libigl_Martin/python/402_PolyharmonicDeformation.py

import igl

global z_max, z_dir, k, resolve, V, U, Z, F, b, bc

z_max = 1.0
z_dir = -0.03
k = 2
resolve = True


V = igl.eigen.MatrixXd()
U = igl.eigen.MatrixXd()

Z = igl.eigen.MatrixXd()

F = igl.eigen.MatrixXi()
b = igl.eigen.MatrixXi()

bc = igl.eigen.MatrixXd()

def pre_draw(viewer):
    global z_max, z_dir, k, resolve, V, U, Z, F, b, bc

    if resolve:
        igl.harmonic(V,F,b,bc,k,Z)
        resolve = False

    U.setCol(2,z_max*Z)
    viewer.data.set_vertices(U)
    viewer.data.compute_normals()

    if viewer.core.is_animating:
        z_max += z_dir
        z_dir *= (-1.0 if z_max>=1.0 or z_max<=0.0 else 1.0)

    return False

def key_down(viewer, key, mods):
    global z_max, z_dir, k, resolve, V, U, Z, F, b, bc

    if key == ord(' '):
        viewer.core.is_animating = not viewer.core.is_animating
    elif key == ord('.'):
        k = k + 1
        k = (4 if k>4 else k)
        print k
        resolve = True
    elif key == ord(','):
        k = k - 1
        k = (1 if k<1 else k)
        print k
        resolve = True
    return True


igl.readOBJ("../tutorial/shared/bump-domain.obj",V,F)
U = igl.eigen.MatrixXd(V)

# Find boundary vertices outside annulus

Vrn = V.rowwiseNorm()
is_outer = [Vrn[i]-1.00 > -1e-15 for i in range(0,V.rows())]
is_inner = [Vrn[i]-0.15 <  1e-15 for i in range(0,V.rows())]
in_b = [ is_outer[i] or is_inner[i] for i in range(0,len(is_outer))]

b = igl.eigen.MatrixXi([[i for i in range(0,V.rows()) if (in_b[i])]]).transpose();

bc.resize(b.size(),1)

for bi in range(0,b.size()):
    bc[bi] = (0.0 if is_outer[b[bi]] else 1.0)

# Pseudo-color based on selection
C = igl.eigen.MatrixXd(F.rows(),3)
purple = igl.eigen.MatrixXd([[80.0/255.0,64.0/255.0,255.0/255.0]])
gold   = igl.eigen.MatrixXd([[255.0/255.0,228.0/255.0,58.0/255.0]])

for f in range(0,F.rows()):
    if( in_b[F[f,0]] and in_b[F[f,1]] and in_b[F[f,2]]):
        C.setRow(f,purple)
    else:
        C.setRow(f,gold)

# Plot the mesh with pseudocolors
viewer = igl.viewer.Viewer()
viewer.data.set_mesh(U, F)
viewer.core.show_lines = False
viewer.data.set_colors(C)
# viewer.core.trackball_angle = igl.eigen.Quaterniond(0.81,-0.58,-0.03,-0.03)
# viewer.core.trackball_angle.normalize()
viewer.callback_pre_draw = pre_draw
viewer.callback_key_down = key_down
viewer.core.is_animating = True
viewer.core.animation_max_fps = 30.0
print("Press [space] to toggle animation.")
print("Press '.' to increase k.")
print("Press ',' to decrease k.")
viewer.launch();