improved background gradient

modules/viz/include/opencv2/viz/viz3d.hpp

@@ -100,6 +100,7 @@ namespace cv
             void setFullScreen(bool mode = true);
             void setBackgroundColor(const Color& color = Color::black());
             void setBackgroundTexture(InputArray image = noArray());
+            void setBackgroundGradient(const Color& up, const Color& down);
             void setBackgroundMeshLab();
 
             void spin();

modules/viz/src/viz3d.cpp

@@ -137,6 +137,7 @@ void cv::viz::Viz3d::saveScreenshot(const String &file) { impl_->saveScreenshot(
 void cv::viz::Viz3d::setWindowPosition(const Point& window_position) { impl_->setWindowPosition(window_position); }
 void cv::viz::Viz3d::setFullScreen(bool mode) { impl_->setFullScreen(mode); }
 void cv::viz::Viz3d::setBackgroundColor(const Color& color) { impl_->setBackgroundColor(color); }
+void cv::viz::Viz3d::setBackgroundGradient(const Color& up, const Color& down) { impl_->setBackgroundGradient(up, down); }
 
 void cv::viz::Viz3d::setBackgroundTexture(InputArray image) { impl_->setBackgroundTexture(image); }
 void cv::viz::Viz3d::setBackgroundMeshLab() {impl_->setBackgroundMeshLab(); }

modules/viz/src/vizimpl.cpp

@@ -302,6 +302,21 @@ void cv::viz::Viz3d::VizImpl::setBackgroundColor(const Color& color)
 {
     Color c = vtkcolor(color);
     renderer_->SetBackground(c.val);
+    renderer_->GradientBackgroundOff();
+}
+
+void  cv::viz::Viz3d::VizImpl::setBackgroundGradient(const Color& up, const Color& down)
+{
+    Color vtkup = vtkcolor(up), vtkdown = vtkcolor(down);
+    renderer_->SetBackground(vtkdown.val);
+    renderer_->SetBackground2(vtkup.val);
+    renderer_->GradientBackgroundOn();
+}
+
+//////////////////////////////////////////////////////////////////////////////////////////////
+void cv::viz::Viz3d::VizImpl::setBackgroundMeshLab()
+{
+    setBackgroundGradient(Color(2, 1, 1), Color(240, 120, 120));
 }
 
 //////////////////////////////////////////////////////////////////////////////////////////////
@@ -329,30 +344,6 @@ void cv::viz::Viz3d::VizImpl::setBackgroundTexture(InputArray image)
     renderer_->TexturedBackgroundOn();
 }
 
-//////////////////////////////////////////////////////////////////////////////////////////////
-void cv::viz::Viz3d::VizImpl::setBackgroundMeshLab()
-{
-    static Color up(2, 1, 1), down(240, 120, 120);
-    static Mat meshlab_texture;
-
-    if (meshlab_texture.empty())
-    {
-        meshlab_texture.create(2048, 2048, CV_8UC4);
-
-        for (int y = 0; y < meshlab_texture.rows; ++y)
-        {
-            double alpha = (y+1)/(double)meshlab_texture.rows;
-            Vec4b color = up * (1 - alpha) + down * alpha;
-
-            Vec4b *row = meshlab_texture.ptr<Vec4b>(y);
-            for(int x = 0; x < meshlab_texture.cols; ++x)
-                row[x] = color;
-        }
-
-    }
-    setBackgroundTexture(meshlab_texture);
-}
-
 /////////////////////////////////////////////////////////////////////////////////////////////
 void cv::viz::Viz3d::VizImpl::setCamera(const Camera &camera)
 {

modules/viz/src/vizimpl.hpp

@@ -110,7 +110,7 @@ public:
     void setFullScreen(bool mode);
     String getWindowName() const;
     void setBackgroundColor(const Color& color);
-
+    void setBackgroundGradient(const Color& up, const Color& down);
     void setBackgroundTexture(InputArray image);
     void setBackgroundMeshLab();
 

modules/viz/test/test_viz3d.cpp

@@ -51,8 +51,9 @@ TEST(Viz_viz3d, develop)
     //theRNG().fill(mesh.colors, RNG::UNIFORM, 0, 255);
 
     cv::viz::Viz3d viz("abc");
-    viz.setBackgroundColor(cv::viz::Color::mlab());
+    viz.setBackgroundMeshLab();
     viz.showWidget("coo", cv::viz::WCoordinateSystem(1));
+    viz.showWidget("cloud", cv::viz::WCloud(cloud));
 
     //viz.showWidget("h", cv::viz::Widget::fromPlyFile("d:/horse-red.ply"));
     //viz.showWidget("a", cv::viz::WArrow(cv::Point3f(0,0,0), cv::Point3f(1,1,1)));