From b69281573f0053deda0d2196bf2d0500f4c213d3 Mon Sep 17 00:00:00 2001
From: Sean Lilley <lilleyse@gmail.com>
Date: Fri, 27 Mar 2020 09:41:37 -0400
Subject: [PATCH] Remove triangle winding order check

---
 lib/loadObj.js | 32 +-------------------------------
 1 file changed, 1 insertion(+), 31 deletions(-)

diff --git a/lib/loadObj.js b/lib/loadObj.js
index bb64340..16e53c8 100644
--- a/lib/loadObj.js
+++ b/lib/loadObj.js
@@ -256,18 +256,6 @@ function loadObj(objPath, options) {
         return Cartesian3.fromElements(px, py, pz, result);
     }
 
-    function getNormal(index, result) {
-        const nx = globalNormals.get(index * 3);
-        const ny = globalNormals.get(index * 3 + 1);
-        const nz = globalNormals.get(index * 3 + 2);
-        return Cartesian3.fromElements(nx, ny, nz, result);
-    }
-
-    const scratch1 = new Cartesian3();
-    const scratch2 = new Cartesian3();
-    const scratch3 = new Cartesian3();
-    const scratch4 = new Cartesian3();
-    const scratch5 = new Cartesian3();
     const scratchCenter = new Cartesian3();
     const scratchAxis1 = new Cartesian3();
     const scratchAxis2 = new Cartesian3();
@@ -276,23 +264,6 @@ function loadObj(objPath, options) {
     const scratchVertexIndices = [];
     const scratchPoints = [];
 
-    function checkWindingCorrect(positionIndex1, positionIndex2, positionIndex3, normalIndex) {
-        if (!defined(normalIndex)) {
-            // If no face normal, we have to assume the winding is correct.
-            return true;
-        }
-        const normal = getNormal(normalIndex, scratchNormal);
-        const A = getPosition(positionIndex1, scratch1);
-        const B = getPosition(positionIndex2, scratch2);
-        const C = getPosition(positionIndex3, scratch3);
-
-        const BA = Cartesian3.subtract(B, A, scratch4);
-        const CA = Cartesian3.subtract(C, A, scratch5);
-        const cross = Cartesian3.cross(BA, CA, scratch3);
-
-        return (Cartesian3.dot(normal, cross) >= 0);
-    }
-
     function addTriangle(index1, index2, index3, correctWinding) {
         if (correctWinding) {
             primitive.indices.push(index1);
@@ -314,11 +285,10 @@ function loadObj(objPath, options) {
         checkPrimitive(uvs, faceNormals);
 
         if (vertices.length === 3) {
-            const isWindingCorrect = checkWindingCorrect(positions[0], positions[1], positions[2], normals[0]);
             const index1 = addVertex(vertices[0], positions[0], uvs[0], normals[0]);
             const index2 = addVertex(vertices[1], positions[1], uvs[1], normals[1]);
             const index3 = addVertex(vertices[2], positions[2], uvs[2], normals[2]);
-            addTriangle(index1, index2, index3, isWindingCorrect);
+            addTriangle(index1, index2, index3, true);
         } else { // Triangulate if the face is not a triangle
             const points = scratchPoints;
             const vertexIndices = scratchVertexIndices;