WIP: completely messed up. trying to fix surface normal directions

This commit is contained in:
Michael Krayer 2021-08-13 22:05:35 +02:00
parent 6e3564c3c1
commit d95453ad45
1 changed files with 213 additions and 43 deletions

256
field.py
View File

@ -659,7 +659,7 @@ class Features3d:
# Assign basic properties to class variables
self.origin = np.array(origin,dtype=np.float)
self.spacing = np.array(spacing,dtype=np.float)
self.dimensions = input.shape
self.dimensions = np.array(input.shape,dtype=np.int)
self.periodicity = tuple(bool(x) for x in periodicity)
# If regions are supposed to be inverted, i.e. the interior consists of values
# smaller than the threshold instead of larger, change the sign of the array.
@ -712,8 +712,14 @@ class Features3d:
# Compute full contour: ensure we only have triangles to efficiently extract points
# later on.
if report: print('[Features3d.triangulate] computing isocontour using {}...'.format(contour_method))
contour = datavtk.contour([self._threshold],method=contour_method,compute_scalars=False)
contour = datavtk.contour([self._threshold],method=contour_method,compute_scalars=False,compute_gradients=True)
assert contour.is_all_triangles(), "Contouring produced non-triangle cells."
# print(contour.point_arrays['Gradients'].shape)
# print('gradient',time()-t)
# print(np.sum(gn>0),'of',len(gn))
# Compute the connectivity of the triangulated surface: first we run an ordinary
# connectivity filter neglecting periodic wrapping.
if report: print('[Features3d.triangulate] computing connectivity...')
@ -769,6 +775,8 @@ class Features3d:
# point of each cell determines the value for this cell.
if report: print('[Features3d.triangulate] identifying cell based labels...')
cell_labels = point_labels[contour.faces.reshape(contour.n_faces,4)[:,1]]
cell_gradient = contour.point_arrays['Gradients'][contour.faces.reshape(contour.n_faces,4)[:,1]]
print(cell_gradient.shape)
# We are done with VTK for now. Since we are only dealing with triangles, let us
# store them in a structure which is quicker to access and already sorted based
# on labels.
@ -780,8 +788,7 @@ class Features3d:
ind = np.argsort(cell_labels)
self._offset = np.zeros((self._nfeatures+1,),dtype=np.int64)
self._offset[1:] = np.cumsum(np.bincount(cell_labels))
self._vertices = np.ascontiguousarray(
contour.points[contour.faces.reshape(contour.n_faces,4)[ind,1:]])
self._vertices = contour.points[contour.faces.reshape(contour.n_faces,4)[ind,1:]]
# Compute the volume and area per cell. For the volume computation, an arbitrary component
# of the normal has to be chosen which defaults to the z-component and is set by
# 'cellvol_normal_component'.
@ -791,8 +798,39 @@ class Features3d:
C = self._vertices[:,2,:]
cn = np.cross(B-A,C-A)
cc = (A+B+C)/3
# print(contour.point_arrays['Gradients'][contour.faces.reshape(contour.n_faces,4)[:,1:]].shape)
cg = (contour.point_arrays['Gradients'][contour.faces.reshape(contour.n_faces,4)[:,1:]][:,0,:]+
contour.point_arrays['Gradients'][contour.faces.reshape(contour.n_faces,4)[:,1:]][:,1,:]+
contour.point_arrays['Gradients'][contour.faces.reshape(contour.n_faces,4)[:,1:]][:,2,:])/3
ng = (cg*cn).sum(axis=-1)
print('interpolated:')
print(cg)
print('component 0:')
print(contour.point_arrays['Gradients'][contour.faces.reshape(contour.n_faces,4)[:,1:]][:,0,:])
print('projection')
print(sum(ng>0),len(ng))
# self.cg = cg
# self.cc = cc
self.cg = contour.point_arrays['Gradients']
self.cc = contour.points
# .sum(axis=1))/3)*cn).sum(axis=-1)
self._cell_areas = 0.5*np.sqrt(np.square(cn).sum(axis=1))
self._cell_volumes = 0.5*cn[:,cellvol_normal_component]*cc[:,cellvol_normal_component]
# # Compute gradient of field at cell center to get correct cell normal direction
# t = time()
# cn = cn/np.sqrt(np.square(cn).sum())
# ccpix = ((cc-self.origin)/self.spacing).transpose()
# ccnpix = (((cc+1e-4*cn)-self.origin)/self.spacing).transpose()
# val_cc = ndimage.map_coordinates(self._input,ccpix,order=1,prefilter=False)
# val_ccn = ndimage.map_coordinates(self._input,ccnpix,order=1,prefilter=False)
# gn = (val_ccn-val_cc)
# print('gradient',time()-t)
# print(cg)
# print(np.sum(cg>0),'of',cg.shape)
# stop
return
@property
@ -821,19 +859,17 @@ class Features3d:
self.discard_features(np.flatnonzero(np.abs(self.volumes())<threshold),report=report)
return
def discard_features(self,labels,clean_points=False,report=False):
def discard_features(self,features,report=False):
'''Removes features from triangulated data.'''
from collections.abc import Iterable
from time import time
if not isinstance(labels,Iterable): labels = [labels]
features = self.list_of_features(features)
# Get index ranges which are to be deleted and also create an array
# which determines the size of the block to be deleted
idx = []
gapsize = np.zeros((self.nfeatures,),dtype=np.int)
for label in labels:
rng_ = np.arange(self._offset[label],self._offset[label+1])
gapsize = np.zeros((self._nfeatures,),dtype=np.int)
for feature in features:
rng_ = np.arange(self._offset[feature],self._offset[feature+1])
idx.append(rng_)
gapsize[label] = len(rng_)
gapsize[feature] = len(rng_)
idx = np.concatenate(idx,axis=0)
# Save former number of faces for report
ncells = self._vertices.shape[0]
@ -843,11 +879,12 @@ class Features3d:
self._cell_volumes = np.delete(self._cell_volumes,idx,axis=0)
# Correct offset
self._offset[1:] = self._offset[1:]-np.cumsum(gapsize)
self._offset = self._offset[:-len(labels)]
self._offset = np.delete(self._offset,features,axis=0)
self._nfeatures = self._offset.shape[0]-1
if report:
print('[Features3d.discard_features]',end=' ')
print('discarded {:} features with {:} faces.'.format(
len(labels),ncells-self._vertices.shape[0]))
len(features),ncells-self._vertices.shape[0]))
return
def area(self,feature):
@ -902,9 +939,9 @@ class Features3d:
self._kdradius = radius
if report:
print('[Features3d.build_kdtree]',end=' ')
print('KD-Tree built for axis {}.'.format(axis))
print('KD-Tree built for axis {}.'.format(kdaxis))
def inside_feature(self,coords):
def inside_feature(self,coords,report=True):
'''Find nearest triangle from point R in direction ±dR and its orientation w.r.t dR.
The algorithm determines the closest intersection of a ray cast from the origin of the
point in the specified direction (with positiv and negative sign). The ray is supposed to
@ -934,29 +971,133 @@ class Features3d:
cand = self._kdtree.query_ball_point(coords[:,query_axis],self._kdradius)
N = coords.shape[0]
if coords.shape[0]>12279:
print('Point coordinates:',coords[12279,:])
Ncoord = coords.shape[0]
raydir = np.zeros((3,),dtype=self._vertices.dtype)
raydir[self._kdaxis] = 1.0
in_feat = np.empty((N,),dtype=np.int)
for ii in range(N):
hit_idx,t,N = Features3d.ray_triangle_intersection(coords[ii],raydir,
in_feat = np.empty((Ncoord,),dtype=np.int)
is_hit = np.empty((Ncoord,),dtype=np.int)
hit_dir_ = np.empty((Ncoord,),dtype=np.int)
face_ = np.empty((Ncoord,),dtype=np.int)
for ii in range(Ncoord):
hit_idx,t,hit_dir = Features3d.ray_triangle_intersection(coords[ii],raydir,
self._vertices[cand[ii],0,:],
self._vertices[cand[ii],1,:],
self._vertices[cand[ii],2,:])
# if ii==12279: print('DEBUG',hit_idx,t,N)
if hit_idx is None:
in_feat[ii] = -1
is_hit[ii] = -1
hit_dir_[ii]= 0
face_[ii] = -1
else:
idx = np.argmin(np.abs(t))
if t[idx]*(N[idx,:]*raydir).sum(axis=-1)>0:
in_feat[ii] = self.feature_by_cell(cand[ii][idx])
# print(cand[ii][hit_idx[idx]])
if ii==12279:
# print(cand[ii][idx],N[idx,:],N[idx,:]/np.sqrt(np.square(N[idx,:]).sum()),(N[idx,:]*raydir).sum(axis=-1),t[idx]*(N[idx,:]*raydir).sum(axis=-1))
print(t[idx],hit_dir[idx],raydir)
print(self._vertices[cand[ii][hit_idx[idx]],:,:])
hit_dir_[ii]= hit_dir[idx]
face_[ii] = cand[ii][hit_idx[idx]]
if hit_dir[idx]<0:
in_feat[ii] = self.feature_from_cellidx(cand[ii][hit_idx[idx]])
is_hit[ii] = 1
else:
in_feat[ii] = -1
return in_feat
is_hit[ii] = 0
if report:
print('[Features3d.inside_feature]',end=' ')
print('{} of {} points are located inside of features.'.format(sum(in_feat>=0),Ncoord))
return in_feat #,is_hit,hit_dir_,face_
def feature_by_cell(self,idx_cell):
def feature_from_cellidx(self,idx_cell):
'''Gets feature ID for a given cell.'''
return np.argmax(idx_cell>self._offset)
# This is an optimized solution for monotonically increasing arrays:
# as long as offset is smaller than the cell index, the boolean operation
# returns False. As soon as the first True is returned, i.e.
# as soon as idx_cell is equal or larger than offset, the argmax function
# short circuits and returns the index of the first occurence without
# checking any value afterwards.
return np.argmax(self._offset>=idx_cell)
def cellidx_from_feature(self,features,concat=True):
'''Returns indices of cells which belong to given features.'''
from collections.abc import Iterable
if features is None:
idx = None
elif not isinstance(features,Iterable):
idx = slice(self._offset[features],self._offset[features+1])
elif concat:
idx = []
for feature in features:
rng_ = np.arange(self._offset[feature],self._offset[feature+1])
idx.append(rng_)
idx = np.concatenate(idx,axis=0)
else:
idx = []
for feature in features:
rng_ = slice(self._offset[feature],self._offset[feature+1])
idx.append(rng_)
return idx
def ncells_from_feature(self,features):
'''Returns number of cells which belong to given features. Can be used
to construct new offsets.'''
features = self.list_of_features(features)
ncells = []
for feature in features:
ncells.append(self._offset[feature+1]-self._offset[feature])
return np.array(ncells)
def list_of_features(self,features):
'''Ensures that 'features' is a list.'''
from collections.abc import Iterable
if features is None:
return np.arange(0,self._nfeatures)
if not isinstance(features,Iterable):
return [features]
else:
return list(features)
# @staticmethod
# def ray_triangle_intersection(r0,dr,v0,v1,v2):
# '''Implements the MöllerTrumbore ray-triangle intersection algorithm. I modified the
# formulation of
# https://stackoverflow.com/questions/42740765/intersection-between-line-and-triangle-in-3d
# because it computes the cell normal on the way, which is needed to determine the
# direction of the hit, i.e. from the inside or outside.
# Input:
# R, dR: origin and direction of the ray as (3,) numpy arrays
# A,B,C: vertices of N triangles as (N,3) numpy arrays
# Returns:
# hit_idx: index of the input triangles which returned a hit. [(Nhit,) int]
# t: parameter to determine intersection point (x = R+t*dR) [(Nhit,) float]
# N: normal vector of triangles which were hit [(Nhit,3) float]
# All returned values are None if not hit occured.
# '''
# v0v1 = v1-v0
# v0v2 = v2-v0
# pvec = np.cross(dr,v0v2)
# det = (v0v1*pvec).sum(axis=-1) # det<0: from behind, det>0 from front ("culling")
# norm = 1e0 # we should normalize the unit vector?
# det[np.abs(det)<1e-6*norm] = np.nan # mask to avoid numpy runtime errors
# invDet = 1./det
# tvec = r0-v0
# qvec = np.cross(tvec,v0v1)
# u = (tvec*pvec).sum(axis=-1)*invDet
# v = (dr*qvec).sum(axis=-1)*invDet
# is_hit = np.logical_and(
# np.logical_and(
# np.logical_and(
# np.isfinite(det),u>=-1e-6),
# v>=1e-6),
# (u+v)-1.0<=1e-6)
# hit_idx = np.flatnonzero(is_hit)
# if len(hit_idx)==0: return (None,None,None)
# t = (v0v2[hit_idx,:]*qvec[hit_idx,:]).sum(axis=-1)*invDet[hit_idx];
# return hit_idx,t,np.sign(det[hit_idx])
@staticmethod
def ray_triangle_intersection(R,dR,A,B,C):
'''Implements the MöllerTrumbore ray-triangle intersection algorithm. I modified the
@ -988,46 +1129,75 @@ class Features3d:
is_hit = np.logical_and(
np.logical_and(
np.logical_and(
np.isfinite(det),u>=0.0),
v>=0.0),
(u+v)<=1.0)
np.isfinite(det),u>=-1e-6),
v>=-1e-6),
(u+v)-1.0<=1e-6)
hit_idx = np.flatnonzero(is_hit)
if len(hit_idx)==0: return (None,None,None)
# Intersection point is R+t*dR
t = (AO[hit_idx,:]*N[hit_idx,:]).sum(axis=-1)*invdet[hit_idx]
return hit_idx,t,N[hit_idx]
return hit_idx,t,np.sign(t)*np.sign(det[hit_idx])
def faces_points_representation(self,labels,reduce_points=False):
def faces_points_representation(self,features,reduce_points=False):
from collections.abc import Iterable
# Select relevant cells
if labels is None:
idx = None
else:
if not isinstance(labels,Iterable): labels = [labels]
idx = []
for label in labels:
rng_ = np.arange(self._offset[label],self._offset[label+1])
idx.append(rng_)
idx = np.concatenate(idx,axis=0)
idx = self.cellidx_from_feature(features)
if reduce_points:
points,faces_ = np.unique(self._vertices[idx,:,:].reshape(-1,3),return_inverse=True,axis=0)
ncells = faces_.shape[0]//3
faces = np.empty((ncells,4),dtype=np.int)
faces[:,0] = 3
faces[:,1:] = faces_.reshape(ncells,3)
print('reduced:',faces.shape)
else:
points = self._vertices[idx,:,:].reshape((-1,3))
ncells = points.shape[0]//3
faces = np.empty((ncells,4),dtype=np.int)
faces[:,0] = 3
faces[:,1:] = np.arange(0,3*ncells).reshape(ncells,3)
print('full:',faces.shape)
return faces,points
def to_vtk(self,labels,reduce_points=False):
def cmap_features(self,nfeatures,name='tab10'):
from matplotlib.colors import ListedColormap
if name=='tab10': # seaborn/matplotlib tab10
cmap = [(0.12156862745098039, 0.4666666666666667, 0.7058823529411765),
(1.0, 0.4980392156862745, 0.054901960784313725),
(0.17254901960784313, 0.6274509803921569, 0.17254901960784313),
(0.8392156862745098, 0.15294117647058825, 0.1568627450980392),
(0.5803921568627451, 0.403921568627451, 0.7411764705882353),
(0.5490196078431373, 0.33725490196078434, 0.29411764705882354),
(0.8901960784313725, 0.4666666666666667, 0.7607843137254902),
(0.4980392156862745, 0.4980392156862745, 0.4980392156862745),
(0.7372549019607844, 0.7411764705882353, 0.13333333333333333),
(0.09019607843137255, 0.7450980392156863, 0.8117647058823529)]
else:
raise NotImplementedError('Colormap not implemented.')
ncolor = len(cmap)
icolor = 0
output = np.empty((nfeatures,3))
for ii in range(nfeatures):
output[ii] = cmap[icolor]
icolor = (icolor+1)%ncolor
return ListedColormap(output)
def to_vtk(self,features,reduce_points=False,store_labels=False,remap_labels=False):
'''Returns a VTK/pyvista object for the isocontour of a single feature,
list of features, or the full isocontour (when None is passed).'''
import pyvista as pv
from collections.abc import Iterable
faces,points = self.faces_points_representation(labels,reduce_points=reduce_points)
return pv.PolyData(points,faces)
faces,points = self.faces_points_representation(features,reduce_points=reduce_points)
output = pv.PolyData(points,faces)
if store_labels:
output.cell_arrays['label'] = np.empty(faces.shape[0],dtype=np.int)
offset = 0
for ii,feature in enumerate(self.list_of_features(features)):
ncells = self.ncells_from_feature(feature)
if remap_labels:
output.cell_arrays['label'][offset:offset+ncells] = ii
else:
output.cell_arrays['label'][offset:offset+ncells] = feature
offset += ncells
return output
class BinaryFieldNd:
def __init__(self,input,periodicity,connect_diagonals=False,deep=False,has_ghost=False):