This topic describes how to implement video mapping of moving panels thanks to motor encoder feedback.
      See also 
                    Introduction
                            Posital is a manufacturer of sensors and encoders. It is ofently use in show industrie to create rotating or mooving video-mapped structure.
        
                            The sensors communicate a signal to Smode through network thanks differents prerequisites applications: a Firefox 3.5 and an old version of Java
        
                            You can download thoses applications here:
        
http://download.smode.fr/utilities/FRABA%20POSITAL%20PREREQUIST/
                     
                    
                    Usecase #1: Moving Panels
                            Smode will receive meters value from a Incremental Rotary Encoders.
        
                            But the panels have a 
                    
                      start position
                     and an 
                    
                      end position
                     in your show.
        
                            So, you will receive values in metres corresponding to these positions.
        
                            Every panel is connected to a sensor, so you will have to create a 
                    Link
                    A link from a source parameter to a set of Link Target
                    Read More
                     for each sensor.
        
                            The process will be this one:
        
 
                    
                    
                            On stage, you may be surprised by some changes made to the position of the video projectors, their focal lengths, panel dimensions, etc.
        
                            This is why we advise you to use a 
                    
                      2D video mapping technique
                     and mostly the 
                    Perspective Interpolation
                    Interpolation between two different perspective placements
                    Read More
                     as mapping tool.
        
 
                    
                            This 
                    2D Placement
                    Define a placement in 2D space
                    Read More
                     type allows you to define a starting distorsion and a ending distorsion and it automatically distorts the layer through a percentage.
        
                            Once every layer that will be mapped to your panel are in 
                    Perspective Interpolation
                    Interpolation between two different perspective placements
                    Read More
                    , you can create 
                    Link
                    A link from a source parameter to a set of Link Target
                    Read More
                     for each Posital values you'll receive and apply a 
                    To Percentage
                    Change the Input number and bind it into a percentage range that goes from 0 to 100%
                    Read More
                     modifier on the link.
        
                            This 
                    Link Modifier
                    add operations between source and target from a link
                    Read More
                     will convert a start and end values to percentage. Those values will be the starting and the ending valuesof your panel.
        
                            Create a percentage 
                    Exposed Parameter
                    Allow to control multiple Link Target with a single value
                    Read More
                     for each panel and 
                    
                                connect the current position of the 
                      Perspective Interpolation
                      Interpolation between two different perspective placements
                      Read More
                       to this percentage
        
                    
                            The perspective interpolation allows you to choose a starting and ending percentage value.
        Between thoses values, Smode will interpolate the deformation you set as start and end and beyond them, Smode will extrapolate.
        
                    
 
                    
                            Once you have 
                    Configure Network for posital
                    Configure the network for Posital sensors
                    Read More
                    :
        
                            In the 
                    To Percentage
                    Change the Input number and bind it into a percentage range that goes from 0 to 100%
                    Read More
                    , set the min and max values depending on the movement of your panels (you may ask to the people in charge to moove the panels).
        
                    
                      - 
                        Move the panel to the starting position
                      
- 
                        Set the min value
                      
- 
                        Move the panel to the ending position
                      
- 
                        Set the max value
                      
                            You can now start the mapping step like this:
        
                    
                      - 
                        Move the panel to the starting position
                      
- 
                        Change the Placement 1 points
                      
- 
                        Move the panel to the ending position
                      
- 
                        Change the Placement 2 points
                      
                            repeat this process for each panel and the job is done!
      
 
                    
                    Usecase #2: Moving Panels with two crossed video-projectors
                     
                    
                            In this case, both video projector use a 2D mapping projection thanks the 
                    Perspective Interpolation
                    Interpolation between two different perspective placements
                    Read More
                    .
        
                            The ending point of the video projector on the left will be the starting point of the projector on the right.