diff --git a/packages/reshader.gl/src/shaderlib/glsl/fbo_picking.vert b/packages/reshader.gl/src/shaderlib/glsl/fbo_picking.vert
index 9d18695a84..53bcad81c4 100644
--- a/packages/reshader.gl/src/shaderlib/glsl/fbo_picking.vert
+++ b/packages/reshader.gl/src/shaderlib/glsl/fbo_picking.vert
@@ -16,26 +16,26 @@
 #ifdef ENABLE_PICKING
 //HAS_PICKING_ID == 1 时读取attributes
 #if HAS_PICKING_ID == 1
-attribute float aPickingId;
+    attribute float aPickingId;
 //HAS_PICKING_ID == 2 时读取uniforms
 #elif HAS_PICKING_ID == 2
-uniform float uPickingId;
+    uniform float uPickingId;
 #endif
-varying float vPickingId;
-varying float vFbo_picking_viewZ;
-varying float vFbo_picking_visible;
+    varying float vPickingId;
+    varying float vFbo_picking_viewZ;
+    varying float vFbo_picking_visible;
 #endif
-varying float vFbo_picking_fragDepth;
+    varying float vFbo_picking_fragDepth;
 
 void fbo_picking_setData(float viewPosZ, bool visible) {
     #ifdef ENABLE_PICKING
     #if HAS_PICKING_ID == 1
-       vPickingId = aPickingId;
+        vPickingId = aPickingId;
     #elif HAS_PICKING_ID == 2
         vPickingId = uPickingId;
     #endif
         vFbo_picking_viewZ = viewPosZ;
+        vFbo_picking_visible = visible ? 1.0 : 0.0;
     #endif
-    vFbo_picking_visible = visible ? 1.0 : 0.0;
     vFbo_picking_fragDepth = viewPosZ + 1.0;
 }
diff --git a/packages/vt/src/layer/plugins/painters/Painter.js b/packages/vt/src/layer/plugins/painters/Painter.js
index 9e7bbef802..4bad6e07a6 100644
--- a/packages/vt/src/layer/plugins/painters/Painter.js
+++ b/packages/vt/src/layer/plugins/painters/Painter.js
@@ -1117,6 +1117,7 @@ class Painter {
             const pickingVert = this.picking[i].getPickingVert();
             const wgslPickingVert = this.picking[i].getPickingWGSLVert();
             const defines = {
+                'PICKING_MODE': 1,
                 'ENABLE_PICKING': 1,
                 'HAS_PICKING_ID': 1
             };
diff --git a/packages/vt/test/specs/update.vector.spec.js b/packages/vt/test/specs/update.vector.spec.js
index e592e0bc5c..c2a25a441d 100644
--- a/packages/vt/test/specs/update.vector.spec.js
+++ b/packages/vt/test/specs/update.vector.spec.js
@@ -1356,6 +1356,44 @@ describe('vector layers update style specs', () => {
         }, 500);
     });
 
+    it('PolygonLayer in GroupGLLayer can outline polygon', done => {
+        const polygon = new maptalks.Polygon(
+            [[[-1, 1], [1, 1], [1, -1], [-1, -1], [-1, 1]]],
+            {
+                id: 'foo',
+                symbol: {
+                    lineColor: "#e5e5e5",
+                    lineWidth: 1,
+                    polygonFill: '#0ff'
+                }
+            });
+        const layer = new PolygonLayer('vector', polygon);
+        const sceneConfig = {
+            postProcess: {
+                enable: true,
+                outline: {
+                    enable: true,
+                    outlineFactor: 0.3,
+                    highlightFactor: 0.2,
+                    outlineWidth: 1,
+                    outlineColor: [1,0,0]
+                }
+            }
+        };
+        const group = new GroupGLLayer('group', [layer], { sceneConfig });
+        const renderer = map.getRenderer();
+        const x = renderer.canvas.width, y = renderer.canvas.height;
+        group.addTo(map);
+        setTimeout(() => {
+            layer.outline(['foo']);
+            setTimeout(() => {
+                const pixel = readPixel(layer.getRenderer().canvas, x / 2, y / 2);
+                assert(pixel[0] > 10);
+                done();
+            }, 500);
+        }, 500);
+    });
+
     it('line should can hide and show', done => {
         const line = new maptalks.LineString([[-1, 0], [1, 0]]);
         const layer = new LineStringLayer('vector', line, {
@@ -2066,15 +2104,11 @@ describe('vector layers update style specs', () => {
         const layer = new LineStringLayer('lines', [line]);
         const polygonLayer = new PolygonLayer('polygons', [polygon]);
         const group = new GroupGLLayer('group', [layer, polygonLayer]);
-        let count = 0;
         const canvas = map.getRenderer().canvas;
-        group.on('layerload', () => {
-            count++;
-            if (count === 1) {
-                const expectedPath = path.join(__dirname, 'fixtures', 'line-altitude', 'expected.png');
-                compareExpected(canvas, { expectedPath }, done);
-            }
-        });
+        setTimeout(() => {
+            const expectedPath = path.join(__dirname, 'fixtures', 'line-altitude', 'expected.png');
+            compareExpected(canvas, { expectedPath }, done);
+        }, 500);
         group.addTo(map);
     });