From 59fb96edf2f5e110f0fe2f7ca71e071af358ccf3 Mon Sep 17 00:00:00 2001
From: hpinkos <pinkos.hannah@gmail.com>
Date: Tue, 16 May 2017 10:32:05 -0400
Subject: [PATCH 1/2] Clone polyline collection model matrix on update

---
 Source/Scene/Polyline.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Source/Scene/Polyline.js b/Source/Scene/Polyline.js
index f73352d37eca..9572cd0e8152 100644
--- a/Source/Scene/Polyline.js
+++ b/Source/Scene/Polyline.js
@@ -335,7 +335,7 @@ define([
             this._boundingVolumeWC = BoundingSphere.transform(this._boundingVolume, modelMatrix, this._boundingVolumeWC);
         }
 
-        this._modelMatrix = modelMatrix;
+        this._modelMatrix = Matrix4.clone(modelMatrix, this._modelMatrix);
 
         if (this._segments.positions.length !== segmentPositionsLength) {
             // number of positions changed

From 5afc8a3d8ab2155b94e7a0fe862bd6447dbd1614 Mon Sep 17 00:00:00 2001
From: hpinkos <pinkos.hannah@gmail.com>
Date: Tue, 16 May 2017 15:05:18 -0400
Subject: [PATCH 2/2] specs

---
 CHANGES.md                            |  1 +
 Source/Core/PolylinePipeline.js       |  4 ++--
 Specs/Scene/PolylineCollectionSpec.js | 22 ++++++++++++++++++++++
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/CHANGES.md b/CHANGES.md
index fca485899fcb..ca04edd999a9 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -24,6 +24,7 @@ Change Log
 * Fixed bug in conversion formula in `Matrix3.fromHeadingPitchRoll`. [#5195](https://github.com/AnalyticalGraphicsInc/cesium/issues/5195)
 * Upgrade FXAA to version 3.11. [#5200](https://github.com/AnalyticalGraphicsInc/cesium/pull/5200)
 * `Scene.pickPosition` now caches results per frame to increase performance. [#5117](https://github.com/AnalyticalGraphicsInc/cesium/issues/5117)
+* Fixed bug where polylines would not update when `PolylineCollection` model matrix was updated [#5327](https://github.com/AnalyticalGraphicsInc/cesium/pull/5327)
 
 ### 1.32 - 2017-04-03
 
diff --git a/Source/Core/PolylinePipeline.js b/Source/Core/PolylinePipeline.js
index 01b9dab3a85c..96574e817fdb 100644
--- a/Source/Core/PolylinePipeline.js
+++ b/Source/Core/PolylinePipeline.js
@@ -152,9 +152,9 @@ define([
             var inverseModelMatrix = Matrix4.inverseTransformation(modelMatrix, wrapLongitudeInversMatrix);
 
             var origin = Matrix4.multiplyByPoint(inverseModelMatrix, Cartesian3.ZERO, wrapLongitudeOrigin);
-            var xzNormal = Matrix4.multiplyByPointAsVector(inverseModelMatrix, Cartesian3.UNIT_Y, wrapLongitudeXZNormal);
+            var xzNormal = Cartesian3.normalize(Matrix4.multiplyByPointAsVector(inverseModelMatrix, Cartesian3.UNIT_Y, wrapLongitudeXZNormal), wrapLongitudeXZNormal);
             var xzPlane = Plane.fromPointNormal(origin, xzNormal, wrapLongitudeXZPlane);
-            var yzNormal = Matrix4.multiplyByPointAsVector(inverseModelMatrix, Cartesian3.UNIT_X, wrapLongitudeYZNormal);
+            var yzNormal = Cartesian3.normalize(Matrix4.multiplyByPointAsVector(inverseModelMatrix, Cartesian3.UNIT_X, wrapLongitudeYZNormal), wrapLongitudeYZNormal);
             var yzPlane = Plane.fromPointNormal(origin, yzNormal, wrapLongitudeYZPlane);
 
             var count = 1;
diff --git a/Specs/Scene/PolylineCollectionSpec.js b/Specs/Scene/PolylineCollectionSpec.js
index 5540b0e6a7fa..0daf02c53669 100644
--- a/Specs/Scene/PolylineCollectionSpec.js
+++ b/Specs/Scene/PolylineCollectionSpec.js
@@ -7,6 +7,7 @@ defineSuite([
         'Core/DistanceDisplayCondition',
         'Core/HeadingPitchRange',
         'Core/Math',
+        'Core/Matrix4',
         'Scene/Camera',
         'Scene/Material',
         'Scene/SceneMode',
@@ -19,6 +20,7 @@ defineSuite([
         DistanceDisplayCondition,
         HeadingPitchRange,
         CesiumMath,
+        Matrix4,
         Camera,
         Material,
         SceneMode,
@@ -1371,6 +1373,26 @@ defineSuite([
 
     });
 
+    it('renders with model matrix', function() {
+        polylines.add({
+            positions : [{
+                x : 0.0,
+                y : 0.0,
+                z : 0.0
+            }, {
+                x : 0.0,
+                y : 1.0,
+                z : 0.0
+            }]
+        });
+
+        expect(scene).toRender([0, 0, 0, 255]);
+        scene.primitives.add(polylines);
+        expect(scene).toRender([0, 0, 0, 255]);
+        polylines.modelMatrix = Matrix4.fromUniformScale(1000000.0, polylines.modelMatrix);
+        expect(scene).notToRender([0, 0, 0, 255]);
+    });
+
     it('is picked', function() {
         var p = polylines.add({
             positions : [{