 
 			return '(0.5 * ${store}_texn + 0.5)';
 		}
+		else if (node.type == "BLEND_NORMAL_MAPS") {
+			var nm1 = parse_vector_input(node.inputs[0]);
+			var nm2 = parse_vector_input(node.inputs[1]);
+			var but = node.buttons[0];
+			var blend: String = but.data[but.default_value].toUpperCase(); //blend type
+			blend = blend.replace(" ", "_");
+			
+			var store = store_var_name(node);
+			
+			/* The blending algorithms are based on the paper 'Blending in Detail' by Colin Barré-Brisebois and Stephen Hill 2012
+			   https://blog.selfshadow.com/publications/blending-in-detail/
+			*/
+			
+			if( blend == "PARTIAL_DERIVATIVE") { //partial derivate blending
+				curshader.write('vec3 ${store}_n1 = $nm1 * 2.0 - 1.0;');
+				curshader.write('vec3 ${store}_n2 = $nm2 * 2.0 - 1.0;');
+				return '0.5*normalize(vec3(${store}_n1.xy*${store}_n2.z + ${store}_n2.xy*${store}_n1.z, ${store}_n1.z*${store}_n2.z))+0.5;';
+			}
+			else if (blend == "WHITEOUT") { //whiteout blending
+				curshader.write('vec3 ${store}_n1 = $nm1 * 2.0 - 1.0;');
+				curshader.write('vec3 ${store}_n2 = $nm2 * 2.0 - 1.0;');
+				return '0.5*normalize(vec3(${store}_n1.xy + ${store}_n2.xy, ${store}_n1.z*${store}_n2.z))+0.5;';
+			}
+			else if (blend == "REORIENTED") { //reoriented normal mapping
+				curshader.write('vec3 ${store}_n1 = $nm1 * 2.0 - vec3(1.0,1.0,0.0);');
+				curshader.write('vec3 ${store}_n2 = $nm2 * vec3(-2.0,-2.0,2.0) - vec3(-1.0,-1.0,1.0);');
+				return '0.5*normalize(${store}_n1*dot(${store}_n1, ${store}_n2) - ${store}_n2*${store}_n1.z)+0.5';
+			}
+		}
 		else if (node.type == "VECT_TRANSFORM") {
 		// 	#type = node.vector_type
 		// 	#conv_from = node.convert_from

Sources/arm/shader/NodesMaterial.hx

@@ -2057,6 +2057,51 @@ class NodesMaterial {
 				],
 				buttons: []
 			},
+			{
+				id: 0,
+				name: _tr("Blend Normal Maps"),
+				type: "BLEND_NORMAL_MAPS",
+				x: 0,
+				y: 0,
+				color: 0xff522c99,
+				inputs: [
+					{
+						id: 0,
+						node_id: 0,
+						name: _tr("1. Normal Map"),
+						type: "VECTOR",
+						color: -10238109,
+						default_value: f32([0.5, 0.5, 1.0])
+					},
+					{
+						id: 0,
+						node_id: 0,
+						name: _tr("2. Normal Map"),
+						type: "VECTOR",
+						color: -10238109,
+						default_value: f32([0.5, 0.5, 1.0])
+					}
+				],
+				outputs: [
+					{
+						id: 0,
+						node_id: 0,
+						name: _tr("Normal Map"),
+						type: "VECTOR",
+						color: -10238109,
+						default_value: f32([0.5, 0.5, 1.0])
+					}
+				],
+				buttons: [
+					{
+						name: _tr("blend_type"),
+						type: "ENUM",
+						data: [_tr("Partial Derivative"), _tr("Whiteout"), _tr("Reoriented")],
+						default_value: 0,
+						output: 0
+					}
+				]
+			},
 			{
 				id: 0,
 				name: _tr("Vector Curves"),