From 8f8df34342012b70571bebdf24b2c3f27e4ba288 Mon Sep 17 00:00:00 2001
From: PrecisionRender <austin08dean@gmail.com>
Date: Wed, 24 Aug 2022 09:35:54 -0500
Subject: [PATCH] Add World Triplanar Texture node to shader editor

---
 Source/Editor/Surface/Archetypes/Textures.cs  | 20 +++++++++
 .../MaterialGenerator.Textures.cpp            | 45 +++++++++++++++++++
 2 files changed, 65 insertions(+)

diff --git a/Source/Editor/Surface/Archetypes/Textures.cs b/Source/Editor/Surface/Archetypes/Textures.cs
index a7180f78e..9043d6ea3 100644
--- a/Source/Editor/Surface/Archetypes/Textures.cs
+++ b/Source/Editor/Surface/Archetypes/Textures.cs
@@ -385,6 +385,26 @@ namespace FlaxEditor.Surface.Archetypes
                     NodeElementArchetype.Factory.Input(0, "World Position", true, typeof(Float3), 1),
                 }
             },
+            new NodeArchetype
+            {
+                TypeID = 16,
+                Title = "World Triplanar Texture",
+                Description = "Projects a texture using world-space coordinates instead of UVs.",
+                Flags = NodeFlags.MaterialGraph,
+                Size = new Float2(240, 80),
+                DefaultValues = new object[]
+                {
+                    1.0f,
+                    1.0f
+                },
+                Elements = new[]
+                {
+                    NodeElementArchetype.Factory.Input(0, "Texture", true, typeof(FlaxEngine.Object), 0),
+                    NodeElementArchetype.Factory.Input(1, "Scale", true, typeof(float), 1, 0),
+                    NodeElementArchetype.Factory.Input(2, "Blend", true, typeof(float), 2, 1),
+                    NodeElementArchetype.Factory.Output(0, "Color", typeof(Float3), 3)
+                }
+            },
         };
     }
 }
diff --git a/Source/Engine/Tools/MaterialGenerator/MaterialGenerator.Textures.cpp b/Source/Engine/Tools/MaterialGenerator/MaterialGenerator.Textures.cpp
index 5d19f46d2..3c08f8fea 100644
--- a/Source/Engine/Tools/MaterialGenerator/MaterialGenerator.Textures.cpp
+++ b/Source/Engine/Tools/MaterialGenerator/MaterialGenerator.Textures.cpp
@@ -444,6 +444,51 @@ void MaterialGenerator::ProcessGroupTextures(Box* box, Node* node, Value& value)
         value = box == gradientBox ? gradient : distance;
         break;
     }
+    // World Triplanar Texture
+    case 16:
+    {
+        // Get input boxes
+        auto textureBox = node->GetBox(0);
+        auto scaleBox = node->GetBox(1);
+        auto blendBox = node->GetBox(2);
+        
+        if (!textureBox->HasConnection())
+        {
+            // No texture to sample
+            value = Value::Zero;
+            break;
+        }
+
+        if (!CanUseSample(_treeType))
+        {
+            // Must sample texture in pixel shader
+            value = Value::Zero;
+            break;
+        }
+
+        const auto texture = eatBox(textureBox->GetParent<Node>(), textureBox->FirstConnection());
+        const auto scale = tryGetValue(scaleBox, node->Values[0]);
+        const auto blend = tryGetValue(blendBox, node->Values[1]);
+
+        auto result = writeLocal(Value::InitForZero(ValueType::Float4), node);
+
+        const String triplanarTexture = String::Format(TEXT(
+            "   float3 worldPos = input.WorldPosition.xyz * ({1} * 0.001f);\n"
+            "   float3 normal = input.TBN[2];\n"
+
+            "   {3} += {0}.Sample(SamplerLinearWrap, worldPos.yz) * pow(abs(dot(normal, float3(1,0,0))), {2});\n"
+            "   {3} += {0}.Sample(SamplerLinearWrap, worldPos.xz) * pow(abs(dot(normal, float3(0,1,0))), {2});\n"
+            "   {3} += {0}.Sample(SamplerLinearWrap, worldPos.xy) * pow(abs(dot(normal, float3(0,0,1))), {2});\n"
+        ),
+                texture.Value,  //  {0}
+                scale.Value,    //  {1}
+                blend.Value,    //  {2}
+                result.Value    //  {3}
+        );
+
+        _writer.Write(*triplanarTexture);
+        value = result;
+    }
     default:
         break;
     }