Scripts: markhidden.py

# ------------------------------------------------------------------------------
# Create a marker set placing a marker at each hidden vertex of a surface piece.
#
def mark_hidden_vertices(plist, radius = 1.0, rgba = (1,1,1,1),
                         marker_set = None):

    for p in plist:
        m = p.triangleAndEdgeMask
        v,t = p.geometry
        hidden = hidden_vertices(t, m)
        if hidden:
            if marker_set is None:
                from VolumePath.markerset import Marker_Set
                marker_set = Marker_Set('vertices')
                marker_set.set_transform(p.model.openState.xform)
            positions = v[tuple(hidden),:]
            transform_points(positions, p.model.openState.xform,
                             marker_set.transform())
            for xyz in positions:
                marker_set.place_marker(xyz, rgba, radius)

# ------------------------------------------------------------------------------
#
def hidden_vertices(t, m):
    vis = set()
    all = set()
    for ti, tm in enumerate(m):
        if tm & 0x8:
            v0,v1,v2 = t[ti,:]
            for v in (v0,v1,v2):
                all.add(v)
            if tm & 0x5:         # Edge 0-1 or 2-0 shown
                vis.add(v0)
            if tm & 0x3:         # Edge 0-1 or 1-2 shown
                vis.add(v1)
            if tm & 0x6:         # Edge 1-2 or 2-0 shown
                vis.add(v2)
    hidden = all.difference(vis)
    return hidden

# ------------------------------------------------------------------------------
#
def transform_points(points, from_xf, to_xf):

    from chimera import Xform
    xf = Xform()
    xf.premultiply(from_xf)
    xf.premultiply(to_xf.inverse())
    from Matrix import xform_matrix
    tf = xform_matrix(xf)
    import _contour
    _contour.affine_transform_vertices(points, tf)

# ------------------------------------------------------------------------------
#
import Surface
plist = Surface.selected_surface_pieces()
mark_hidden_vertices(plist)