[x3d-public] example python code using numpy library

[Brutzman, Donald (Don) (CIV)]

[cc: Moritz]

Looks like our enterprise mail server (configured by Microsoft in a cloud)
scrubs all .py attachments.

I was able to retrieve your example by going to the Web3D-archived version
at

* http://web3d.org/pipermail/x3d-public_web3d.org/2022-February/016818.html

and then saving attachment.bin as NumpyExample.py

Thank you Vince, looks interesting.  Am also copying source here in case
anyone has further retrieval difficulties.

NumpyExample.py
======================================
"""
Script to demonstrate setting the values of the coordinates, colors (by
vertex), and index arrays defining
an IndexedTriangleSet from data values in numpy arrays.
Tested Feb 24 2022 with x3d version 4.0.51   installed with pip
Vince Marchetti 24 Feb 2022
license : https://creativecommons.org/licenses/by/4.0/
"""
from x3d.x3d import *
import numpy as np
def colored_tetrahedron( radius ):
    """
    returns (3,) tuple of numpy arrays
    points_coordinate : a (N,3) array of vertex coordinates
    points_colors : (N,3) array of colors
    face_indices : (K,3) array of integer indices into points_* arrays
    
    where N = number of vertices in mesh (N=4 for this tetrahedron)
          K = number of triangle faces in mesh (K=5 for tetrahedron)
          
    defines a mesh for a tetrahedron inscribed in sphere of with radius
specified by argument
    centered at origin
    """
    point_coordinates = np.array([
        ( 0.000,  1.000,   0.000),
        (-0.816, -0.344,   0.471),
        ( 0.816, -0.344,   0.471),
        ( 0.000, -0.344,  -0.942),
    ]) * radius
    
    point_colors = np.array([
        (1.00,1.00,0.40),
        (0.70,0.40,1.00),
        (0.00,0.80,0.00),
        (1.00,0.80,0.90),
    ])
    face_indices = np.array([
        (0,1,2),
        (0,2,3),
        (0,3,1),
        (3,2,1)
    ])
    
    return point_coordinates,point_colors,face_indices
    
    
point_coordinates,point_colors,face_indices = colored_tetrahedron( 2.0 )
newModel=X3D(profile='Immersive',version='3.3',
  head=head(
    children=[
    meta(content='NumpyExample.x3d',name='title'),
    meta(content='example of using Numpy library to generate coordinate
geometry and color',name='description'),
    meta(content='24 Feb 2022',name='created'),
    meta(content='Vince Marchetti',name='creator'),
 
meta(content='https://www.web3d.org/x3d/content/examples/license.html',name=
'license')
  ]),
  Scene=Scene(
    
    children=[
    WorldInfo(title='NumpyExample.x3d'),
    Viewpoint(DEF='ViewUpClose', description='Initial Viewpoint'),
    Shape(geometry=IndexedTriangleSet(
                # following code converts rank-2 numpy array of integers
into a python list for setting value of index field
                index = list( face_indices.flatten() ),
                
                # following code converts rank-2 numpy array of float values
into a Python list of Python tuples of floats
                # to set x3d values of type MFVec3f and MFColor
                coord = Coordinate( point = [ tuple(pt) for pt in
point_coordinates] ),
                color = Color( color = [tuple(c) for c in point_colors])
                )
          )
    ])
) 
newModelXML= newModel.XML() 
print(newModelXML)
======================================

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br        brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA    +1.831.656.2149
X3D graphics, virtual worlds, Navy robotics
https://faculty.nps.edu/brutzman

-----Original Message-----
From: vmarchetti at kshell.com <vmarchetti at kshell.com> 
Sent: Friday, February 25, 2022 3:50 AM
To: X3D-Public <x3d-public at web3d.org>; Brutzman, Donald (Don) (CIV)
<brutzman at nps.edu>
Subject: example python code using numpy library

Attached is a Python script that defines the coordinates, colors, and face
indices for a tetrahedron as numpy rank-2 arrays, then converts those values
in order to initialize the field values for an x3d IndexedTriangleSet node.

This may serve as a demonstration example for using numpy together with the
x3d package.

This script runs with the pip installation of x3d and was tested at version
4.0.51

Vince Marchetti
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 5353 bytes
Desc: not available
URL: <http://web3d.org/pipermail/x3d-public_web3d.org/attachments/20220227/afa17eb4/attachment.p7s>