Added new functionalities to viz module

- load OBJ file
- set offscreen rendering
- set roll angle of the camera
- get Mat screenshot of the current scene
- remove all lights from the scene
- add a custom light in the scene
- modify the size of the WImage3D widget
- added ambient property for the widget

Changed Vec3d in cv::viz::Color

Renamed method getMatScreenshotin getScreenshot

Modified showWidget

Fixed on viz::Color and reverted fix on vtkProp3D

Removed cameraRoll method

Merged load mesh method (for ply and obj file)

Fixed doc

Fixed cv::viz::WImage3D::setSize for vtk5.8

Fixed enum for cv::viz::Mesh::load

modules/viz/include/opencv2/viz/types.hpp

@@ -119,6 +119,12 @@ namespace cv
         class CV_EXPORTS Mesh
         {
         public:
+            enum {
+                LOAD_AUTO = 0,
+                LOAD_PLY = 1,
+                LOAD_OBJ = 2
+            };
+
             Mat cloud, colors, normals;
 
             //! Raw integer list of the form: (n,id1,id2,...,idn, n,id1,id2,...,idn, ...)
@@ -127,11 +133,17 @@ namespace cv
 
             Mat texture, tcoords;
 
-            /** @brief Loads a mesh from a ply file.
+            /** @brief Loads a mesh from a ply or a obj file.
 
-            @param file File name (for now only PLY is supported)
+            @param file File name
+            @param type File type (for now only PLY and OBJ are supported)
+
+            **File type** can be one of the following:
+            -   **LOAD_PLY**
+            -   **LOAD_OBJ**
              */
-            static Mesh load(const String& file);
+            static Mesh load(const String& file, int type = LOAD_PLY);
+
         };
 
         /** @brief This class wraps intrinsic parameters of a camera.

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

@@ -189,6 +189,10 @@ namespace cv
              */
             String getWindowName() const;
 
+            /** @brief Returns the Mat screenshot of the current scene.
+            */
+            cv::Mat getScreenshot() const;
+
             /** @brief Saves screenshot of the current scene.
 
             @param file Name of the file.
@@ -224,6 +228,26 @@ namespace cv
              */
             void spinOnce(int time = 1, bool force_redraw = false);
 
+            /** @brief Create a window in memory instead of on the screen.
+             */
+            void setOffScreenRendering();
+
+            /** @brief Remove all lights from the current scene.
+            */
+            void removeAllLights();
+
+            /** @brief Add a light in the scene.
+
+            @param position The position of the light.
+            @param focalPoint The point at which the light is shining
+            @param color The color of the light
+            @param diffuseColor The diffuse color of the light
+            @param ambientColor The ambient color of the light
+            @param specularColor The specular color of the light
+             */
+            void addLight(Vec3d position, Vec3d focalPoint = Vec3d(0, 0, 0), Color color = Color::white(),
+                          Color diffuseColor = Color::white(), Color ambientColor = Color::black(), Color specularColor = Color::white());
+
             /** @brief Returns whether the event loop has been stopped.
             */
             bool wasStopped() const;

modules/viz/include/opencv2/viz/widgets.hpp

@@ -66,7 +66,8 @@ namespace cv
             FONT_SIZE,
             REPRESENTATION,
             IMMEDIATE_RENDERING,
-            SHADING
+            SHADING,
+            AMBIENT
         };
 
         enum RepresentationValues
@@ -136,6 +137,7 @@ namespace cv
             -   **OPACITY**
             -   **LINE_WIDTH**
             -   **FONT_SIZE**
+            -   **AMBIENT**
             -
             **REPRESENTATION**: Expected values are
             :   -   **REPRESENTATION_POINTS**
@@ -494,6 +496,12 @@ namespace cv
             @param image BGR or Gray-Scale image.
              */
             void setImage(InputArray image);
+
+            /** @brief Sets the image size of the widget.
+
+            @param size the new size of the image.
+             */
+            void setSize(const Size& size);
         };
 
         /////////////////////////////////////////////////////////////////////////////