Camera shot

Screenshots during a simulation.

Collaboration diagram for Camera shot:

CCameraShot takes screenshots during a simulation. This can be either a single screenshot or a series at given framerate to create a video. The screenshots are saved to file.

To create a video, ffmpeg can be used, for example using the following command:

ffmpeg -i shot%d.png -r 30 -c:v libx264 -x264opts crf=20 video.avi

Author

Karl-Johan Reite

Example configuration excerpt

<!-- To generate video: ffmpeg -i shot%d.png -r 30 -c:v libx264 -x264opts crf=20 video.avi -->
<Lib
    LibName                     = "fhsim_base"
    SimObject                   = "Camera/Shot"
    Name                        = "camshot"
    Filename                    = "shot1.png"
    Start                       = "0"
    Video                       = "1"
    Stop                        = "260"
    FrameRateControl            = "FPS"
    FrameRateValue              = "30"
    Refinement                  = "1"
    Path                        = ""
/>

Name	Width	Description
Pos1	3	The position of the first target.
PosN1	3	The position of the N'th target.

Output Ports

No output ports available.

Configuration parameters

Name	Width	Description
Filename	1	The base name of the file, e.g. shot.png. This will be expanded to shotN.png, where N is the frame index.
Start	1	The time (in seconds from simulation start) to take the first shot.
Video	1	A bool telling if a series or only a single shot should be taken.
Stop	1	The time to stop taking screenshots.
FrameRateControl	1	Should be either FPS (Frames Per Second simulationtime) or SPF (Steps Per Frame). Default is FPS.
FrameRateValue	1	Framrate, in frames per second. Default is 24.
Refinement	1	The screenshot is created by tiling this number of screenshots vertical and horizontal, increasing the reolution of the screenshot.
Path	1	The path to the screenshots. If empty (the default), the screenshots will be placed in screenshots/<time_string>.

Initial conditions

This SimObject contains no initial conditions.

Full example file

<Contents>
  <OBJECTS>
    <Lib
      LibName     = "fhsim_base"
      SimObject   = "Camera/Controller2"
      Name        = "CAM"
      NumInput    = "4"
      Time        = "0,1,2,3"
      UseDegrees  = "1"
      Interpolate ="1"
    />
    <Lib
      LibName         = "base"
      SimObject       = "Body/Mass"
      Name            = "M1"
      Scale           = "1"
      Mass            = "1"
      Material        = "Simple/Red"
    />
    <Lib
      LibName         = "base"
      SimObject       = "Body/Mass"
      Name            = "M2"
      Scale           = "1"
      Mass            = "1"
      Material        = "Simple/Green"
    />
    <Lib
      LibName         = "base"
      SimObject       = "Body/Mass"
      Name            = "M3"
      Scale           = "1"
      Mass            = "1"
    />
    <Lib
      LibName         = "base"
      SimObject       = "Body/Mass"
      Name            = "M4"
      Scale           = "1"
      Mass            = "1"
      Material        = "Simple/Black"
    />
<Lib
      LibName                     = "fhsim_base"
      SimObject                   = "Camera/Shot"
      Name                        = "camshot"
      Filename                    = "shot.png"
      Start                       = "0"
      Video                       = "1"
      Stop                        = "5"
      FrameRateControl            = "FPS"
      FrameRateValue              = "30"
      Refinement                  = "1"
      Path                        = ""
    />
    <Lib
        LibName         = "base"
        SimObject       = "DefaultEnvironment"
        Name            = "Env"
        Seadepth        = "500"
        Density         = "1000"
        CurrentVelocity = "0,0,0"
    />
  </OBJECTS>
 
  <INTERCONNECTIONS>
    <Connection
       CAM.Position1 = "-10,0,0"
       CAM.Position2 = "0,-10,0"
       CAM.Position3 = "10,0,0"
       CAM.Position4 = "0,10,0"
       CAM.Pitch1    = "0"
       CAM.Pitch2    = "0"
       CAM.Pitch3    = "0"
       CAM.Pitch4    = "0"
       CAM.Yaw1      = "0"
       CAM.Yaw2      = "90"
       CAM.Yaw3      = "180"
       CAM.Yaw4      = "270"
 
       M1.Force = "0,0,0"
       M2.Force = "0,0,0"
       M3.Force = "0,0,0"
       M4.Force = "0,0,0"
    />
  </INTERCONNECTIONS>
 
  <INITIALIZATION>
    <InitialCondition
        M1.Pos = "0,0,0"
        M2.Pos = "10,-20,0"
        M3.Pos = "20,-10,0"
        M4.Pos = "-10,20,0"
        M1.Vel = "0,0,0" 
        M2.Vel = "0,0,0" 
        M3.Vel = "0,0,0" 
        M4.Vel = "0,0,0" 
    />
  </INITIALIZATION>
 
  <INTEGRATION>
    <Engine
    IntegratorMethod           = "2"
    NumCores                   = "1"
    TOutput                    = "0,5"
    LogStates                  = "1"  
    stepsize                   = "0"
    HMax                       = "0.002"
    HMin                       = "0.00000001"
    AbsTol                     = "1e-3" 
    RelTol                     = "1e-3"
    UseRSSNormInsteadOfInfNorm = "0"
    FileOutput                 = "objects:all"
    />
  </INTEGRATION>
</Contents>

This SimObject is referred to as Camera/Shot