55 lines
1.2 KiB
Python
Executable File
55 lines
1.2 KiB
Python
Executable File
# 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 igl
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V = igl.eigen.MatrixXd()
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F = igl.eigen.MatrixXi()
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# Load a mesh in OFF format
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igl.readOFF("../../tutorial/shared/cheburashka.off", V, F)
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# Read scalar function values from a file, U: #V by 1
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U = igl.eigen.MatrixXd()
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igl.readDMAT("../../tutorial/shared/cheburashka-scalar.dmat",U)
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U = U.col(0)
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# Compute gradient operator: #F*3 by #V
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G = igl.eigen.SparseMatrixd()
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igl.grad(V,F,G)
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# Compute gradient of U
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GU = (G*U).MapMatrix(F.rows(),3)
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# Compute gradient magnitude
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GU_mag = GU.rowwiseNorm()
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viewer = igl.viewer.Viewer()
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viewer.data.set_mesh(V, F)
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# Compute pseudocolor for original function
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C = igl.eigen.MatrixXd()
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igl.jet(U,True,C)
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# Or for gradient magnitude
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# igl.jet(GU_mag,True,C)
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viewer.data.set_colors(C);
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# Average edge length divided by average gradient (for scaling)
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max_size = igl.avg_edge_length(V,F) / GU_mag.mean()
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# Draw a black segment in direction of gradient at face barycenters
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BC = igl.eigen.MatrixXd()
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igl.barycenter(V,F,BC)
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black = igl.eigen.MatrixXd([[0.0,0.0,0.0]])
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viewer.data.add_edges(BC,BC+max_size*GU, black)
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# Hide wireframe
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viewer.core.show_lines = False
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viewer.launch()
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