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- # ***** BEGIN LICENSE BLOCK *****
- # Version: MPL 1.1/GPL 2.0/LGPL 2.1
- #
- # The contents of this file are subject to the Mozilla Public License Version
- # 1.1 (the "License"); you may not use this file except in compliance with
- # the License. You may obtain a copy of the License at
- # http://www.mozilla.org/MPL/
- #
- # Software distributed under the License is distributed on an "AS IS" basis,
- # WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- # for the specific language governing rights and limitations under the
- # License.
- #
- # The Original Code is the Python Computer Graphics Kit.
- #
- # The Initial Developer of the Original Code is Matthias Baas.
- # Portions created by the Initial Developer are Copyright (C) 2004
- # the Initial Developer. All Rights Reserved.
- #
- # Contributor(s):
- #
- # Alternatively, the contents of this file may be used under the terms of
- # either the GNU General Public License Version 2 or later (the "GPL"), or
- # the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- # in which case the provisions of the GPL or the LGPL are applicable instead
- # of those above. If you wish to allow use of your version of this file only
- # under the terms of either the GPL or the LGPL, and not to allow others to
- # use your version of this file under the terms of the MPL, indicate your
- # decision by deleting the provisions above and replace them with the notice
- # and other provisions required by the GPL or the LGPL. If you do not delete
- # the provisions above, a recipient may use your version of this file under
- # the terms of any one of the MPL, the GPL or the LGPL.
- #
- # ***** END LICENSE BLOCK *****
- # $Id: motionpath.py,v 1.2 2006/01/27 07:51:02 mbaas Exp $
-
- from cgkit.component import Component
- from cgkit.slots import *
- from math import *
-
- # MotionPath
- class MotionPath(Component):
- """Motion path.
- """
-
- def __init__(self,
- name = "MotionPath",
- curve = None,
- begintime = 0.0,
- endtime = 1.0,
- loop = False,
- follow = False,
- bank = False,
- bankamplitude = 0.1,
- auto_insert = True):
- """Constructor.
- """
- Component.__init__(self, name=name, auto_insert=auto_insert)
-
- self.curve = curve
-
- self.begintime = begintime
- self.endtime = endtime
- self.loop = loop
- self.follow = follow
- self.bank = bank
- self.bankamplitude = bankamplitude
-
- self.transform_slot = ProceduralMat4Slot(self.computeTransform)
- self.time_slot = DoubleSlot()
- self.time_slot.addDependent(self.transform_slot)
- self.addSlot("transform", self.transform_slot)
- self.addSlot("time", self.time_slot)
-
- # computeTransform
- def computeTransform(self):
- """Procedural for the transform slot.
- """
-
- # Determine the native curve parameter t...
- time = self.time_slot.getValue()
- len = self.curve.length()
- s = (time-self.begintime)/(self.endtime-self.begintime)
- if self.loop:
- s %= 1.0
- s *= len
- if s<0:
- s = 0.0
- if s>len:
- s = len
- t = self.arcLenToCurveParam(s)
-
- # Evaluate the curve
- p, dp, d2p = self.curve.evalFrame(t)
-
- up = vec3(0,0,1)
- if self.follow:
- try:
- T = mat4().lookAt(p, p+dp, up)
- except:
- T = mat4().translation(p)
- else:
- T = mat4().translation(p)
-
- if self.bank:
- dp = dp.normalize()
-
- dt = 0.001
- dp_prev = self.curve.deriv(t-dt).normalize()
- d2p = (dp-dp_prev)/dt
- # Make the 2nd derivative orthogonal to the tangent...
- len = d2p.length()
- u = d2p.cross(dp)
- d2p = dp.cross(u)
- d2p = len*d2p.normalize()
- if (dp.cross(up)*d2p<0):
- len = -len
- T = T*mat4().rotation(self.bankamplitude*len, vec3(0,0,1))
- return T
-
- # arcLenToCurveParam
- def arcLenToCurveParam(self, s, eps=0.0001, maxiter=100):
- """Determine the native curve parameter for a given arc length.
- """
- tmin, tmax = self.curve.paraminterval
- totallen = self.curve.arcLen(tmax)
- # Initial "guess"...
- t = tmin+(s/totallen)*(tmax-tmin)
-
- while maxiter>0:
- F = self.curve.arcLen(t)-s
- if abs(F)<=eps:
- return t
-
- dF = self.curve.deriv(t).length()
- if abs(dF)<1E-12:
- # TODO: do something
- print "MotionPath: ************ dF==0 !!!"
- dF = 1
- t -= F/dF
- maxiter -= 1
-
- print "MotionPath: Maximum number of iterations reached (s=%f)"%s
- return t
-
-
-