private static string GetShaderPassFromTemplate(string template, UnlitMasterNode masterNode, Pass pass, GenerationMode mode)
        {
            // ----------------------------------------------------- //
            //                         SETUP                         //
            // ----------------------------------------------------- //

            // -------------------------------------
            // String builders

            var shaderProperties = new PropertyCollector();
            var functionBuilder = new ShaderStringBuilder(1);
            var functionRegistry = new FunctionRegistry(functionBuilder);

            var defines = new ShaderStringBuilder(1);
            var graph = new ShaderStringBuilder(0);

            var surfaceDescriptionInputStruct = new ShaderStringBuilder(1);
            var surfaceDescriptionFunction = new ShaderStringBuilder(1);
            var surfaceDescriptionStruct = new ShaderStringBuilder(1); 

            var pixelShader = new ShaderStringBuilder(2);
            var pixelShaderSurfaceInputs = new ShaderStringBuilder(2);
            var pixelShaderSurfaceRemap = new ShaderStringBuilder(2);

            // -------------------------------------
            // Get Slot and Node lists per stage

            var pixelSlots = pass.PixelShaderSlots.Select(masterNode.FindSlot<MaterialSlot>).ToList();
            var pixelNodes = ListPool<INode>.Get();
            NodeUtils.DepthFirstCollectNodesFromNode(pixelNodes, masterNode, NodeUtils.IncludeSelf.Include, pass.PixelShaderSlots);

            // -------------------------------------
            // Get Requirements

            var pixelRequirements = ShaderGraphRequirements.FromNodes(pixelNodes);

            // ----------------------------------------------------- //
            //                START SHADER GENERATION                //
            // ----------------------------------------------------- //

            // -------------------------------------
            // Calculate material options

            var tagsBuilder = new ShaderStringBuilder(1);
            var blendingBuilder = new ShaderStringBuilder(1);
            var cullingBuilder = new ShaderStringBuilder(1);
            var zTestBuilder = new ShaderStringBuilder(1);
            var zWriteBuilder = new ShaderStringBuilder(1);

            var materialOptions = new SurfaceMaterialOptions();
            materialOptions.GetTags(tagsBuilder);
            materialOptions.GetBlend(blendingBuilder);
            materialOptions.GetCull(cullingBuilder);
            materialOptions.GetDepthTest(zTestBuilder);
            materialOptions.GetDepthWrite(zWriteBuilder);

            // -------------------------------------
            // Generate defines

            defines.AppendLine("#define SHADERPASS {0}", pass.ShaderPassName);
            foreach (var channel in pixelRequirements.requiresMeshUVs.Distinct())
            {
                defines.AppendLine("#define ATTRIBUTES_NEED_TEXCOORD{0}", (int)channel);
                defines.AppendLine("#define VARYINGS_NEED_TEXCOORD{0}", (int)channel);
            }

            if (masterNode.IsSlotConnected(PBRMasterNode.AlphaThresholdSlotId))
                defines.AppendLine("#define _ALPHATEST_ON");

            // ----------------------------------------------------- //
            //               START SURFACE DESCRIPTION               //
            // ----------------------------------------------------- //

            // -------------------------------------
            // Generate Input structure for Surface Description function
            // Surface Description Input requirements are needed to exclude intermediate translation spaces

            surfaceDescriptionInputStruct.AppendLine("struct SurfaceDescriptionInputs", false);
            using(surfaceDescriptionInputStruct.BlockSemicolonScope())
            {
                ShaderGenerator.GenerateSpaceTranslationSurfaceInputs(pixelRequirements.requiresNormal, InterpolatorType.Normal, surfaceDescriptionInputStruct);
                ShaderGenerator.GenerateSpaceTranslationSurfaceInputs(pixelRequirements.requiresTangent, InterpolatorType.Tangent, surfaceDescriptionInputStruct);
                ShaderGenerator.GenerateSpaceTranslationSurfaceInputs(pixelRequirements.requiresBitangent, InterpolatorType.BiTangent, surfaceDescriptionInputStruct);
                ShaderGenerator.GenerateSpaceTranslationSurfaceInputs(pixelRequirements.requiresViewDir, InterpolatorType.ViewDirection, surfaceDescriptionInputStruct);
                ShaderGenerator.GenerateSpaceTranslationSurfaceInputs(pixelRequirements.requiresPosition, InterpolatorType.Position, surfaceDescriptionInputStruct);

                if (pixelRequirements.requiresVertexColor)
                    surfaceDescriptionInputStruct.AppendLine("float4 {0};", ShaderGeneratorNames.VertexColor);

                if (pixelRequirements.requiresScreenPosition)
                    surfaceDescriptionInputStruct.AppendLine("float4 {0};", ShaderGeneratorNames.ScreenPosition);

                foreach (var channel in pixelRequirements.requiresMeshUVs.Distinct())
            {
                    surfaceDescriptionInputStruct.AppendLine("half4 {0};", channel.GetUVName());
                }
            }

            // -------------------------------------
            // Generate Output structure for Surface Description function

            GraphUtil.GenerateSurfaceDescriptionStruct(surfaceDescriptionStruct, pixelSlots, true);
            
            // -------------------------------------
            // Generate Surface Description function

            GraphUtil.GenerateSurfaceDescriptionFunction(
                pixelNodes,
                masterNode,
                masterNode.owner as AbstractMaterialGraph,
                surfaceDescriptionFunction,
                functionRegistry,
                shaderProperties,
                pixelRequirements,
                mode,
                "PopulateSurfaceData",
                "SurfaceDescription",
                null,
                pixelSlots);

            // ----------------------------------------------------- //
            //           GENERATE VERTEX > PIXEL PIPELINE            //
            // ----------------------------------------------------- //

            // -------------------------------------
            // TODO - Why is this not a full generation?
            // Generate standard transformations

            foreach (var channel in pixelRequirements.requiresMeshUVs.Distinct())
                pixelShaderSurfaceInputs.AppendLine("surfaceInput.{0} = {1};", channel.GetUVName(), string.Format("half4(input.texCoord{0}, 0, 0)", (int)channel));

            // -------------------------------------
            // Generate pixel shader surface remap

            foreach (var slot in pixelSlots)
            {
                pixelShaderSurfaceRemap.AppendLine("{0} = surf.{0};", slot.shaderOutputName);
            }

            // ----------------------------------------------------- //
            //                      FINALIZE                         //
            // ----------------------------------------------------- //

            // -------------------------------------
            // Combine Graph sections
            
            graph.AppendLine(shaderProperties.GetPropertiesDeclaration(1));

            graph.AppendLine(functionBuilder.ToString());

            graph.AppendLine(surfaceDescriptionInputStruct.ToString());
            graph.AppendLine(surfaceDescriptionStruct.ToString());
            graph.AppendLine(surfaceDescriptionFunction.ToString());

            // -------------------------------------
            // Generate final subshader

            var resultPass = template.Replace("${Tags}", tagsBuilder.ToString());
            resultPass = resultPass.Replace("${Blending}", blendingBuilder.ToString());
            resultPass = resultPass.Replace("${Culling}", cullingBuilder.ToString());
            resultPass = resultPass.Replace("${ZTest}", zTestBuilder.ToString());
            resultPass = resultPass.Replace("${ZWrite}", zWriteBuilder.ToString());
            resultPass = resultPass.Replace("${Defines}", defines.ToString());
            resultPass = resultPass.Replace("${LOD}", "" + materialOptions.lod);

            resultPass = resultPass.Replace("${LightMode}", pass.Name);
            resultPass = resultPass.Replace("${ShaderPassInclude}", pass.ShaderPassInclude);
            
            resultPass = resultPass.Replace("${Graph}", graph.ToString());

            resultPass = resultPass.Replace("${PixelShader}", pixelShader.ToString());
            resultPass = resultPass.Replace("${PixelShaderSurfaceInputs}", pixelShaderSurfaceInputs.ToString());
            resultPass = resultPass.Replace("${PixelShaderSurfaceRemap}", pixelShaderSurfaceRemap.ToString());
            
            return resultPass;
        }
        private static string GetShaderPassFromTemplate(
            string template,
            UnlitMasterNode masterNode,
            Pass pass,
            GenerationMode mode,
            SurfaceMaterialOptions materialOptions)
        {
            var builder = new ShaderStringBuilder();

            builder.IncreaseIndent();
            builder.IncreaseIndent();
            var vertexInputs               = new ShaderGenerator();
            var surfaceVertexShader        = new ShaderGenerator();
            var surfaceDescriptionFunction = new ShaderGenerator();
            var surfaceDescriptionStruct   = new ShaderGenerator();
            var functionRegistry           = new FunctionRegistry(builder);
            var surfaceInputs              = new ShaderGenerator();

            var shaderProperties = new PropertyCollector();

            surfaceInputs.AddShaderChunk("struct SurfaceInputs{", false);
            surfaceInputs.Indent();

            var activeNodeList = ListPool <INode> .Get();

            NodeUtils.DepthFirstCollectNodesFromNode(activeNodeList, masterNode, NodeUtils.IncludeSelf.Include, pass.PixelShaderSlots);

            var requirements = ShaderGraphRequirements.FromNodes(activeNodeList);

            GraphUtil.GenerateApplicationVertexInputs(requirements, vertexInputs);
            ShaderGenerator.GenerateSpaceTranslationSurfaceInputs(requirements.requiresNormal, InterpolatorType.Normal, surfaceInputs);
            ShaderGenerator.GenerateSpaceTranslationSurfaceInputs(requirements.requiresTangent, InterpolatorType.Tangent, surfaceInputs);
            ShaderGenerator.GenerateSpaceTranslationSurfaceInputs(requirements.requiresBitangent, InterpolatorType.BiTangent, surfaceInputs);
            ShaderGenerator.GenerateSpaceTranslationSurfaceInputs(requirements.requiresViewDir, InterpolatorType.ViewDirection, surfaceInputs);
            ShaderGenerator.GenerateSpaceTranslationSurfaceInputs(requirements.requiresPosition, InterpolatorType.Position, surfaceInputs);

            if (requirements.requiresVertexColor)
            {
                surfaceInputs.AddShaderChunk(string.Format("float4 {0};", ShaderGeneratorNames.VertexColor), false);
            }

            if (requirements.requiresScreenPosition)
            {
                surfaceInputs.AddShaderChunk(string.Format("float4 {0};", ShaderGeneratorNames.ScreenPosition), false);
            }

            foreach (var channel in requirements.requiresMeshUVs.Distinct())
            {
                surfaceInputs.AddShaderChunk(string.Format("half4 {0};", channel.GetUVName()), false);
            }

            surfaceInputs.Deindent();
            surfaceInputs.AddShaderChunk("};", false);

            surfaceVertexShader.AddShaderChunk("GraphVertexInput PopulateVertexData(GraphVertexInput v){", false);
            surfaceVertexShader.Indent();
            surfaceVertexShader.AddShaderChunk("return v;", false);
            surfaceVertexShader.Deindent();
            surfaceVertexShader.AddShaderChunk("}", false);

            var slots = new List <MaterialSlot>();

            foreach (var id in pass.PixelShaderSlots)
            {
                var slot = masterNode.FindSlot <MaterialSlot>(id);
                if (slot != null)
                {
                    slots.Add(slot);
                }
            }
            GraphUtil.GenerateSurfaceDescriptionStruct(surfaceDescriptionStruct, slots, true);

            var usedSlots = new List <MaterialSlot>();

            foreach (var id in pass.PixelShaderSlots)
            {
                usedSlots.Add(masterNode.FindSlot <MaterialSlot>(id));
            }

            GraphUtil.GenerateSurfaceDescription(
                activeNodeList,
                masterNode,
                masterNode.owner as AbstractMaterialGraph,
                surfaceDescriptionFunction,
                functionRegistry,
                shaderProperties,
                requirements,
                mode,
                "PopulateSurfaceData",
                "SurfaceDescription",
                null,
                usedSlots);

            var graph = new ShaderGenerator();

            graph.AddShaderChunk(shaderProperties.GetPropertiesDeclaration(2), false);
            graph.AddShaderChunk(surfaceInputs.GetShaderString(2), false);
            graph.AddShaderChunk(builder.ToString(), false);
            graph.AddShaderChunk(vertexInputs.GetShaderString(2), false);
            graph.AddShaderChunk(surfaceDescriptionStruct.GetShaderString(2), false);
            graph.AddShaderChunk(surfaceVertexShader.GetShaderString(2), false);
            graph.AddShaderChunk(surfaceDescriptionFunction.GetShaderString(2), false);

            var blendingVisitor = new ShaderGenerator();
            var cullingVisitor  = new ShaderGenerator();
            var zTestVisitor    = new ShaderGenerator();
            var zWriteVisitor   = new ShaderGenerator();

            materialOptions.GetBlend(blendingVisitor);
            materialOptions.GetCull(cullingVisitor);
            materialOptions.GetDepthTest(zTestVisitor);
            materialOptions.GetDepthWrite(zWriteVisitor);

            var interpolators      = new ShaderGenerator();
            var localVertexShader  = new ShaderGenerator();
            var localPixelShader   = new ShaderGenerator();
            var localSurfaceInputs = new ShaderGenerator();
            var surfaceOutputRemap = new ShaderGenerator();

            var reqs = ShaderGraphRequirements.none;

            ShaderGenerator.GenerateStandardTransforms(
                3,
                10,
                interpolators,
                localVertexShader,
                localPixelShader,
                localSurfaceInputs,
                requirements,
                reqs,
                CoordinateSpace.World);

            ShaderGenerator defines = new ShaderGenerator();

            if (masterNode.IsSlotConnected(UnlitMasterNode.AlphaThresholdSlotId))
            {
                defines.AddShaderChunk("#define _AlphaClip 1", true);
            }

            var templateLocation = ShaderGenerator.GetTemplatePath(template);

            foreach (var slot in usedSlots)
            {
                surfaceOutputRemap.AddShaderChunk(slot.shaderOutputName
                                                  + " = surf."
                                                  + slot.shaderOutputName + ";", true);
            }

            if (!File.Exists(templateLocation))
            {
                return(string.Empty);
            }

            var subShaderTemplate = File.ReadAllText(templateLocation);
            var resultPass        = subShaderTemplate.Replace("${Defines}", defines.GetShaderString(3));

            resultPass = resultPass.Replace("${Graph}", graph.GetShaderString(3));
            resultPass = resultPass.Replace("${Interpolators}", interpolators.GetShaderString(3));
            resultPass = resultPass.Replace("${VertexShader}", localVertexShader.GetShaderString(3));
            resultPass = resultPass.Replace("${LocalPixelShader}", localPixelShader.GetShaderString(3));
            resultPass = resultPass.Replace("${SurfaceInputs}", localSurfaceInputs.GetShaderString(3));
            resultPass = resultPass.Replace("${SurfaceOutputRemap}", surfaceOutputRemap.GetShaderString(3));

            resultPass = resultPass.Replace("${Tags}", string.Empty);
            resultPass = resultPass.Replace("${Blending}", blendingVisitor.GetShaderString(2));
            resultPass = resultPass.Replace("${Culling}", cullingVisitor.GetShaderString(2));
            resultPass = resultPass.Replace("${ZTest}", zTestVisitor.GetShaderString(2));
            resultPass = resultPass.Replace("${ZWrite}", zWriteVisitor.GetShaderString(2));
            return(resultPass);
        }