Revisions to Creating sinusoidal struts using bpy

Adding gif

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edited Jul 17, 2017 at 9:05

TLousky

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Setting values that generate the desired shape.

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edited Jul 16, 2017 at 13:26

TLousky

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This can be fairly easily expanded to generate other shapes, or non-quad based struts. Here you can control the amplitude for the Z and X components separately, as well as the width (thickness) of the 3D strut via the width global and zw / xw variables within the loop.

import bpy, bmesh, math
from mathutils import Vector
import numpy as np

numPoints  = 100
yMin       = -0.53 * np.pi 
yMax       = 3.5 1 * np.pi
width      = 0.5

def strut( x, node_dist = 5, amp = 1 ):
    """ Takes 1D array x, creates shape y values """
    return amp / 2 * np.cos(x) + amp / 2  # adjusting position and amplitude

bm    = bmesh.new() # Generate bmesh object
loops = []          # Strut major longitudinal loops array

# Calculate vertex coordinates
# Essentially generate 4 longitudinal loops that represent the top, bottom. left and right edge loops of the strut
y = np.linspace( yMin, yMax, numPoints )
for zw, xw in zip( [1, 0, -1, 0], [0, -1, 0, 1] ):
    yz = np.linspacestrut( yMin, yMaxy, numPoints )
    zamp = strut( y2 ) + zw * width
    x = strut( y, amp = 0 ) + xw * width

    loop = [ 
        bm.verts.new( Vector(( xi, yi, zi )) ) 
        for xi, yi, zi in zip( x, y, z ) 
    ]

    loops.append( loop )

# Add faces
for i in range( len( loops ) ):
    for j in range( len( loops[i] ) - 1 ):
        verts = []
        if i == len( loops ) - 1:
            verts.append( loops[0][j] )
            verts.append( loops[0][j+1] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i][j] )
        else:
            verts.append( loops[i][j] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i+1][j+1] )
            verts.append( loops[i+1][j] )

        bm.faces.new(verts)

# Add caps faces
for i in [0, len( loops[0] ) - 1 ]:
    bm.faces.new([ loops[j][i] for j in range(len(loops)) ])

# Generate mesh data and object, and link to scene
m = bpy.data.meshes.new('strut')
bm.to_mesh(m)

o = bpy.data.objects.new('strut', m)
bpy.context.scene.objects.link( o )

This can be fairly easily expanded to generate other shapes, or non-quad based struts. Here you can control the amplitude for the Z and X components separately, as well as the width (thickness) of the 3D strut.

import bpy, bmesh, math
from mathutils import Vector
import numpy as np

numPoints  = 100
yMin       = -0.5 * np.pi 
yMax       = 3.5  * np.pi
width      = 0.5

def strut( x, node_dist = 5, amp = 1 ):
    """ Takes 1D array x, creates shape y values """
    return amp / 2 * np.cos(x) + amp / 2  # adjusting position and amplitude

bm    = bmesh.new() # Generate bmesh object
loops = []          # Strut major longitudinal loops array

# Calculate vertex coordinates
# Essentially generate 4 longitudinal loops that represent the top, bottom. left and right edge loops of the strut
for zw, xw in zip( [1, 0, -1, 0], [0, -1, 0, 1] ):
    y = np.linspace( yMin, yMax, numPoints )
    z = strut( y ) + zw * width
    x = strut( y ) + xw * width

    loop = [ 
        bm.verts.new( Vector(( xi, yi, zi )) ) 
        for xi, yi, zi in zip( x, y, z ) 
    ]

    loops.append( loop )

# Add faces
for i in range( len( loops ) ):
    for j in range( len( loops[i] ) - 1 ):
        verts = []
        if i == len( loops ) - 1:
            verts.append( loops[0][j] )
            verts.append( loops[0][j+1] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i][j] )
        else:
            verts.append( loops[i][j] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i+1][j+1] )
            verts.append( loops[i+1][j] )

        bm.faces.new(verts)

# Add caps faces
for i in [0, len( loops[0] ) - 1 ]:
    bm.faces.new([ loops[j][i] for j in range(len(loops)) ])

# Generate mesh data and object, and link to scene
m = bpy.data.meshes.new('strut')
bm.to_mesh(m)

o = bpy.data.objects.new('strut', m)
bpy.context.scene.objects.link( o )

This can be fairly easily expanded to generate other shapes, or non-quad based struts. Here you can control the width (thickness) of the 3D strut via the width global and zw / xw variables within the loop.

import bpy, bmesh, math
from mathutils import Vector
import numpy as np

numPoints  = 100
yMin       = -3 * np.pi 
yMax       = 1 * np.pi
width      = 0.5

def strut( x, node_dist = 5, amp = 1 ):
    """ Takes 1D array x, creates shape y values """
    return amp / 2 * np.cos(x) + amp / 2  # adjusting position and amplitude

bm    = bmesh.new() # Generate bmesh object
loops = []          # Strut major longitudinal loops array

# Calculate vertex coordinates
# Essentially generate 4 longitudinal loops that represent the top, bottom. left and right edge loops of the strut
y = np.linspace( yMin, yMax, numPoints )
for zw, xw in zip( [1, 0, -1, 0], [0, -1, 0, 1] ):
    z = strut( y, amp = 2 ) + zw * width
    x = strut( y, amp = 0 ) + xw * width

    loop = [ 
        bm.verts.new( Vector(( xi, yi, zi )) ) 
        for xi, yi, zi in zip( x, y, z ) 
    ]

    loops.append( loop )

# Add faces
for i in range( len( loops ) ):
    for j in range( len( loops[i] ) - 1 ):
        verts = []
        if i == len( loops ) - 1:
            verts.append( loops[0][j] )
            verts.append( loops[0][j+1] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i][j] )
        else:
            verts.append( loops[i][j] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i+1][j+1] )
            verts.append( loops[i+1][j] )

        bm.faces.new(verts)

# Add caps faces
for i in [0, len( loops[0] ) - 1 ]:
    bm.faces.new([ loops[j][i] for j in range(len(loops)) ])

# Generate mesh data and object, and link to scene
m = bpy.data.meshes.new('strut')
bm.to_mesh(m)

o = bpy.data.objects.new('strut', m)
bpy.context.scene.objects.link( o )

Replacing loop with list comprehension

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edited Jul 16, 2017 at 13:16

TLousky

16.1k
1
42
73

import bpy, bmesh, math
from mathutils import Vector
import numpy as np

numPoints  = 100
yMin       = -0.5 * np.pi 
yMax       = 3.5  * np.pi
width      = 0.5

def strut( x, node_dist = 5, amp = 1 ):
    """ Takes 1D array x, creates shape y values """
    return amp / 2 * np.cos(x) + amp / 2  # adjusting position and amplitude

bm    = bmesh.new() # Generate bmesh object
loops = []          # Strut major longitudinal loops array

# Calculate vertex coordinates
# Essentially generate 4 longitudinal loops that represent the top, bottom. left and right edge loops of the strut
for zw, xw in zip( [1, 0, -1, 0], [0, -1, 0, 1] ):
    y = np.linspace( yMin, yMax, numPoints )
    z = strut( y ) + zw * width
    x = strut( y ) + xw * width

    loop = [][ 
    for xi, yi, zi inbm.verts.new( zipVector(( xxi, yyi, zzi ):
) )  
      loop.append( bm.verts.new( Vector((for xi, yi, zi ))in )zip( x, y, z ) 
    ]

    loops.append( loop )

# Add faces
for i in range( len( loops ) ):
    for j in range( len( loops[i] ) - 1 ):
        verts = []
        if i == len( loops ) - 1:
            verts.append( loops[0][j] )
            verts.append( loops[0][j+1] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i][j] )
        else:
            verts.append( loops[i][j] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i+1][j+1] )
            verts.append( loops[i+1][j] )

        bm.faces.new(verts)

# Add caps faces
for i in [0, len( loops[0] ) - 1 ]:
    bm.faces.new([ loops[j][i] for j in range(len(loops)) ])

# Generate mesh data and object, and link to scene
m = bpy.data.meshes.new('strut')
bm.to_mesh(m)

o = bpy.data.objects.new('strut', m)
bpy.context.scene.objects.link( o )

import bpy, bmesh, math
from mathutils import Vector
import numpy as np

numPoints  = 100
yMin       = -0.5 * np.pi 
yMax       = 3.5  * np.pi
width      = 0.5

def strut( x, node_dist = 5, amp = 1 ):
    """ Takes 1D array x, creates shape y values """
    return amp / 2 * np.cos(x) + amp / 2  # adjusting position and amplitude

bm    = bmesh.new() # Generate bmesh object
loops = []          # Strut major longitudinal loops array

# Calculate vertex coordinates
# Essentially generate 4 longitudinal loops that represent the top, bottom. left and right edge loops of the strut
for zw, xw in zip( [1, 0, -1, 0], [0, -1, 0, 1] ):
    y = np.linspace( yMin, yMax, numPoints )
    z = strut( y ) + zw * width
    x = strut( y ) + xw * width

    loop = []
    for xi, yi, zi in zip( x, y, z ):
        loop.append( bm.verts.new( Vector(( xi, yi, zi )) ) )

    loops.append( loop )

# Add faces
for i in range( len( loops ) ):
    for j in range( len( loops[i] ) - 1 ):
        verts = []
        if i == len( loops ) - 1:
            verts.append( loops[0][j] )
            verts.append( loops[0][j+1] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i][j] )
        else:
            verts.append( loops[i][j] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i+1][j+1] )
            verts.append( loops[i+1][j] )

        bm.faces.new(verts)

# Add caps faces
for i in [0, len( loops[0] ) - 1 ]:
    bm.faces.new([ loops[j][i] for j in range(len(loops)) ])

# Generate mesh data and object, and link to scene
m = bpy.data.meshes.new('strut')
bm.to_mesh(m)

o = bpy.data.objects.new('strut', m)
bpy.context.scene.objects.link( o )

import bpy, bmesh, math
from mathutils import Vector
import numpy as np

numPoints  = 100
yMin       = -0.5 * np.pi 
yMax       = 3.5  * np.pi
width      = 0.5

def strut( x, node_dist = 5, amp = 1 ):
    """ Takes 1D array x, creates shape y values """
    return amp / 2 * np.cos(x) + amp / 2  # adjusting position and amplitude

bm    = bmesh.new() # Generate bmesh object
loops = []          # Strut major longitudinal loops array

# Calculate vertex coordinates
# Essentially generate 4 longitudinal loops that represent the top, bottom. left and right edge loops of the strut
for zw, xw in zip( [1, 0, -1, 0], [0, -1, 0, 1] ):
    y = np.linspace( yMin, yMax, numPoints )
    z = strut( y ) + zw * width
    x = strut( y ) + xw * width

    loop = [ 
        bm.verts.new( Vector(( xi, yi, zi )) )  
        for xi, yi, zi in zip( x, y, z ) 
    ]

    loops.append( loop )

# Add faces
for i in range( len( loops ) ):
    for j in range( len( loops[i] ) - 1 ):
        verts = []
        if i == len( loops ) - 1:
            verts.append( loops[0][j] )
            verts.append( loops[0][j+1] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i][j] )
        else:
            verts.append( loops[i][j] )
            verts.append( loops[i][j + 1] )
            verts.append( loops[i+1][j+1] )
            verts.append( loops[i+1][j] )

        bm.faces.new(verts)

# Add caps faces
for i in [0, len( loops[0] ) - 1 ]:
    bm.faces.new([ loops[j][i] for j in range(len(loops)) ])

# Generate mesh data and object, and link to scene
m = bpy.data.meshes.new('strut')
bm.to_mesh(m)

o = bpy.data.objects.new('strut', m)
bpy.context.scene.objects.link( o )

Removing useless list from zip and setting nicer width default value, removing unneded amplitude vars as it is defined in function

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edited Jul 16, 2017 at 13:09

TLousky

16.1k
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42
73

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Fixing bug in Z and X formulae

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edited Jul 16, 2017 at 13:01

TLousky

16.1k
1
42
73

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Improving explanation

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edited Jul 16, 2017 at 12:29

TLousky

16.1k
1
42
73

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created Jul 16, 2017 at 12:22

TLousky

16.1k
1
42
73

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