libigl_Martin/python/tutorial/505_MIQ.py

# Add the igl library to the modules search path
import sys, os
sys.path.insert(0, os.getcwd() + "/../")

import pyigl as igl
from math import pi

V = igl.eigen.MatrixXd()
F = igl.eigen.MatrixXi()

# Face barycenters
B = igl.eigen.MatrixXd()

# Scale for visualizing the fields
global_scale = 1
extend_arrows = False;

# Cross field
X1 = igl.eigen.MatrixXd()
X2 = igl.eigen.MatrixXd()

# Bisector field
BIS1 = igl.eigen.MatrixXd()
BIS2 = igl.eigen.MatrixXd()

# Combed bisector
BIS1_combed = igl.eigen.MatrixXd()
BIS2_combed = igl.eigen.MatrixXd()

# Per-corner, integer mismatches
MMatch = igl.eigen.MatrixXi()

# Field singularities
isSingularity = igl.eigen.MatrixXi()
singularityIndex = igl.eigen.MatrixXi()

# Per corner seams
Seams = igl.eigen.MatrixXi()

# Combed field
X1_combed = igl.eigen.MatrixXd()
X2_combed = igl.eigen.MatrixXd()

# Global parametrization (with seams)
UV_seams = igl.eigen.MatrixXd()
FUV_seams = igl.eigen.MatrixXi()

# Global parametrization
UV = igl.eigen.MatrixXd()
FUV = igl.eigen.MatrixXi()

# Texture
texture_R = igl.eigen.MatrixXuc()
texture_G = igl.eigen.MatrixXuc()
texture_B = igl.eigen.MatrixXuc()

# Create a texture that hides the integer translation in the parametrization
def line_texture():
    size = 128
    size2 = int(size/2)
    lineWidth = 3
    texture_R.setConstant(size, size, 255)

    for i in range(0,size):
        for j in range(size2-lineWidth,size2+lineWidth+1):
            texture_R[i,j] = 0

    for i in range(size2-lineWidth,size2+lineWidth+1):
        for j in range(0,size):
            texture_R[i,j] = 0

    texture_G = texture_R.copy()
    texture_B = texture_R.copy()
    return (texture_R, texture_G, texture_B)

def key_down(viewer, key, modifier):
    global extend_arrows, texture_R, texture_G, texture_B

    if key == ord('E'):
        extend_arrows = not extend_arrows

    if key < ord('1') or key > ord('8'):
        return False;

    viewer.data.clear()
    viewer.core.show_lines = False
    viewer.core.show_texture = False

    if key == ord('1'):
        # Cross field
        viewer.data.set_mesh(V, F)
        viewer.data.add_edges(B - global_scale*X1 if extend_arrows else B, B + global_scale*X1 , igl.eigen.MatrixXd([[1,0,0]]))
        viewer.data.add_edges(B - global_scale*X2 if extend_arrows else B, B + global_scale*X2 , igl.eigen.MatrixXd([[0,0,1]]))

    if key == ord('2'):
        # Bisector field
        viewer.data.set_mesh(V, F)
        viewer.data.add_edges(B - global_scale*BIS1 if extend_arrows else B, B + global_scale*BIS1 , igl.eigen.MatrixXd([[1,0,0]]))
        viewer.data.add_edges(B - global_scale*BIS2 if extend_arrows else B, B + global_scale*BIS2 , igl.eigen.MatrixXd([[0,0,1]]))

    if key == ord('3'):
        # Bisector field combed
        viewer.data.set_mesh(V, F)
        viewer.data.add_edges(B - global_scale*BIS1_combed if extend_arrows else B, B + global_scale*BIS1_combed , igl.eigen.MatrixXd([[1,0,0]]))
        viewer.data.add_edges(B - global_scale*BIS2_combed if extend_arrows else B, B + global_scale*BIS2_combed , igl.eigen.MatrixXd([[0,0,1]]))

    if key == ord('4'):
        # Singularities and cuts
        viewer.data.set_mesh(V, F)

        # Plot cuts
        l_count = Seams.sum()
        P1 = igl.eigen.MatrixXd(l_count,3)
        P2 = igl.eigen.MatrixXd(l_count,3)

        for i in range(0,Seams.rows()):
            for j in range(0,Seams.cols()):
                if Seams[i,j] != 0:
                    P1.setRow(l_count-1, V.row(F[i,j]))
                    P2.setRow(l_count-1, V.row(F[i,(j+1)%3]))
                    l_count = l_count - 1

        viewer.data.add_edges(P1, P2, igl.eigen.MatrixXd([[1, 0, 0]]))

        # Plot the singularities as colored dots (red for negative, blue for positive)
        for i in range(0,singularityIndex.size()):
            if singularityIndex[i] < 2 and singularityIndex[i] > 0:
                viewer.data.add_points(V.row(i),igl.eigen.MatrixXd([[1,0,0]]))
            elif singularityIndex[i] > 2:
                viewer.data.add_points(V.row(i),igl.eigen.MatrixXd([[1,0,0]]))

    if key == ord('5'):
        # Singularities and cuts, original field
        # Singularities and cuts
        viewer.data.set_mesh(V, F)
        viewer.data.add_edges(B - global_scale*X1_combed if extend_arrows else B, B + global_scale*X1_combed ,igl.eigen.MatrixXd([[1,0,0]]))
        viewer.data.add_edges(B - global_scale*X2_combed if extend_arrows else B, B + global_scale*X2_combed ,igl.eigen.MatrixXd([[0,0,1]]))

        # Plot cuts
        l_count = Seams.sum()

        P1 = igl.eigen.MatrixXd(l_count,3)
        P2 = igl.eigen.MatrixXd(l_count,3)

        for i in range(0, Seams.rows()):
            for j in range(0, Seams.cols()):
                if Seams[i,j] != 0:
                    P1.setRow(l_count-1,V.row(F[i,j]))
                    P2.setRow(l_count-1,V.row(F[i,(j+1)%3]))
                    l_count = l_count - 1

        viewer.data.add_edges(P1, P2, igl.eigen.MatrixXd([[1, 0, 0]]))

        # Plot the singularities as colored dots (red for negative, blue for positive)
        for i in range(0,singularityIndex.size()):
            if singularityIndex[i] < 2 and singularityIndex[i] > 0:
                viewer.data.add_points(V.row(i),igl.eigen.MatrixXd([[1,0,0]]))
            elif singularityIndex[i] > 2:
                viewer.data.add_points(V.row(i),igl.eigen.MatrixXd([[0,1,0]]))

    if key == ord('6'):
        # Global parametrization UV
        viewer.data.set_mesh(UV, FUV)
        viewer.data.set_uv(UV)
        viewer.core.show_lines = True

    if key == ord('7'):
        # Global parametrization in 3D
        viewer.data.set_mesh(V, F)
        viewer.data.set_uv(UV,FUV)
        viewer.core.show_texture = True

    if key == ord('8'):
        # Global parametrization in 3D with seams
        viewer.data.set_mesh(V, F)
        viewer.data.set_uv(UV_seams,FUV_seams)
        viewer.core.show_texture = True

    viewer.data.set_colors(igl.eigen.MatrixXd([[1,1,1]]))

    viewer.data.set_texture(texture_R, texture_B, texture_G)

    viewer.core.align_camera_center(viewer.data.V,viewer.data.F)

    return False

# Load a mesh in OFF format
igl.readOFF("../../tutorial/shared/3holes.off", V, F)

# Compute face barycenters
igl.barycenter(V, F, B)

# Compute scale for visualizing fields
global_scale =  .5*igl.avg_edge_length(V, F)

# Contrain one face
b  = igl.eigen.MatrixXi([[0]])
bc = igl.eigen.MatrixXd([[1,0,0]])

# Create a smooth 4-RoSy field
S = igl.eigen.MatrixXd()

igl.comiso.nrosy(V,F,b,bc,igl.eigen.MatrixXi(),igl.eigen.MatrixXd(),igl.eigen.MatrixXd(),4,0.5,X1,S)

# Find the the orthogonal vector
B1 = igl.eigen.MatrixXd()
B2 = igl.eigen.MatrixXd()
B3 = igl.eigen.MatrixXd()

igl.local_basis(V,F,B1,B2,B3)

X2 = igl.rotate_vectors(X1, igl.eigen.MatrixXd.Constant(1,1,pi/2), B1, B2)

gradient_size = 50
iterations = 0
stiffness = 5.0
direct_round = False

# Always work on the bisectors, it is more general
igl.compute_frame_field_bisectors(V, F, X1, X2, BIS1, BIS2)

# Comb the field, implicitly defining the seams
igl.comb_cross_field(V, F, BIS1, BIS2, BIS1_combed, BIS2_combed)

# Find the integer mismatches
igl.cross_field_missmatch(V, F, BIS1_combed, BIS2_combed, True, MMatch)

# Find the singularities
igl.find_cross_field_singularities(V, F, MMatch, isSingularity, singularityIndex);

# Cut the mesh, duplicating all vertices on the seams
igl.cut_mesh_from_singularities(V, F, MMatch, Seams)

# Comb the frame-field accordingly
igl.comb_frame_field(V, F, X1, X2, BIS1_combed, BIS2_combed, X1_combed, X2_combed)

# Global parametrization
igl.comiso.miq(V,
           F,
           X1_combed,
           X2_combed,
           MMatch,
           isSingularity,
           Seams,
           UV,
           FUV,
           gradient_size,
           stiffness,
           direct_round,
           iterations,
           5,
           True,
           True);

# Global parametrization (with seams, only for demonstration)
igl.comiso.miq(V,
         F,
         X1_combed,
         X2_combed,
         MMatch,
         isSingularity,
         Seams,
         UV_seams,
         FUV_seams,
         gradient_size,
         stiffness,
         direct_round,
         iterations,
         5,
         False);

# Plot the mesh
viewer = igl.viewer.Viewer()

# Replace the standard texture with an integer shift invariant texture
(texture_R, texture_G, texture_B) = line_texture()

# Plot the original mesh with a texture parametrization
key_down(viewer,ord('7'),0)

# Launch the viewer
viewer.callback_key_down = key_down
viewer.launch()