1PLW3D(3plplot) PLplot API PLW3D(3plplot)
2
6 plw3d - Configure the transformations required for projecting a 3D sur‐
7 face on a 2D window
8
10 plw3d(basex, basey, height, xmin, xmax, ymin, ymax, zmin, zmax, alt,
11 az)
12
14 Configure the transformations required for projecting a 3D surface on
15 an existing 2D window. Those transformations (see the PLplot documen‐
16 tation) are done to a rectangular cuboid enclosing the 3D surface which
17 has its limits expressed in 3D world coordinates and also normalized 3D
18 coordinates (used for interpreting the altitude and azimuth of the
19 viewing angle). The transformations consist of the linear transform
20 from 3D world coordinates to normalized 3D coordinates, and the 3D ro‐
21 tation of normalized coordinates required to align the pole of the new
22 3D coordinate system with the viewing direction specified by altitude
23 and azimuth so that x and y of the surface elements in that transformed
24 coordinate system are the projection of the 3D surface with given view‐
25 ing direction on the 2D window.
26 The enclosing rectangular cuboid for the surface plot is defined by
28 xmin, xmax, ymin, ymax, zmin and zmax in 3D world coordinates. It is
29 mapped into the same rectangular cuboid with normalized 3D coordinate
30 sizes of basex by basey by height so that xmin maps to -basex/2, xmax
31 maps to basex/2, ymin maps to -basey/2, ymax maps to basey/2, zmin maps
32 to 0 and zmax maps to height. The resulting rectangular cuboid in nor‐
33 malized coordinates is then viewed by an observer at altitude alt and
34 azimuth az. This routine must be called before plbox3(3plplot) or any
35 of the 3D surface plotting routines; plmesh(3plplot), plmeshc(3plplot),
36 plot3d(3plplot), plot3dc(3plplot), plot3dcl(3plplot),
37 plsurf3d(3plplot), plsurf3dl(3plplot) or plfill3(3plplot).
38 Redacted form: plw3d(basex, basey, height, xmin, xmax, ymin, ymax,
40 zmin, zmax, alt, az)
41 This function is examples 8, 11, 18, and 21.
43
45 basex (PLFLT(3plplot), input)
46 The normalized x coordinate size of the rectangular cuboid.
47 basey (PLFLT(3plplot), input)
49 The normalized y coordinate size of the rectangular cuboid.
50 height (PLFLT(3plplot), input)
52 The normalized z coordinate size of the rectangular cuboid.
53 xmin (PLFLT(3plplot), input)
55 The minimum x world coordinate of the rectangular cuboid.
56 xmax (PLFLT(3plplot), input)
58 The maximum x world coordinate of the rectangular cuboid.
59 ymin (PLFLT(3plplot), input)
61 The minimum y world coordinate of the rectangular cuboid.
62 ymax (PLFLT(3plplot), input)
64 The maximum y world coordinate of the rectangular cuboid.
65 zmin (PLFLT(3plplot), input)
67 The minimum z world coordinate of the rectangular cuboid.
68 zmax (PLFLT(3plplot), input)
70 The maximum z world coordinate of the rectangular cuboid.
71 alt (PLFLT(3plplot), input)
73 The viewing altitude in degrees above the xy plane of the rec‐
74 tangular cuboid in normalized coordinates.
75 az (PLFLT(3plplot), input)
77 The viewing azimuth in degrees of the rectangular cuboid in nor‐
78 malized coordinates. When az=0, the observer is looking face
79 onto the zx plane of the rectangular cuboid in normalized coor‐
80 dinates, and as az is increased, the observer moves clockwise
81 around that cuboid when viewed from above the xy plane.
82
85 Many developers (who are credited at http://plplot.org/credits.php)
86 have contributed to PLplot over its long history.
87
89 PLplot documentation at http://plplot.org/documentation.php.
90 February, 2022 PLW3D(3plplot)