Add existing to tracked

node_modules/@cesium/engine/Source/Shaders/VectorTileVS.glsl

@@ -0,0 +1,9 @@
+in vec3 position;
+in float a_batchId;
+
+uniform mat4 u_modifiedModelViewProjection;
+
+void main()
+{
+    gl_Position = czm_depthClamp(u_modifiedModelViewProjection * vec4(position, 1.0));
+}