invert TBN, glTF texture transform (playcanvas#3363)

slimbuck · web-flow · commit 225bdc745906 · 2021-07-23T17:05:05.000+01:00
diff --git a/src/graphics/program-lib/chunks/TBNderivative.frag b/src/graphics/program-lib/chunks/TBNderivative.frag
@@ -17,5 +17,5 @@ void getTBN() {
     // construct a scale-invariant frame
     float denom = max( dot(T,T), dot(B,B) );
     float invmax = (denom == 0.0) ? 0.0 : 1.0 / sqrt( denom );
-    dTBN = mat3( T * invmax, B * invmax, dVertexNormalW );
+    dTBN = mat3( T * invmax, -B * invmax, dVertexNormalW );
 }
diff --git a/src/resources/parser/glb-parser.js b/src/resources/parser/glb-parser.js
@@ -975,7 +975,7 @@ const createMaterial = function (gltfMaterial, textures, disableFlipV) {
         // texture coordinate V at load time.
         for (map = 0; map < maps.length; ++map) {
             material[maps[map] + 'MapTiling'] = new Vec2(scale[0], scale[1]);
-            material[maps[map] + 'MapOffset'] = new Vec2(offset[0], disableFlipV ? offset[1] : 1.0 - scale[1] - offset[1]);
+            material[maps[map] + 'MapOffset'] = new Vec2(offset[0], disableFlipV ? 1.0 - scale[1] - offset[1] : offset[1]);
         }
     };
 

Original file line number	Diff line number	Diff line change
`@@ -17,5 +17,5 @@ void getTBN() {`
`17`	`17`	`// construct a scale-invariant frame`
`18`	`18`	`float denom = max( dot(T,T), dot(B,B) );`
`19`	`19`	`float invmax = (denom == 0.0) ? 0.0 : 1.0 / sqrt( denom );`
`20`		`- dTBN = mat3( T * invmax, B * invmax, dVertexNormalW );`
	`20`	`+ dTBN = mat3( T * invmax, -B * invmax, dVertexNormalW );`
`21`	`21`	`}`
Original file line number	Diff line number	Diff line change
`@@ -975,7 +975,7 @@ const createMaterial = function (gltfMaterial, textures, disableFlipV) {`
`975`	`975`	`// texture coordinate V at load time.`
`976`	`976`	`for (map = 0; map < maps.length; ++map) {`
`977`	`977`	`material[maps[map] + 'MapTiling'] = new Vec2(scale[0], scale[1]);`
`978`		`- material[maps[map] + 'MapOffset'] = new Vec2(offset[0], disableFlipV ? offset[1] : 1.0 - scale[1] - offset[1]);`
	`978`	`+ material[maps[map] + 'MapOffset'] = new Vec2(offset[0], disableFlipV ? 1.0 - scale[1] - offset[1] : offset[1]);`
`979`	`979`	`}`
`980`	`980`	`};`
`981`	`981`