Make clearcoat bump work whatever the tangent availability

src/Materials/Node/Blocks/PBR/clearCoatBlock.ts

@@ -43,6 +43,7 @@ export class ClearCoatBlock extends NodeMaterialBlock {
         this.registerInput("tintAtDistance", NodeMaterialBlockConnectionPointTypes.Float, true, NodeMaterialBlockTargets.Fragment);
         this.registerInput("tintThickness", NodeMaterialBlockConnectionPointTypes.Float, true, NodeMaterialBlockTargets.Fragment);
         this.registerInput("tintTexture", NodeMaterialBlockConnectionPointTypes.Color4, true, NodeMaterialBlockTargets.Fragment);
+        this.registerInput("worldTangent", NodeMaterialBlockConnectionPointTypes.Vector4, true);
 
         this.registerOutput("clearcoat", NodeMaterialBlockConnectionPointTypes.Object, NodeMaterialBlockTargets.Fragment,
             new NodeMaterialConnectionPointCustomObject("clearcoat", this, NodeMaterialConnectionPointDirection.Output, ClearCoatBlock, "ClearCoatBlock"));
@@ -139,6 +140,13 @@ export class ClearCoatBlock extends NodeMaterialBlock {
     }
 
     /**
+     * Gets the world tangent input component
+     */
+    public get worldTangent(): NodeMaterialConnectionPoint {
+        return this._inputs[10];
+    }
+
+    /**
      * Gets the clear coat object output component
      */
     public get clearcoat(): NodeMaterialConnectionPoint {
@@ -188,15 +196,44 @@ export class ClearCoatBlock extends NodeMaterialBlock {
         }
     }
 
+    private _generateTBNSpace(state: NodeMaterialBuildState, worldPositionVarName: string, worldNormalVarName: string) {
+        let code = "";
+
+        let comments = `//${this.name}`;
+        let worldTangent = this.worldTangent;
+
+        state._emitExtension("derivatives", "#extension GL_OES_standard_derivatives : enable");
+
+        let tangentReplaceString = { search: /defined\(TANGENT\)/g, replace: worldTangent.isConnected ? "defined(TANGENT)" : "defined(IGNORE)" };
+
+        if (worldTangent.isConnected) {
+            code += `vec3 tbnNormal = normalize(${worldNormalVarName}.xyz);\r\n`;
+            code += `vec3 tbnTangent = normalize(${worldTangent.associatedVariableName}.xyz);\r\n`;
+            code += `vec3 tbnBitangent = cross(tbnNormal, tbnTangent);\r\n`;
+            code += `mat3 vTBN = mat3(tbnTangent, tbnBitangent, tbnNormal);\r\n`;
+        }
+
+        state._emitFunctionFromInclude("bumpFragmentMainFunctions", comments, {
+            replaceStrings: [
+                tangentReplaceString,
+            ]
+        });
+
+        return code;
+    }
+
     /**
      * Gets the main code of the block (fragment side)
      * @param state current state of the node material building
      * @param ccBlock instance of a ClearCoatBlock or null if the code must be generated without an active clear coat module
      * @param reflectionBlock instance of a ReflectionBlock null if the code must be generated without an active reflection module
      * @param worldPosVarName name of the variable holding the world position
+     * @param generateTBNSpace if true, the code needed to create the TBN coordinate space is generated
+     * @param vTBNAvailable indicate that the vTBN variable is already existing because it has already been generated by another block (PerturbNormal or Anisotropy)
+     * @param worldNormalVarName name of the variable holding the world normal
      * @returns the shader code
      */
-    public static GetCode(state: NodeMaterialBuildState, ccBlock: Nullable<ClearCoatBlock>, reflectionBlock: Nullable<ReflectionBlock>, worldPosVarName: string): string {
+    public static GetCode(state: NodeMaterialBuildState, ccBlock: Nullable<ClearCoatBlock>, reflectionBlock: Nullable<ReflectionBlock>, worldPosVarName: string, generateTBNSpace: boolean, vTBNAvailable: boolean, worldNormalVarName: string): string {
         let code = "";
 
         const intensity = ccBlock?.intensity.isConnected ? ccBlock.intensity.associatedVariableName : "1.";
@@ -215,7 +252,12 @@ export class ClearCoatBlock extends NodeMaterialBlock {
             state._emitUniformFromString("vClearCoatTangentSpaceParams", "vec2");
         }
 
-        code = `clearcoatOutParams clearcoatOut;
+        if (generateTBNSpace && ccBlock) {
+            code += ccBlock._generateTBNSpace(state, worldPosVarName, worldNormalVarName);
+            vTBNAvailable = ccBlock.worldTangent.isConnected;
+        }
+
+        code += `clearcoatOutParams clearcoatOut;
 
         #ifdef CLEARCOAT
             vec2 vClearCoatParams = vec2(${intensity}, ${roughness});
@@ -242,7 +284,7 @@ export class ClearCoatBlock extends NodeMaterialBlock {
                 vec2(0., 1.),
                 ${bumpTexture},
                 ${uv},
-                #if defined(TANGENT) && defined(NORMAL)
+                #if defined(${vTBNAvailable ? "TANGENT" : "IGNORE"}) && defined(NORMAL)
                     vTBN,
                 #else
                     vClearCoatTangentSpaceParams,

src/Materials/Node/Blocks/PBR/pbrMetallicRoughnessBlock.ts

@@ -28,6 +28,7 @@ import { ReflectionBlock } from './reflectionBlock';
 import { ClearCoatBlock } from './clearCoatBlock';
 import { SubSurfaceBlock } from './subSurfaceBlock';
 import { RefractionBlock } from './refractionBlock';
+import { PerturbNormalBlock } from '../Fragment/perturbNormalBlock';
 
 const mapOutputToVariable: { [name: string] : [string, string] } = {
     "ambient":      ["finalAmbient", ""],
@@ -970,8 +971,16 @@ export class PBRMetallicRoughnessBlock extends NodeMaterialBlock {
 
         // _____________________________ Clear Coat ____________________________
         const clearcoatBlock = this.clearcoat.isConnected ? this.clearcoat.connectedPoint?.ownerBlock as ClearCoatBlock : null;
+        const generateTBNSpace = !this.perturbedNormal.isConnected && !this.anisotropy.isConnected;
+        const isTangentConnectedToPerturbNormal = this.perturbedNormal.isConnected && (this.perturbedNormal.connectedPoint?.ownerBlock as PerturbNormalBlock).worldTangent.isConnected;
+        const isTangentConnectedToAnisotropy = this.anisotropy.isConnected && (this.anisotropy.connectedPoint?.ownerBlock as AnisotropyBlock).worldTangent.isConnected;
+        let vTBNAvailable = isTangentConnectedToPerturbNormal || (!this.perturbedNormal.isConnected && isTangentConnectedToAnisotropy);
 
-        state.compilationString += ClearCoatBlock.GetCode(state, clearcoatBlock, reflectionBlock, worldPosVarName);
+        state.compilationString += ClearCoatBlock.GetCode(state, clearcoatBlock, reflectionBlock, worldPosVarName, generateTBNSpace, vTBNAvailable, this.worldNormal.associatedVariableName);
+
+        if (generateTBNSpace) {
+            vTBNAvailable = clearcoatBlock?.worldTangent.isConnected ?? false;
+        }
 
         state._emitFunctionFromInclude("pbrBlockClearcoat", comments, {
             replaceStrings: [
@@ -982,6 +991,7 @@ export class PBRMetallicRoughnessBlock extends NodeMaterialBlock {
                 { search: /REFLECTIONMAP_SKYBOX/g, replace: reflectionBlock?._defineSkyboxName ?? "REFLECTIONMAP_SKYBOX" },
                 { search: /LODINREFLECTIONALPHA/g, replace: reflectionBlock?._defineLODReflectionAlpha ?? "LODINREFLECTIONALPHA" },
                 { search: /LINEARSPECULARREFLECTION/g, replace: reflectionBlock?._defineLinearSpecularReflection ?? "LINEARSPECULARREFLECTION" },
+                { search: /defined\(TANGENT\)/g, replace: vTBNAvailable ? "defined(TANGENT)" : "defined(IGNORE)" },
             ]
         });