Scripts: edgeband.py

# Show colored bands at the edge of a surface zone.

def make_edge_bands(surf_piece):
    p = surf_piece
    from numpy import array, bool, zeros, logical_or, logical_and, logical_not
    # Find mask of shown triangles.
    t = array(p.triangleAndEdgeMask & 0x8, bool)
    va, ta = p.geometry
    # Compute mask of shown vertices
    vs = zeros((len(va),), bool)
    for a in (0,1,2):
        vs[ta[t,a]] = 1
    # Find mask of triangles that have a shown vertex
    ts = logical_or(vs[ta[:,0]], vs[ta[:,1]])
    logical_or(ts, vs[ta[:,2]], ts)
    # Find mask of unshown triangles having a shown vertex
    logical_and(ts, logical_not(t), ts)
    # Copy these triangles to a new surface piece
    if ts.sum() == 0:
        return None
    # Put bands in a new surface model so zone does not apply to them.
    from _surface import SurfaceModel
    s = SurfaceModel()
    s.name = p.model.name + ' bands'
    bp = s.newPiece()
    bp.geometry = va, ta[ts,:]
    bp.normals = p.normals
    bp.color = (0,1,0,1)        # Green
    from chimera import openModels
    openModels.add([s])
    s.openState.xform = p.model.openState.xform
    return s

import Surface
for p in Surface.selected_surface_pieces():
    make_edge_bands(p)