Pycavalier is a Python library to draw 3D objects using an oblique projection with Matplotlib.
The orientation of the projection is with respect to the observer, and the vertical direction is kept track of.
from pycavalier import projection_tools as pt
from pylab import *
# create a view point
viewpoint = pt.viewpoint( latitude = 0.9*pi/2., longitude = pi/10. )
# show refrence frame
viewpoint.show_reference_frame()
# create disk
radius = 2
theta = linspace(0,2*pi,100)
center = array( [ 3, 2.5, 0 ] )
circle = center + array( [ radius*cos(theta), radius*sin(theta), 0.*theta ] ).T
# show disk
viewpoint.plot_points( circle, '--', lw = 3 )
axis('equal')
show()from pycavalier import projection_tools as pt
from pylab import *
# create a view point
viewpoint = pt.viewpoint( latitude = 0.9*pi/2., longitude = pi/10. )
# create box
sides = [ [ [0,0,1], [0,1,1], [1,1,1], [1,0,1] ] ]
sides += [ [ [1,0,0], [1,0,1], [1,1,1], [1,1,0] ] ]
sides += [ [ [0,1,0], [0,1,1], [1,1,1], [1,1,0] ] ]
# show box
for side in sides :
viewpoint.plot_patch( side, color = 'tab:brown', edgecolor = 'black' )
axis('equal')
show()from pycavalier import projection_tools as pt
from pylab import *
# define the vertical direction
tilt_angles = [ 0, -pi/8, -pi/4 ]
for tilt_angle in tilt_angles :
# create viewpoint with tilt
viewpoint = pt.viewpoint( latitude = 0.9*pi/2., longitude = pi/10., plummet = [ 0,-sin(tilt_angle), -cos(tilt_angle) ] )
# translate reference frame
viewpoint.reference_frame['center'] = viewpoint.reference_frame['center'] + array( [-6, 0, 0] )
# show refrence frame and plummet
viewpoint.show_reference_frame()
viewpoint.show_plummet()
axis('equal')
show()from pycavalier import projection_tools as pt
from pylab import *
# create a view point
viewpoint = pt.viewpoint( latitude = 0.7*pi/2., longitude =-.4*pi/2. )
viewpoint.show_reference_frame()
# create sandy wavy bed
x = linspace( 0, 6*pi, 100 )
z = -.5*cos(x)
points = array( [ x, 0*x, z ] ).T
width = array([0, 3, 0])
patches = [ [ points[i], points[i+1], points[i+1] + width, points[i] + width] for i in range( len(points) - 1 ) ]
# show bed patches
for patch in patches :
viewpoint.plot_patch( patch, color = 'tab:brown', alpha = .3, edgecolor = 'none' )
dots = pt.dotify( patch, 30 )
viewpoint.plot_points( dots, '.', ms = 2, color = 'tab:brown', alpha = .3 )
axis('equal')
show()