101 lines
2.2 KiB
Python
101 lines
2.2 KiB
Python
# Add the igl library to the modules search path
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import sys, os
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sys.path.insert(0, os.getcwd() + "/../")
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import pyigl as igl
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V = igl.eigen.MatrixXd()
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F = igl.eigen.MatrixXi()
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igl.readOFF("../../tutorial/shared/cheburashka.off",V,F)
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# Two fixed points
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# Left hand, left foot
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b = igl.eigen.MatrixXi([[4331],[5957]])
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bc = igl.eigen.MatrixXd([[1],[-1]])
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# Construct Laplacian and mass matrix
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L = igl.eigen.SparseMatrixd()
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M = igl.eigen.SparseMatrixd()
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Minv = igl.eigen.SparseMatrixd()
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Q = igl.eigen.SparseMatrixd()
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igl.cotmatrix(V,F,L)
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igl.massmatrix(V,F,igl.MASSMATRIX_TYPE_VORONOI,M)
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igl.invert_diag(M,Minv)
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# Bi-Laplacian
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Q = L * (Minv * L);
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# Zero linear term
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B = igl.eigen.MatrixXd.Zero(V.rows(),1);
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Z = igl.eigen.MatrixXd()
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Z_const = igl.eigen.MatrixXd()
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# Alternative, short hand
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mqwf = igl.min_quad_with_fixed_data()
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# Empty constraints
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Beq = igl.eigen.MatrixXd()
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Aeq = igl.eigen.SparseMatrixd()
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igl.min_quad_with_fixed_precompute(Q,b,Aeq,True,mqwf)
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igl.min_quad_with_fixed_solve(mqwf,B,bc,Beq,Z)
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# Constraint forcing difference of two points to be 0
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Aeq = igl.eigen.SparseMatrixd(1,V.rows())
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# Right hand, right foot
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Aeq.insert(0,6074,1)
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Aeq.insert(0,6523,-1)
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Aeq.makeCompressed()
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Beq = igl.eigen.MatrixXd([[0]])
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igl.min_quad_with_fixed_precompute(Q,b,Aeq,True,mqwf)
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igl.min_quad_with_fixed_solve(mqwf,B,bc,Beq,Z_const)
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# Pseudo-color based on solution
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global C
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C = igl.eigen.MatrixXd()
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global C_const
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C_const = igl.eigen.MatrixXd()
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global toggle
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toggle = True
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# Use same color axes
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min_z = min(Z.minCoeff(),Z_const.minCoeff())
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max_z = max(Z.maxCoeff(),Z_const.maxCoeff())
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igl.jet( Z,min_z,max_z,C);
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igl.jet(Z_const,min_z,max_z,C_const);
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# Plot the mesh with pseudocolors
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viewer = igl.viewer.Viewer()
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viewer.data.set_mesh(V, F)
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viewer.core.show_lines = False
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viewer.data.set_colors(C)
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def key_down(viewer,key,mode):
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if key == ord(' '):
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global toggle
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global C
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global C_const
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if toggle:
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viewer.data.set_colors(C)
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else:
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viewer.data.set_colors(C_const)
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toggle = not toggle;
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return True
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return False
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viewer.callback_key_down = key_down
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print("Press [space] to toggle between unconstrained and constrained.")
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viewer.launch()
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