Finish Travis hacks

tests/src/3d/testqgs3drendering.cpp

@@ -127,9 +127,13 @@ void TestQgs3DRendering::testFlatTerrain()
 
   // look from the top
   scene->cameraController()->setLookingAtPoint( QgsVector3D( 0, 0, 0 ), 2500, 0, 0 );
+
+  // When running the test on Travis, it would initially return empty rendered image.
+  // Capturing the initial image and throwing it away fixes that. Hopefully we will
+  // find a better fix in the future.
+  Qgs3DUtils::captureSceneImage( engine, scene );
+
   QImage img = Qgs3DUtils::captureSceneImage( engine, scene );
-  //QTest::qSleep( 100 );  // a hack to avoid blank render on Travis
-  img = Qgs3DUtils::captureSceneImage( engine, scene );
   QVERIFY( renderCheck( "flat_terrain_1", img, 40 ) );
 
   // tilted view (pitch = 60 degrees)
@@ -162,9 +166,13 @@ void TestQgs3DRendering::testDemTerrain()
   engine.setRootEntity( scene );
 
   scene->cameraController()->setLookingAtPoint( QgsVector3D( 0, 0, 0 ), 2000, 60, 0 );
+
+  // When running the test on Travis, it would initially return empty rendered image.
+  // Capturing the initial image and throwing it away fixes that. Hopefully we will
+  // find a better fix in the future.
+  Qgs3DUtils::captureSceneImage( engine, scene );
+
   QImage img3 = Qgs3DUtils::captureSceneImage( engine, scene );
-  QTest::qSleep( 100 );  // a hack to avoid blank render on Travis
-  img3 = Qgs3DUtils::captureSceneImage( engine, scene );
 
   QVERIFY( renderCheck( "dem_terrain_1", img3, 40 ) );
 }