Sets or returns the left tangent X (in frames) of the fcurve key
relative to the FCurveKey.Time
value as a Double.
The left tan x value may be a negative value between a distance
which is one third the distance between 2 consecutive key and 0;
this guarantees that the curve is valid.
The left tangent of the first key and the right tangent of the last
key cannot be changed. If you try to set the tangent for one of
these the property does nothing and returns S_FALSE in C++.
Tangent values only apply to standard function curves (where
FCurve.Type = siStandardFCurve), the
tangent value 0 is returned for all other function curve types
defined by siFCurveType.
/* This example illustrates how to create an fcurve and set the tangents on a specific key */ // Create new scene NewScene( "", false ); // Create a null var nullobj = Application.ActiveSceneRoot.AddNull(); // Get the posx parameter from the null var posx = nullobj.posx; // Create an fcurve on posx var fc = posx.AddFCurve2(); // Define some keys (3 key-value pairs) var keyvalues = new Array( 0,0, 50,25, 100,50 ); fc.SetKeys( keyvalues ); // Get the 1st, 2nd & 3rd FCurveKey objects var key0 = fc.Keys(0); var key1 = fc.Keys(1); var key2 = fc.Keys(2); // Make the key non-G1 continuous so it can have different left and right values key1.Constraint( siG1ContinuousConstraint ) = false; key1.LeftTanX = 0; key1.LeftTanY = Math.abs( key1.Value - key0.Value ); key1.RightTanX = key2.Time - key1.Time; key1.RightTanY = 0; PrintKeys( fc ); // Convenience function to print the FCurveKeys function PrintKeys( in_fcrv ) { for ( var i=0; i<in_fcrv.Keys.Count; i++ ) { var fckey = in_fcrv.Keys(i); var str = "key : " + fckey.Index; str += "\n\ttime : " + fckey.Time; str += "\n\tvalue : " + fckey.Value; str += "\n\ttangents : " + fckey.LeftTanX + "," + fckey.LeftTanY + "," + fckey.RightTanX + "," + fckey.RightTanY; str += "\n\tconstraints : " + GetConstraintType( fckey ); Application.LogMessage( str ); } } // Convenience function to get the user-friendly string describing the contraint type function GetConstraintType( in_fcrvkey ) { var ConstraintTypes = new Array ( new Array (siParameterConstraint, "LockParameter"), new Array (siLeftRightValuesConstraint, "LeftRightParameter"), new Array (siG1ContinuousConstraint, "G1Continuous"), new Array (siLeftRightTangentDirectionConstraint, "LeftRightTangentDirection"), new Array (siLeftRightTangentLengthConstraint, "LeftRightTangentLength"), new Array (siLockConstraint, "LockAll"), new Array (siHorizontalTangentConstraint, "HorizontalTangent"), new Array (siExtremumHorizontalTangentConstraint, "ExtremumHorizontalTangent"), new Array (siAdjustedTangentConstraint, "AdjustedTangent"), new Array (siZeroLengthTangentConstraint, "ZeroLengthTangent"), new Array (siSameLengthTangentConstraint, "SameLengthTangent"), new Array (siNeighborTangentConstraint, "NeighborTangent"), new Array (siMirrorTangentConstraint, "MirrorTangent"), new Array (siAutoPlateauTangentConstraint, "AutoPlateauTangent") ) var str = ""; for ( var i=0; i<ConstraintTypes.length; i++ ) { if ( in_fcrvkey.Constraint( ConstraintTypes[i][0] ) ) { str += ConstraintTypes[i][1] + " "; } } return str; } // Expected results: //INFO : key : 0 // time : 0 // value : 0 // tangents : -16.666666666666668,0,16.666666666666668,0 // constraints : G1Continuous //INFO : key : 1 // time : 50 // value : 25 // tangents : 0,25,50,0 // constraints : //INFO : key : 2 // time : 100 // value : 50 // tangents : -16.666666666666664,0,16.666666666666664,0 // constraints : G1Continuous |
' ' This example illustrates how to create an fcurve and set the tangents on a specific key ' ' Create new scene NewScene , false ' Create a null set nullobj = Application.ActiveSceneRoot.AddNull() ' Get the posx parameter from the null set posx = nullobj.posx ' Create an fcurve on posx set fc = posx.AddFCurve2() ' Define some keys (3 key-value pairs) keyvalues = array( 0,0, 50,25, 100,50 ) fc.SetKeys keyvalues ' Get the 1st, 2nd & 3rd FCurveKey objects set key0 = fc.Keys(0) set key1 = fc.Keys(1) set key2 = fc.Keys(2) ' Make the key non-G1 continuous so it can have different left and right values key1.Constraint( siG1ContinuousConstraint ) = false key1.LeftTanX = 0 key1.LeftTanY = Abs( key1.Value - key0.Value ) key1.RightTanX = key2.Time - key1.Time key1.RightTanY = 0 PrintKeys fc ' Convenience routine to print the FCurveKeys sub PrintKeys( in_fcrv ) for each fckey in in_fcrv.Keys str = "key : " & fckey.Index str = str & vbCrLf & vbTab & "time : " & fckey.Time str = str & vbCrLf & vbTab & "value : " & fckey.Value str = str & vbCrLf & vbTab & "tangents : " & fckey.LeftTanX & "," & fckey.LeftTanY & "," & fckey.RightTanX & "," & fckey.RightTanY str = str & vbCrLf & vbTab & "constraints : " & GetConstraintType( fckey ) Application.LogMessage str next end sub ' Convenience function to get the user-friendly string describing the contraint type function GetConstraintType( in_fcrvkey ) set ConstraintTypes = CreateObject( "Scripting.Dictionary" ) ConstraintTypes.Add siParameterConstraint, "LockParameter" ConstraintTypes.Add siLeftRightValuesConstraint, "LeftRightParameter" ConstraintTypes.Add siG1ContinuousConstraint, "G1Continuous" ConstraintTypes.Add siLeftRightTangentDirectionConstraint, "LeftRightTangentDirection" ConstraintTypes.Add siLeftRightTangentLengthConstraint, "LeftRightTangentLength" ConstraintTypes.Add siLockConstraint, "LockAll" ConstraintTypes.Add siHorizontalTangentConstraint, "HorizontalTangent" ConstraintTypes.Add siExtremumHorizontalTangentConstraint, "ExtremumHorizontalTangent" ConstraintTypes.Add siAdjustedTangentConstraint, "AdjustedTangent" ConstraintTypes.Add siZeroLengthTangentConstraint, "ZeroLengthTangent" ConstraintTypes.Add siSameLengthTangentConstraint, "SameLengthTangent" ConstraintTypes.Add siNeighborTangentConstraint, "NeighborTangent" ConstraintTypes.Add siMirrorTangentConstraint, "MirrorTangent" ConstraintTypes.Add siAutoPlateauTangentConstraint, "AutoPlateauTangent" str = "" for each k in ConstraintTypes.Keys if in_fcrvkey.Constraint( k ) then str = str & ConstraintTypes(k) & " " end if next GetConstraintType = str end function ' Expected results: 'INFO : key : 0 ' time : 0 ' value : 0 ' tangents : -16.6666666666667,0,16.6666666666667,0 ' constraints : G1Continuous 'INFO : key : 1 ' time : 50 ' value : 25 ' tangents : 0,25,50,0 ' constraints : 'INFO : key : 2 ' time : 100 ' value : 50 ' tangents : -16.6666666666667,0,16.6666666666667,0 ' constraints : G1Continuous |
# # This example illustrates how to create an fcurve and set the tangents on a specific key # from win32com.client import constants as c # Convenience function to get the user-friendly string describing the contraint type def GetConstraintType( in_fcrvkey ) : ConstraintTypes = { c.siParameterConstraint:"LockParameter", c.siLeftRightValuesConstraint:"LeftRightParameter", c.siG1ContinuousConstraint:"G1Continuous", c.siLeftRightTangentDirectionConstraint:"LeftRightTangentDirection", c.siLeftRightTangentLengthConstraint:"LeftRightTangentLength", c.siLockConstraint:"LockAll", c.siHorizontalTangentConstraint:"HorizontalTangent", c.siExtremumHorizontalTangentConstraint:"ExtremumHorizontalTangent", c.siAdjustedTangentConstraint:"AdjustedTangent", c.siZeroLengthTangentConstraint:"ZeroLengthTangent", c.siSameLengthTangentConstraint:"SameLengthTangent", c.siNeighborTangentConstraint:"NeighborTangent", c.siMirrorTangentConstraint:"MirrorTangent", c.siAutoPlateauTangentConstraint:"AutoPlateauTangent" } str = "" for k in ConstraintTypes.keys() : if ( in_fcrvkey.Constraint(k) ) : str += ConstraintTypes[k] + " " return str # Convenience function to print the FCurveKeys def PrintKeys( in_fcrv ) : for fckey in in_fcrv.Keys : str = "key : %d" % (fckey.Index) str = str + "\n\ttime : %d" % (fckey.Time) str = str + "\n\tvalue : %d" % (fckey.Value) str = str + "\n\ttangents : %d,%d,%d,%d" % (fckey.LeftTanX,fckey.LeftTanY,fckey.RightTanX,fckey.RightTanY) str = str + "\n\tconstraints : " + GetConstraintType( fckey ) Application.LogMessage( str ) return None # Create new scene Application.NewScene( "", 0 ) # Create a null nullobj = Application.ActiveSceneRoot.AddNull() # Get the posx parameter from the null posx = nullobj.posx # Create an fcurve on posx fc = posx.AddFCurve2() # Define some keys (3 key-value pairs) keyvalues = [ 0,0, 50,25, 100,50 ] fc.SetKeys( keyvalues ) # Get the 1st, 2nd & 3rd FCurveKey objects key0 = fc.Keys(0) key1 = fc.Keys(1) key2 = fc.Keys(2) # Make the key non-G1 continuous so it can have different left and right values # (Python can't use the Constraint property as-is, so use SetConstraint as an alias) key1.SetConstraint( c.siG1ContinuousConstraint, 0 ) key1.LeftTanX = 0 key1.LeftTanY = abs( key1.Value - key0.Value ) key1.RightTanX = key2.Time - key1.Time key1.RightTanY = 0 PrintKeys( fc ) # Expected results: # INFO : key : 0 # time : 0 # value : 0 # tangents : -16,0,16,0 # constraints : G1Continuous # INFO : key : 1 # time : 50 # value : 25 # tangents : 0,25,50,0 # constraints : # INFO : key : 2 # time : 100 # value : 50 # tangents : -16,0,16,0 # constraints : G1Continuous |