FCurveEditor
 
 
 

FCurveEditor

Object Hierarchy

Introduced

v3.0

Description

This object provides the context information of the Softimage FCurve editor. By using the information exposed by this object, it is possible to write custom fcurve editing scripts or plug-ins which react to user's actions in the FCurve Editor.

In order to access an instance of this object you need to create a custom command with the siCommandCategory set to siFCurveCategory. This command will appear in the edit menu of the fcurve editor so that the user can execute it on demand. The command takes a single argument, which is a pointer to an instance of the FCurveEditor object.

Using the methods and properties of the FCurve and FCurveKey objects the custom command can change the fcurves. The user interface will update automatically to reflect any changes made to the underlying fcurve objects.

The following example demonstrates two custom fcurve editor scripts, and there are more examples in Netview, under XSI Local: Tools: Animate.

Methods

GetEditorAttribute2 GetSelectedKeys2    
       

Properties

EditorAttribute SelectedFCurves SelectedKeys  
       

Examples

VBScript Example

'
' Custom FCurve Command Demo
'
'This script demontrates the Softimage support for plugging in a 
'custom command.
'
'Instructions:
'
'1) In order to try this code the commands needs to be saved onto disk in a .vbs 
'file so that it can be registered.
'
'2) install the commands using the following, (changing the path according to your config):
'  xsi -script "C:/temp/FCurveDemo.vbs" -main InstallFCurveCmdExamples -args -Location "c:/temp/FCurveDemo.vbs"
'
'3) Launch Softimage, 
'4) Create some animated parameters, 
'5) Open the fcurve editor, select curves and keys from your animated parameters
'6) Try the FCurveEditorInfo and AvgSelectedPoints commands which will appear in the Edit menu
sub InstallFCurveCmdExamples( Location )
        dim cmd
        'Location argument is expected to be the full path name of the script file 
        'where the commands we are installing are implemented
        logmessage "Installing fcurve editor commands found in " & Location
        'Remove any existing earlier registrations of this command
        Application.RemoveCommand "FCurveEditorInfo"            
        Application.RemoveCommand "AvgSelectedPoints" 
        set cmd = Application.CreateCommand("FCurveEditorInfo", siFCurveCategory)
        cmd.Description = "FCurveEditorInfo shows information about FCurve Context"
        cmd.ScriptingName = "FCurveEditorInfo"
        cmd.Handler = "OnFCurveEditorInfo"
        cmd.FileName = Location
        cmd.Language = "VBScript"
        'FCurve callbacks are a sub not a function
        cmd.ReturnValue = false                                                                                 
        'FCurve commands get a pointer to an FCurveEditor OM object
        cmd.Arguments.Add "FCurveEditor", siArgumentInput, 0, siDispatch
        Application.AddCommand cmd
        logmessage "FCurveEditorInfo is now added to fcurve editor Edit menu"
        set cmd = Application.CreateCommand("AvgSelectedPoints", siFCurveCategory)
        cmd.Description = "AvgSelectedPoints change value of selected keys"
        cmd.ScriptingName = "AvgSelectedPoints"
        cmd.Handler = "OnAvgSelectedPoints"
        cmd.FileName = Location
        cmd.Language = "VBScript"
        cmd.ReturnValue = false                                                                                 
        cmd.Arguments.Add "FCurveEditor", siArgumentInput, 0, siDispatch
        Application.AddCommand cmd
        logmessage "AvgSelectedPoints is now added to fcurve editor Edit menu"
end sub
'This first demo is informative - it logs a bunch of information about the 
'state of the FCurve editor, in effect demonstrating what you can find out
sub OnFCurveEditorInfo( in_objFCurveEditor )
        LogMessage "FCurveEditorInfo called - showing information about current context of FCurve Editor"
        if ( typename( in_objFCurveEditor ) = "Nothing" ) then
                Logmessage "FCurve Argument is NULL"
        elseif ( typename( in_objFCurveEditor ) <> "FCurveEditor" ) then
                LogMessage "FCurve Argument is not an FCurve, it is a " & typename( in_objFCurveEditor ) 
        else            
                'Now access the FCurve Context listing the contents.
                dim oCurves, oCurve
                set oCurves = in_objFCurveEditor.SelectedFCurves
                if ( oCurves.Count = 0 ) then
                        logmessage "There are no selected fcurves in the editor"
                end if
                dim i, strInfo
                for each oCurve in oCurves
                        logmessage "-------------------------------------"
                        'build a string description of the frame/keyvalues 
                        '(for a real motion capture fcurve this would be too long to display like this)
                        strInfo = ""
                        for i = 0 to ( oCurve.Keys.Count - 1 )
                                strInfo = strInfo & "(" & Round( oCurve.Keys.Item( i ).Time, 3 ) _
                                                        & ", " & Round( oCurve.Keys.Item( i ).Value, 3 ) & ") "
                        next            
                        LogMessage "Selected FCurve has the following keys: " & strInfo
                        'List the selected keys
                        dim oKeys, oKey
                        set oKeys = in_objFCurveEditor.SelectedKeys( oCurve )
                        if ( oKeys.Count = 0 ) then
                                logmessage "There are no keys selected on this fcurve"
                        else
                                strInfo = ""
                                for each oKey in oKeys
                                        strInfo = strInfo & "(" & Round( oKey.Time, 3 ) & ", " & Round( oKey.Value, 3 ) & ") "
                                next
                                LogMessage "The following keys are selected on this FCurve: " & strInfo
                        end if                  
                next
                'The user may have selected a region in the fcurve editor.  This information is available like this:
                logmessage "-------------------------------------"
                dim Start, endFrame, Min, Max
                Start = in_objFCurveEditor.EditorAttribute( siRegionStartFrame )
                endFrame = in_objFCurveEditor.EditorAttribute( siRegionEndFrame )
                Min = in_objFCurveEditor.EditorAttribute( siRegionMin )
                Max = in_objFCurveEditor.EditorAttribute( siRegionMax )
                if ( Start <> endFrame ) then
                        logmessage "User has selected time region from frame " &_ 
                                                round( Start, 2 ) & " to " & round( endFrame, 2 )
                else
                        logmessage "No time region is selected"
                end if 
                if ( Min <> Max ) then
                        logmessage "User has selected key value range from " &_ 
                                                round( Min, 2 ) & " to " & round( Max, 2 )
                else
                        logmessage "No Value region is selected"
                end if 
        end if
end sub
'This second demo is action oriented - it changes the state of the FCurves that are selected.
'
'In this case we take the selected keys and set their values to the average.
sub OnAvgSelectedPoints( in_objFCurveEditor )
        LogMessage "AvgSelectedPoints called"
        'Example of some simple error handling
        if ( typename( in_objFCurveEditor ) <> "FCurveEditor" ) then
                LogMessage "Invalid argument to command - Should be FCurveEditor object instead we got a " _ 
                                        & typename( in_objFCurveEditor ), siError
                exit sub
        end if
        dim bDidSomething
        bDidSomething = false
        dim oCurves, oCurve
        set oCurves = in_objFCurveEditor.SelectedFCurves
        for each oCurve in oCurves
                dim oKeys, oKey, cntKeys
                set oKeys = in_objFCurveEditor.SelectedKeys( oCurve )
                cntKeys = oKeys.Count
                if ( cntKeys > 1 ) then
                        dim sumValues, avgValue
                        sumValues = 0
                        for each oKey in oKeys
                                sumValues = sumValues + oKey.Value
                        next
                        avgValue = sumValues / cntKeys
                        for each oKey in oKeys
                                oKey.Value = avgValue
                        next
                        bDidSomething = true
                end if 
        next
        if ( not bDidSomething ) then
                LogMessage "Please select two or more keys on an fcurve to average"
        end if
end sub

See Also

Command FCurve