First commit of mocap_tools.py, contains functions for Fcurve simplification and loop detection of anims

This commit is contained in:
Benjy Cook 2011-05-25 10:42:57 +00:00
parent 435229e3b3
commit 655fcfbcc0

@ -0,0 +1,451 @@
from math import hypot, sqrt, isfinite
import bpy
import time
from mathutils import Vector
#Vector utility functions
class NdVector:
vec = []
def __init__(self,vec):
self.vec = vec[:]
def __len__(self):
return len(self.vec)
def __mul__(self,otherMember):
if type(otherMember)==type(1) or type(otherMember)==type(1.0):
return NdVector([otherMember*x for x in self.vec])
else:
a = self.vec
b = otherMember.vec
n = len(self)
return sum([a[i]*b[i] for i in range(n)])
def __sub__(self,otherVec):
a = self.vec
b = otherVec.vec
n = len(self)
return NdVector([a[i]-b[i] for i in range(n)])
def __add__(self,otherVec):
a = self.vec
b = otherVec.vec
n = len(self)
return NdVector([a[i]+b[i] for i in range(n)])
def vecLength(self):
return sqrt(self * self)
def vecLengthSq(self):
return (self * self)
def __getitem__(self,i):
return self.vec[i]
length = property(vecLength)
lengthSq = property(vecLengthSq)
class dataPoint:
index = 0
co = Vector((0,0,0,0)) # x,y1,y2,y3 coordinate of original point
u = 0 #position according to parametric view of original data, [0,1] range
temp = 0 #use this for anything
def __init__(self,index,co,u=0):
self.index = index
self.co = co
self.u = u
def autoloop_anim():
context = bpy.context
obj = context.active_object
fcurves = [x for x in obj.animation_data.action.fcurves if x.select]
data = []
end = len(fcurves[0].keyframe_points)
for i in range(1,end):
vec = []
for fcurve in fcurves:
vec.append(fcurve.evaluate(i))
data.append(NdVector(vec))
def comp(a,b):
return a*b
N = len(data)
Rxy = [0.0] * N
for i in range(N):
for j in range(i,min(i+N,N)):
Rxy[i]+=comp(data[j],data[j-i])
for j in range(i):
Rxy[i]+=comp(data[j],data[j-i+N])
Rxy[i]/=float(N)
def bestLocalMaximum(Rxy):
Rxyd = [Rxy[i]-Rxy[i-1] for i in range(1,len(Rxy))]
maxs = []
for i in range(1,len(Rxyd)-1):
a = Rxyd[i-1]
b = Rxyd[i]
print(a,b)
if (a>=0 and b<0) or (a<0 and b>=0): #sign change (zerocrossing) at point i, denoting max point (only)
maxs.append((i,max(Rxy[i],Rxy[i-1])))
return max(maxs,key=lambda x: x[1])[0]
flm = bestLocalMaximum(Rxy[0:int(len(Rxy))])
diff = []
for i in range(len(data)-flm):
diff.append((data[i]-data[i+flm]).lengthSq)
def lowerErrorSlice(diff,e):
bestSlice = (0,100000) #index, error at index
for i in range(e,len(diff)-e):
errorSlice = sum(diff[i-e:i+e+1])
if errorSlice<bestSlice[1]:
bestSlice = (i,errorSlice)
return bestSlice[0]
margin = 2
s = lowerErrorSlice(diff,margin)
print(flm,s)
loop = data[s:s+flm+margin]
#find *all* loops, s:s+flm, s+flm:s+2flm, etc... and interpolate between all
# to find "the perfect loop". Maybe before finding s? interp(i,i+flm,i+2flm)....
for i in range(1,margin+1):
w1 = sqrt(float(i)/margin)
loop[-i] = (loop[-i]*w1)+(loop[0]*(1-w1))
for curve in fcurves:
pts = curve.keyframe_points
for i in range(len(pts)-1,-1,-1):
pts.remove(pts[i])
for c,curve in enumerate(fcurves):
pts = curve.keyframe_points
for i in range(len(loop)):
pts.insert(i+1,loop[i][c])
context.scene.frame_end = flm+1
def simplifyCurves(curveGroup, error, reparaError, maxIterations, group_mode):
def unitTangent(v,data_pts):
tang = Vector((0,0,0,0)) #
if v!=0:
#If it's not the first point, we can calculate a leftside tangent
tang+= data_pts[v].co-data_pts[v-1].co
if v!=len(data_pts)-1:
#If it's not the last point, we can calculate a rightside tangent
tang+= data_pts[v+1].co-data_pts[v].co
tang.normalize()
return tang
#assign parametric u value for each point in original data
def chordLength(data_pts,s,e):
totalLength = 0
for pt in data_pts[s:e+1]:
i = pt.index
if i==s:
chordLength = 0
else:
chordLength = (data_pts[i].co-data_pts[i-1].co).length
totalLength+= chordLength
pt.temp = totalLength
for pt in data_pts[s:e+1]:
if totalLength==0:
print(s,e)
pt.u = (pt.temp/totalLength)
# get binomial coefficient, this function/table is only called with args (3,0),(3,1),(3,2),(3,3),(2,0),(2,1),(2,2)!
binomDict = {(3,0): 1, (3,1): 3, (3,2): 3, (3,3): 1, (2,0): 1, (2,1): 2, (2,2): 1}
#value at pt t of a single bernstein Polynomial
def bernsteinPoly(n,i,t):
binomCoeff = binomDict[(n,i)]
return binomCoeff * pow(t,i) * pow(1-t,n-i)
# fit a single cubic to data points in range [s(tart),e(nd)].
def fitSingleCubic(data_pts,s,e):
# A - matrix used for calculating C matrices for fitting
def A(i,j,s,e,t1,t2):
if j==1:
t = t1
if j==2:
t = t2
u = data_pts[i].u
return t * bernsteinPoly(3,j,u)
# X component, used for calculating X matrices for fitting
def xComponent(i,s,e):
di = data_pts[i].co
u = data_pts[i].u
v0 = data_pts[s].co
v3 = data_pts[e].co
a = v0*bernsteinPoly(3,0,u)
b = v0*bernsteinPoly(3,1,u) #
c = v3*bernsteinPoly(3,2,u)
d = v3*bernsteinPoly(3,3,u)
return (di -(a+b+c+d))
t1 = unitTangent(s,data_pts)
t2 = unitTangent(e,data_pts)
c11 = sum([A(i,1,s,e,t1,t2)*A(i,1,s,e,t1,t2) for i in range(s,e+1)])
c12 = sum([A(i,1,s,e,t1,t2)*A(i,2,s,e,t1,t2) for i in range(s,e+1)])
c21 = c12
c22 = sum([A(i,2,s,e,t1,t2)*A(i,2,s,e,t1,t2) for i in range(s,e+1)])
x1 = sum([xComponent(i,s,e)*A(i,1,s,e,t1,t2) for i in range(s,e+1)])
x2 = sum([xComponent(i,s,e)*A(i,2,s,e,t1,t2) for i in range(s,e+1)])
# calculate Determinate of the 3 matrices
det_cc = c11 * c22 - c21 * c12
det_cx = c11 * x2 - c12 * x1
det_xc = x1 * c22 - x2 * c12
# if matrix is not homogenous, fudge the data a bit
if det_cc == 0:
det_cc=0.01
# alpha's are the correct offset for bezier handles
alpha0 = det_xc / det_cc #offset from right (first) point
alpha1 = det_cx / det_cc #offset from left (last) point
sRightHandle = data_pts[s].co.copy()
sTangent = t1*abs(alpha0)
sRightHandle+= sTangent #position of first pt's handle
eLeftHandle = data_pts[e].co.copy()
eTangent = t2*abs(alpha1)
eLeftHandle+= eTangent #position of last pt's handle.
#return a 4 member tuple representing the bezier
return (data_pts[s].co,
sRightHandle,
eLeftHandle,
data_pts[e].co)
# convert 2 given data points into a cubic bezier.
# handles are offset along the tangent at a 3rd of the length between the points.
def fitSingleCubic2Pts(data_pts,s,e):
alpha0 = alpha1 = (data_pts[s].co-data_pts[e].co).length / 3
sRightHandle = data_pts[s].co.copy()
sTangent = unitTangent(s,data_pts)*abs(alpha0)
sRightHandle+= sTangent #position of first pt's handle
eLeftHandle = data_pts[e].co.copy()
eTangent = unitTangent(e,data_pts)*abs(alpha1)
eLeftHandle+= eTangent #position of last pt's handle.
#return a 4 member tuple representing the bezier
return (data_pts[s].co,
sRightHandle,
eLeftHandle,
data_pts[e].co)
#evaluate bezier, represented by a 4 member tuple (pts) at point t.
def bezierEval(pts,t):
sumVec = Vector((0,0,0,0))
for i in range(4):
sumVec+=pts[i]*bernsteinPoly(3,i,t)
return sumVec
#calculate the highest error between bezier and original data
#returns the distance and the index of the point where max error occurs.
def maxErrorAmount(data_pts,bez,s,e):
maxError = 0
maxErrorPt = s
if e-s<3: return 0, None
for pt in data_pts[s:e+1]:
bezVal = bezierEval(bez,pt.u)
tmpError = (pt.co-bezVal).length/pt.co.length
if tmpError >= maxError:
maxError = tmpError
maxErrorPt = pt.index
return maxError,maxErrorPt
#calculated bezier derivative at point t.
#That is, tangent of point t.
def getBezDerivative(bez,t):
n = len(bez)-1
sumVec = Vector((0,0,0,0))
for i in range(n-1):
sumVec+=bernsteinPoly(n-1,i,t)*(bez[i+1]-bez[i])
return sumVec
#use Newton-Raphson to find a better paramterization of datapoints,
#one that minimizes the distance (or error) between bezier and original data.
def newtonRaphson(data_pts,s,e,bez):
for pt in data_pts[s:e+1]:
if pt.index==s:
pt.u=0
elif pt.index==e:
pt.u=1
else:
u = pt.u
qu = bezierEval(bez,pt.u)
qud = getBezDerivative(bez,u)
#we wish to minimize f(u), the squared distance between curve and data
fu = (qu-pt.co).length**2
fud = (2*(qu.x-pt.co.x)*(qud.x))-(2*(qu.y-pt.co.y)*(qud.y))
if fud==0:
fu = 0
fud = 1
pt.u=pt.u-(fu/fud)
def createDataPts(curveGroup, group_mode):
data_pts = []
if group_mode:
for i in range(len(curveGroup[0].keyframe_points)):
x = curveGroup[0].keyframe_points[i].co.x
y1 = curveGroup[0].keyframe_points[i].co.y
y2 = curveGroup[1].keyframe_points[i].co.y
y3 = curveGroup[2].keyframe_points[i].co.y
data_pts.append(dataPoint(i,Vector((x,y1,y2,y3))))
else:
for i in range(len(curveGroup.keyframe_points)):
x = curveGroup.keyframe_points[i].co.x
y1 = curveGroup.keyframe_points[i].co.y
y2 = 0
y3 = 0
data_pts.append(dataPoint(i,Vector((x,y1,y2,y3))))
return data_pts
def fitCubic(data_pts,s,e):
if e-s<3: # if there are less than 3 points, fit a single basic bezier
bez = fitSingleCubic2Pts(data_pts,s,e)
else:
#if there are more, parameterize the points and fit a single cubic bezier
chordLength(data_pts,s,e)
bez = fitSingleCubic(data_pts,s,e)
#calculate max error and point where it occurs
maxError,maxErrorPt = maxErrorAmount(data_pts,bez,s,e)
#if error is small enough, reparameterization might be enough
if maxError<reparaError and maxError>error:
for i in range(maxIterations):
newtonRaphson(data_pts,s,e,bez)
if e-s<3:
bez = fitSingleCubic2Pts(data_pts,s,e)
else:
bez = fitSingleCubic(data_pts,s,e)
#recalculate max error and point where it occurs
maxError,maxErrorPt = maxErrorAmount(data_pts,bez,s,e)
#repara wasn't enough, we need 2 beziers for this range.
#Split the bezier at point of maximum error
if maxError>error:
fitCubic(data_pts,s,maxErrorPt)
fitCubic(data_pts,maxErrorPt,e)
else:
#error is small enough, return the beziers.
beziers.append(bez)
return
def createNewCurves(curveGroup,beziers,group_mode):
#remove all existing data points
if group_mode:
for fcurve in curveGroup:
for i in range(len(fcurve.keyframe_points)-1,0,-1):
fcurve.keyframe_points.remove(fcurve.keyframe_points[i])
else:
fcurve = curveGroup
for i in range(len(fcurve.keyframe_points)-1,0,-1):
fcurve.keyframe_points.remove(fcurve.keyframe_points[i])
#insert the calculated beziers to blender data.\
if group_mode:
for fullbez in beziers:
for i,fcurve in enumerate(curveGroup):
bez = [Vector((vec[0],vec[i+1])) for vec in fullbez]
newKey = fcurve.keyframe_points.insert(frame=bez[0].x,value=bez[0].y)
newKey.handle_right = (bez[1].x,bez[1].y)
newKey = fcurve.keyframe_points.insert(frame=bez[3].x,value=bez[3].y)
newKey.handle_left= (bez[2].x,bez[2].y)
else:
for bez in beziers:
for vec in bez:
vec.resize_2d()
newKey = fcurve.keyframe_points.insert(frame=bez[0].x,value=bez[0].y)
newKey.handle_right = (bez[1].x,bez[1].y)
newKey = fcurve.keyframe_points.insert(frame=bez[3].x,value=bez[3].y)
newKey.handle_left= (bez[2].x,bez[2].y)
#indices are detached from data point's frame (x) value and stored in the dataPoint object, represent a range
data_pts = createDataPts(curveGroup,group_mode)
s = 0 #start
e = len(data_pts)-1 #end
beziers = []
#begin the recursive fitting algorithm.
fitCubic(data_pts,s,e)
#remove old Fcurves and insert the new ones
createNewCurves(curveGroup,beziers,group_mode)
#Main function of simplification
#sel_opt: either "sel" or "all" for which curves to effect
#error: maximum error allowed, in fraction (20% = 0.0020), i.e. divide by 10000 from percentage wanted.
#group_mode: boolean, to analyze each curve seperately or in groups, where group is all curves that effect the same property (e.g. a bone's x,y,z rotation)
def fcurves_simplify(sel_opt="all", error=0.002, group_mode=True):
# main vars
context = bpy.context
obj = context.active_object
fcurves = obj.animation_data.action.fcurves
if sel_opt=="sel":
sel_fcurves = [fcurve for fcurve in fcurves if fcurve.select]
else:
sel_fcurves = fcurves[:]
#Error threshold for Newton Raphson reparamatizing
reparaError = error*32
maxIterations = 16
if group_mode:
fcurveDict = {}
#this loop sorts all the fcurves into groups of 3, based on their RNA Data path, which corresponds to which property they effect
for curve in sel_fcurves:
if curve.data_path in fcurveDict: #if this bone has been added, append the curve to its list
fcurveDict[curve.data_path].append(curve)
else:
fcurveDict[curve.data_path] = [curve] #new bone, add a new dict value with this first curve
fcurveGroups = fcurveDict.values()
else:
fcurveGroups = sel_fcurves
if error>0.00000:
#simplify every selected curve.
totalt = 0
for i,fcurveGroup in enumerate(fcurveGroups):
print("Processing curve "+str(i+1)+"/"+str(len(fcurveGroups)))
t = time.clock()
simplifyCurves(fcurveGroup,error,reparaError,maxIterations,group_mode)
t = time.clock() - t
print(str(t)[:5]+" seconds to process last curve")
totalt+=t
print(str(totalt)[:5]+" seconds, total time elapsed")
return