From 4f60137843ac7b32b489237eaf9f17ccea33e03c Mon Sep 17 00:00:00 2001
From: Nicholas Barlow <whoisdrigax@gmail.com>
Date: Thu, 9 Apr 2020 17:20:05 -0700
Subject: [PATCH] invert KHR_texture_transform vScale, due to babylon using a
 bottom left texture coordinate origin, and glTF expecting a top left
 coordinate origin (#802)

---
 SharedProjects/Babylon2GLTF/GLTFExporter.Texture.cs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/SharedProjects/Babylon2GLTF/GLTFExporter.Texture.cs b/SharedProjects/Babylon2GLTF/GLTFExporter.Texture.cs
index 3972517a..034d4092 100644
--- a/SharedProjects/Babylon2GLTF/GLTFExporter.Texture.cs
+++ b/SharedProjects/Babylon2GLTF/GLTFExporter.Texture.cs
@@ -448,9 +448,9 @@ private void AddTextureTransformExtension(ref GLTF gltf, ref GLTFTextureInfo glt
 
             KHR_texture_transform textureTransform = new KHR_texture_transform
             {
-                offset = new float[] { babylonTexture.uOffset, babylonTexture.vOffset },
+                offset = new float[] { babylonTexture.uOffset, -babylonTexture.vOffset },
                 rotation = angle,
-                scale = new float[] { babylonTexture.uScale, babylonTexture.vScale },
+                scale = new float[] { babylonTexture.uScale, -babylonTexture.vScale },
                 texCoord = babylonTexture.coordinatesIndex
             };