Updated builds

build/three.js

@@ -7789,7 +7789,11 @@
 						index2 = 0;
 
 				for (let i = 0, l = indices.length; i < l; i++) {
-					index = indices[i] * itemSize;
+					if (attribute.isInterleavedBufferAttribute) {
+						index = indices[i] * attribute.data.stride + attribute.offset;
+					} else {
+						index = indices[i] * itemSize;
+					}
 
 					for (let j = 0; j < itemSize; j++) {
 						array2[index2++] = array[index++];

build/three.module.js

@@ -10162,7 +10162,15 @@ class BufferGeometry extends EventDispatcher {
 
 			for ( let i = 0, l = indices.length; i < l; i ++ ) {
 
-				index = indices[ i ] * itemSize;
+				if ( attribute.isInterleavedBufferAttribute ) {
+
+					index = indices[ i ] * attribute.data.stride + attribute.offset;
+
+				} else {
+
+					index = indices[ i ] * itemSize;
+
+				}
 
 				for ( let j = 0; j < itemSize; j ++ ) {