Automatic merge of T1.5.1-870-ge0bf062eb and 18 pull requests

- Pull request #570 at 3539862: Experimental glTF 2.0 support with PBR lighting
- Pull request #839 at d00beb9: First phase of https://blueprints.launchpad.net/or/+spec/additional-cruise-control-parameters
- Pull request #876 at f92de76: docs: add source for documents previously on website to source Documentation folder
- Pull request #882 at 9c456aa: Blueprint/train car operations UI window
- Pull request #885 at 8f94333: feat: Add notifications to Menu
- Pull request #886 at 6c0785b: Scene viewer extension to TrackViewer
- Pull request #892 at 1f5ba4c: Signal Function OPP_SIG_ID_TRAINPATH
- Pull request #896 at 5866028: First implementation of https://blueprints.launchpad.net/or/+spec/specific-sounds-for-ai-trains
- Pull request #897 at 42f1dd9: feat: Improved system information collection
- Pull request #903 at 9bead33: Downloading route content (Github, zip)
- Pull request #907 at 9b0b04f: Bug fix for https://bugs.launchpad.net/or/+bug/2047300 Dynamic tracks disappear after long tunnel
- Pull request #911 at 6834af0: docs: Add refactoring as a special type of PR
- Pull request #912 at d595703: New Triple Valve Features Vol. 2
- Pull request #914 at 2ffadd6: Adjustments to Duplex steam
- Pull request #915 at 6d911d7: Correct calculation error with curve friction
- Pull request #917 at 3bbf66e: Lighting Configuration Enhancements
- Pull request #919 at a3c907f: Added mouse wheel support for controls which can be moved by pressing t…
- Pull request #920 at a94e403: Update RailDriver in Manual

Author: openrails-bot

Source/Documentation/Manual/images/options-raildriver-assignment.png

@@ -505,32 +505,82 @@ By clicking on *Export* a printable text file ``Open Rails
 Keyboard.txt`` is generated on the desktop, showing all links between
 commands and keys.
 
+
 RailDriver Options
 ==================
 
+Open Rails has built-in support for the RailDriver controller from P.I.Engineering so
+you do not need any extra software for the RailDriver to work with Open Rails.
+
+If your RailDriver is connected, you should see a RailDriver tab in the options menu:
+
 .. image:: images/options-raildriver.png
 
-This tab allows configuring a RailDriver device. In this panel you will
-find listed the RailDriver buttons that are associated
-with all ORTS commands.
 
-You can modify them by clicking on a field and pressing the new desired
-button. Three symbols will appear at the right of the field: with the first
-one you validate the change, with the second one you cancel it, with the
-third one you return to the default value.
+Use this tab to calibrate the 6 analog controls and assign operations to the
+44 switches on your RailDriver device.
 
-By clicking on *Check* ORTS verifies that the changes made are compatible,
-that is, that there is no button that is used for more than one command.
 
-By clicking on *Defaults* all changes that were made are reset, and the
-default values are reloaded.
+Calibrating RailDriver Levers
+-----------------------------
+RailDriver uses analog inputs that appear to vary from unit to unit.  
+In theory the range of each lever is 0-255 but, in practice, the actual range can be much narrower. 
+For this reason Open Rails uses a calibration routine to adjust to the actual range of each lever.
 
-By clicking on *Export* a printable text file ``Open Rails
-RailDriver.txt`` is generated on the desktop, showing all links between
-commands and buttons.
+You will need to calibrate the RailDriver, even if you’ve previously calibrated your RailDriver in other software.
+However, you will only need to perform a full calibration once as Open Rails will use that calibration from then on.
+
+Click the Callibration button and follow the prompts:
+
+.. image:: images/options-raildriver-calibration-message.png
+
+Note the image on screen will also visually guide you to the control being calibrated as in this example:
+
+.. image:: images/options-raildriver-calibration.png
+
+You will be prompted in sequence to calibrate all 6 of the RailDriver analog controls:
+
+- Reverser
+- Throttle
+- Automatic Brake
+- Independent Brake
+- Light/wiper switches
+
+If you make a mistake during calibration, simply restart the process again.
+
+
+Assigning RailDriver Switches
+-----------------------------
+
+You can modify the assignments by clicking on a field (e.g. "Pause") and pressing the
+RailDriver button you want for that operation.
+Three symbols will appear at the right of the field: use them to validate the change, 
+cancel it or restore the default value.
+
+.. image:: images/options-raildriver-assignment.png
+
+
+Other controls on this tab
+--------------------------
+
+Click on *Check* to verify that the changes made are compatible;
+that is, that no button is used for more than one command.
+
+Click on *Defaults* to reset all the assignments.
+
+Click on *Export* to generate a report file ``Open Rails
+RailDriver.txt`` on the desktop, listing all links between
+commands and switches.
+
+
+Using your RailDriver from within Open Rails
+--------------------------------------------
+
+To engage the RailDriver, use the Open Rails function named “Game External Controller (Raildriver)”.
+By default this is assigned to the backtick key (` )
+
+You can look up this function’s keybinding in-game by using the F1 help screen.
 
-By clicking on *Calibrate* a guided procedure will be started to
-calibrate all RailDriver levers.
 
 Data Logger Options
 ===================