Die Verwendung der Maya-API ist sicherlich der beste Weg, um es zu tun, wie @ Scotttiedoo sagte, aber hier ist eine Funktion, die ich gemacht habe, wenn ich API nicht kannte und die Ihnen die gleichen Ergebnisse liefert.
from maya import cmds
def computeCrvLength(crv, startParam = None, endParam = None):
'''
Compute the length of a curve between the two given UParameters. If the both
UParameters arguments are set to None (default), will compute the length of
the whole curve.
Arguments:
- crv = string; an existing nurbCurve
- startParam = 0 <= float <= 1 or None; default = None; point parameter
value, if not None, will compute the points only between the startPt and
EndPt values.
- endParam = 0 <= float <= 1 or None; default = None; point parameter
value, if not None, will compute the points only between the startPt and
EndPt values.
Returns:
- The length of the curve between the given UParameters
- The length of the curve from its start to the startParam
- The length of the curve from its start to the endParam
'''
###### Exceptions
if cmds.objExists(crv) == False:
cmds.error ('The curve "%s" does\'nt exists.' % crv)
if cmds.filterExpand (crv, sm = 9) == None:
cmds.error ('The object "%s" is not a nurbCurve.' % crv)
if startParam != None:
if (0 <= startParam <= 1) == False:
cmds.error ('The start point parameter value must be between 0 and 1.')
if endParam != None:
if (0 <= endParam <= 1) == False:
cmds.error ('The end point parameter value must be between 0 and 1.')
if (startParam == None and endParam != None) or (startParam != None and endParam == None):
cmds.error ('The start and end points parameters must be both None or ' +
'both have values.')
if startParam != None and endParam != None:
if endParam < startParam:
cmds.error ('The end point parameter value cannot be less or ' +
'equal to start point parameter value.')
###### Function
if startParam == None and endParam == None:
crvLength = cmds.arclen (crv, ch = False)
distCrvToStartParam = 0
distCrvToEndParam = crvLength
else:
tmpArclenDim = cmds.arcLengthDimension (cmds.listRelatives(crv, s = True)[0]
+ '.u[0]')
cmds.setAttr (cmds.listRelatives(tmpArclenDim, p = True)[0] +
'.uParamValue', startParam)
distCrvToStartParam = cmds.getAttr (tmpArclenDim + '.al')
cmds.setAttr (cmds.listRelatives(tmpArclenDim, p = True)[0] +
'.uParamValue', endParam)
distCrvToEndParam = cmds.getAttr (tmpArclenDim + '.al')
cmds.delete (tmpArclenDim)
crvLength = (distCrvToEndParam - distCrvToStartParam)
return crvLength, distCrvToStartParam, distCrvToEndParam
Danke für die Antwort, so gibt es keine solche API in Maya2015? –
Mit Blick auf die Dokumente scheint es nicht so. Du könntest selbst einen schreiben, aber es ist etwas komplexer, wenn du nach Annäherungslängen von b-Splines forschst – scottiedoo