Added move camera to model service (#1823)

Signed-off-by: Alejandro Hernández Cordero <ahcorde@gmail.com>

Author: ahcorde

tutorials.md.in

@@ -41,6 +41,7 @@ Ignition @IGN_DESIGNATION_CAP@ library and how to use the library effectively.
 * \subpage spherical_coordinates "Spherical coordinates": Working with latitude and longitude
 * \subpage python_interfaces Python interfaces
 * \subpage headless_rendering "Headless rendering": Access the GPU on a remote machine to produce sensor data without an X server.
+* \subpage move_camera_to_model Move camera to model
 
 **Migration from Gazebo classic**
 

tutorials/files/move_camera_to_model/box_20.png

@@ -0,0 +1,28 @@
+\page move_camera_to_model Move Camera to model
+
+This tutorial gives an introduction to Gazebo's service `/gui/move_to/model`. This service will allow to move the camera to a specific model taking into account distance to the model and camera angle.
+
+## How to move the camera to a model
+
+1. Load the **View Angle** plugin. This service is only available when the **View Angle** plugin is loaded.
+2. Call the service using the request message type `ignition.msgs.GUICamera` and the response message type `ignition.msgs.Boolean`. The distance to the object is defined as the z coordinate, and the direction of the camera with a quaternion. It's possible to select the projection type.
+
+For example, Let's move the camera to the `box` model looking down from 5 meters away.
+
+```bash
+ign service  -s /gui/move_to/model --reqtype ignition.msgs.GUICamera  --reptype ignition.msgs.Boolean -r 'name: "box", pose: {position: {z:5}, orientation: {x:0, y:0, z: -1, w:0}}, projection_type: "orbit"' --timeout 5000
+```
+
+@image html files/move_camera_to_model/box_5.gif
+
+The camera can also be placed far away, for example 20 meters:
+
+```bash
+ign service  -s /gui/move_to/model --reqtype ignition.msgs.GUICamera  --reptype ignition.msgs.Boolean -r 'name: "box", pose: {position: {z:20}, orientation: {x:0, y:0, z: -1, w:0}}, projection_type: "orbit"' --timeout 5000
+```
+
+@image html files/move_camera_to_model/box_20.gif
+
+In the following gif you can see the workflow of this service:
+
+@image html files/move_camera_to_model/move_to_model.gif