Add existing to tracked

node_modules/@cesium/engine/Source/Shaders/ViewportQuadFS.js

@@ -0,0 +1,18 @@
+//This file is automatically rebuilt by the Cesium build process.
+export default "\n\
+in vec2 v_textureCoordinates;\n\
+\n\
+void main()\n\
+{\n\
+    czm_materialInput materialInput;\n\
+    \n\
+    materialInput.s = v_textureCoordinates.s;\n\
+    materialInput.st = v_textureCoordinates;\n\
+    materialInput.str = vec3(v_textureCoordinates, 0.0);\n\
+    materialInput.normalEC = vec3(0.0, 0.0, -1.0);\n\
+    \n\
+    czm_material material = czm_getMaterial(materialInput);\n\
+\n\
+    out_FragColor = vec4(material.diffuse + material.emission, material.alpha);\n\
+}\n\
+";