eic-opticks/ana/cube.py

0001 #!/usr/bin/env python
0002 """
0003 See cubeplt.py for 3d plotting of the cubes
0004 """
0005 import numpy as np
0006
0007 def make_pyvista_indices(indices):
0008     """
0009     :param indices:  (nface,3) triangles OR (nface,4) quads
0010     :return ii: vista type list
0011     """
0012     sh = list(indices.shape)
0013     last = sh[-1]
0014     assert last in (3,4)
0015     sh[-1] = last+1
0016     ii = np.zeros(sh, dtype=np.int32)
0017     ii[:,1:] = indices
0018     ii[:,0] = last
0019     return ii
0020
0021
0022 def make_cube_oxyz(oxyz):
0023     """
0024     :param oxyz: (4,3) : origin and orthogonal surrounding points nominally
0025                          assumed in +X,+Y,+Z directions relative to first point
0026
0027
0028               (YZ)      (XYZ)
0029                6.........7
0030               /.        /|
0031              / .       / |
0032             /  .      /  |
0033            3.........5   |
0034            |   .     |   |
0035            |   2.....|...4
0036          Z |  /      |  /
0037            | / Y     | /
0038            |/        |/
0039            0---------1
0040                 X
0041
0042     """
0043     o = oxyz[0]
0044     v = oxyz[1:] - o   # three : assumed orthogonal base vectors
0045
0046     verts = np.zeros([8,3], dtype=np.float32)
0047     verts[:4] = oxyz
0048     verts[4] = o + v[0] + v[1]        # XY
0049     verts[5] = o + v[0] + v[2]        # XZ
0050     verts[6] = o + v[1] + v[2]        # YZ
0051     verts[7] = o + v[0] + v[1] + v[2] # XYZ
0052
0053     indices = np.array([
0054            [0,1,5,3],    # thumb-out   (outwards normal)
0055            [1,4,7,5],    # thumb-right (outwards normal)
0056            [4,2,6,7],    # thumb-back  (outwards normal)
0057            [0,3,6,2],    # thumb-left  (outwards normal)
0058            [0,2,4,1],    # thumb-down  (outwards normal)
0059            [5,7,6,3]],   # thumb-up    (outwards normal)
0060            dtype=np.int32)
0061
0062     pv_indices = make_pyvista_indices(indices)
0063     faces = verts[indices]
0064     assert verts.shape == (8,3)
0065     assert indices.shape == (6,4)
0066     assert pv_indices.shape == (6,5)
0067     assert faces.shape == (6,4,3)
0068     return verts, faces, pv_indices
0069
0070
0071 def make_cube_bbox(bbox):
0072     """
0073     :param bbox: (2,3)  mi,mx
0074
0075                          mx
0076               (YZ)      (XYZ)
0077                6.........7
0078               /.        /|
0079              / .       / |
0080             /  .      /  |
0081            3.........5   |
0082            |   .     |   |
0083            |   2.....|...4
0084          Z |  /      |  /
0085            | / Y     | /
0086            |/        |/
0087            0---------1
0088          mi     X
0089
0090     """
0091     assert bbox.shape == (2,3)
0092     mi, mx = bbox
0093     verts = np.zeros([8,3], dtype=np.float32)
0094     verts[0] = [mi[0], mi[1], mi[2]]  # ---
0095     verts[1] = [mx[0], mi[1], mi[2]]  # X--
0096     verts[2] = [mi[0], mx[1], mi[2]]  # -Y-
0097     verts[3] = [mi[0], mi[1], mx[2]]  # --Z
0098     verts[4] = [mx[0], mx[1], mi[2]]  # XY-
0099     verts[5] = [mx[0], mi[1], mx[2]]  # X-Z
0100     verts[6] = [mi[0], mx[1], mx[2]]  # -YZ
0101     verts[7] = [mx[0], mx[1], mx[2]]  # XYZ
0102
0103     indices = np.array([
0104            [0,1,5,3],    # thumb-out   (outwards normal)
0105            [1,4,7,5],    # thumb-right (outwards normal)
0106            [4,2,6,7],    # thumb-back  (outwards normal)
0107            [0,3,6,2],    # thumb-left  (outwards normal)
0108            [0,2,4,1],    # thumb-down  (outwards normal)
0109            [5,7,6,3]],   # thumb-up    (outwards normal)
0110            dtype=np.int32)
0111     pv_indices = make_pyvista_indices(indices)
0112
0113     faces = verts[indices]
0114     assert verts.shape == (8,3)
0115     assert indices.shape == (6,4)
0116     assert pv_indices.shape == (6,5)
0117     assert faces.shape == (6,4,3)
0118
0119     return verts, faces, pv_indices
0120
0121
0122 def make_cube(cube):
0123     """
0124     :param cube: shape of either (4,3) or (2,3)
0125     """
0126     if cube.shape == (4,3):
0127         return make_cube_oxyz(cube)
0128     elif cube.shape == (2,3):
0129         return make_cube_bbox(cube)
0130     else:
0131         assert 0, ("cube specification array not handled", cube.shape)
0132     pass
0133
0134
0135 if __name__ == '__main__':
0136
0137     oxyz = np.array([(0,0,0), (100,0,0), (0,100,0), (0,0,100)], dtype=np.float32)
0138     bbox = np.array([(0,0,0),(100,100,100)], dtype=np.float32)
0139
0140     points0, faces0, indices0 = make_cube(oxyz)
0141     points1, faces1, indices1 = make_cube(bbox)
0142
0143     assert np.all( points0 == points1 )
0144     assert np.all( faces0 == faces1 )
0145
0146
0147
0148