FreeCAD vector math library: Difference between revisions

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== Introduction == <!--T:4-->

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This is a python file containing a couple of useful functions to manipulate freecad vectors. Just paste the following code in a python file, and import that file in your python script in order to use them. This library is included in the [[Draft Module]] and can be accessed like this from the python interpreter:
This is a [[Python|Python]] module containing a couple of useful functions to manipulate vectors. This library is included in the [[Draft_Workbench]] and can be accessed like this from the Python interpreter:
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{{Code|code=
import DraftVecUtils
import DraftVecUtils
}}
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<!--T:5-->
Please note that this module was created a long time ago, when the {{incode|Vector}} class didn't have many of its methods. Now these operations can be done by the Vector class itself.

<!--T:6-->
Although the {{incode|DraftVecUtils}} module still exists, and it is still used inside the [[Draft_Workbench|Draft Workbench]], it is probably better to use the {{incode|Vector}} methods directly for new developments.

== Functions == <!--T:7-->

<!--T:2-->
<!--T:2-->
Vectors are the building bricks of almost all 3D geometric operations, so it is useful to know a bit about them to understand how these functions can be useful to you. A couple of good pages to learn the basics of vector math:
Vectors are the building bricks of almost all 3D geometric operations, so it is useful to know a bit about them to understand how these functions can be useful to you. A couple of good pages to learn the basics of vector math:
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* http://maths-wiki.wikispaces.com/Vectors
* http://maths-wiki.wikispaces.com/Vectors
* http://darksleep.com/player/opengl_coordinate_system_and_matrix_math.html
* http://darksleep.com/player/opengl_coordinate_system_and_matrix_math.html

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{{Code|code=
<pre>
"Vector math library for FreeCAD"
"""Vector math library for FreeCAD"""


import math,FreeCAD
import math
import FreeCAD
def add(first, other):
def add(first, other):
"add(Vector,Vector) - adds two vectors"
"""add(Vector,Vector) - adds two vectors"""
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
return FreeCAD.Vector(first.x+other.x, first.y+other.y, first.z+other.z)
return FreeCAD.Vector(first.x+other.x, first.y+other.y, first.z+other.z)
def sub(first, other):
def sub(first, other):
"sub(Vector,Vector) - subtracts second vector from first one"
"""sub(Vector,Vector) - subtracts second vector from first one"""
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
return FreeCAD.Vector(first.x-other.x, first.y-other.y, first.z-other.z)
return FreeCAD.Vector(first.x-other.x, first.y-other.y, first.z-other.z)
def scale(first,scalar):
def scale(first,scalar):
"scale(Vector,Float) - scales (multiplies) a vector by a factor"
"""scale(Vector,Float) - scales (multiplies) a vector by a factor"""
if isinstance(first,FreeCAD.Vector):
if isinstance(first,FreeCAD.Vector):
return FreeCAD.Vector(first.x*scalar, first.y*scalar, first.z*scalar)
return FreeCAD.Vector(first.x*scalar, first.y*scalar, first.z*scalar)
def length(first):
def length(first):
"lengh(Vector) - gives vector length"
"""lengh(Vector) - gives vector length"""
if isinstance(first,FreeCAD.Vector):
if isinstance(first,FreeCAD.Vector):
return math.sqrt(first.x*first.x + first.y*first.y + first.z*first.z)
return math.sqrt(first.x*first.x + first.y*first.y + first.z*first.z)
def dist(first, other):
def dist(first, other):
"dist(Vector,Vector) - returns the distance between both points/vectors"
"""dist(Vector,Vector) - returns the distance between both points/vectors"""
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
return length(sub(first,other))
return length(sub(first,other))
def normalized(first):
def normalized(first):
"normalized(Vector) - returns a unit vector"
"""normalized(Vector) - returns a unit vector"""
if isinstance(first,FreeCAD.Vector):
if isinstance(first,FreeCAD.Vector):
l=length(first)
l=length(first)
return FreeCAD.Vector(first.x/l, first.y/l, first.z/l)
return FreeCAD.Vector(first.x/l, first.y/l, first.z/l)
def dotproduct(first, other):
def dotproduct(first, other):
"dotproduct(Vector,Vector) - returns the dot product of both vectors"
"""dotproduct(Vector,Vector) - returns the dot product of both vectors"""
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
return (first.x*other.x + first.y*other.y + first.z*other.z)
return (first.x*other.x + first.y*other.y + first.z*other.z)
def crossproduct(first, other=FreeCAD.Vector(0,0,1)):
def crossproduct(first, other=FreeCAD.Vector(0,0,1)):
"crossproduct(Vector,Vector) - returns the cross product of both vectors.
"""crossproduct(Vector,Vector) - returns the cross product of both vectors.
If only one is specified, cross product is made with vertical axis, thus returning its perpendicular in XY plane"
If only one is specified, cross product is made with vertical axis, thus returning its perpendicular in XY plane"""
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
return FreeCAD.Vector(first.y*other.z - first.z*other.y, first.z*other.x - first.x*other.z, first.x*other.y - first.y*other.x)
return FreeCAD.Vector(first.y*other.z - first.z*other.y, first.z*other.x - first.x*other.z, first.x*other.y - first.y*other.x)
def angle(first, other=FreeCAD.Vector(1,0,0)):
def angle(first, other=FreeCAD.Vector(1,0,0)):
"angle(Vector,Vector) - returns the angle in radians between the two vectors.
"""angle(Vector,Vector) - returns the angle in radians between the two vectors.
If only one is given, angle is between the vector and the horizontal East direction"
If only one is given, angle is between the vector and the horizontal East direction"""
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
return math.acos(dotproduct(normalized(first),normalized(other)))
return math.acos(dotproduct(normalized(first),normalized(other)))
def project(first, other):
def project(first, other):
"project(Vector,Vector): projects the first vector onto the second one"
"""project(Vector,Vector): projects the first vector onto the second one"""
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
return scale(other, dotproduct(first,other)/dotproduct(other,other))
return scale(other, dotproduct(first,other)/dotproduct(other,other))
}}
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Latest revision as of 20:24, 24 August 2021

Introduction

This is a Python module containing a couple of useful functions to manipulate vectors. This library is included in the Draft_Workbench and can be accessed like this from the Python interpreter:

import DraftVecUtils

Please note that this module was created a long time ago, when the Vector class didn't have many of its methods. Now these operations can be done by the Vector class itself.

Although the DraftVecUtils module still exists, and it is still used inside the Draft Workbench, it is probably better to use the Vector methods directly for new developments.

Functions

Vectors are the building bricks of almost all 3D geometric operations, so it is useful to know a bit about them to understand how these functions can be useful to you. A couple of good pages to learn the basics of vector math:

"""Vector math library for FreeCAD"""

import math
import FreeCAD
 
def add(first, other):
    """add(Vector,Vector) - adds two vectors"""
    if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
        return FreeCAD.Vector(first.x+other.x, first.y+other.y, first.z+other.z)
 
def sub(first, other): 
    """sub(Vector,Vector) - subtracts second vector from first one"""
    if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
        return FreeCAD.Vector(first.x-other.x, first.y-other.y, first.z-other.z)
 
def scale(first,scalar):
    """scale(Vector,Float) - scales (multiplies) a vector by a factor"""
    if isinstance(first,FreeCAD.Vector):
        return FreeCAD.Vector(first.x*scalar, first.y*scalar, first.z*scalar)
 
def length(first):
    """lengh(Vector) - gives vector length"""
    if isinstance(first,FreeCAD.Vector):
        return math.sqrt(first.x*first.x + first.y*first.y + first.z*first.z)
 
def dist(first, other):
    """dist(Vector,Vector) - returns the distance between both points/vectors"""
    if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
        return length(sub(first,other))
 
def normalized(first):
    """normalized(Vector) - returns a unit vector"""
    if isinstance(first,FreeCAD.Vector):
        l=length(first)
        return FreeCAD.Vector(first.x/l, first.y/l, first.z/l)
 
def dotproduct(first, other):
    """dotproduct(Vector,Vector) - returns the dot product of both vectors"""
    if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
        return (first.x*other.x + first.y*other.y + first.z*other.z)
 
def crossproduct(first, other=FreeCAD.Vector(0,0,1)):
    """crossproduct(Vector,Vector) - returns the cross product of both vectors. 
    If only one is specified, cross product is made with vertical axis, thus returning its perpendicular in XY plane"""
    if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
        return FreeCAD.Vector(first.y*other.z - first.z*other.y, first.z*other.x - first.x*other.z, first.x*other.y - first.y*other.x)
 
def angle(first, other=FreeCAD.Vector(1,0,0)):
    """angle(Vector,Vector) - returns the angle in radians between the two vectors. 
    If only one is given, angle is between the vector and the horizontal East direction"""
    if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
        return math.acos(dotproduct(normalized(first),normalized(other)))
 
def project(first, other):
    """project(Vector,Vector): projects the first vector onto the second one"""
    if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
        return scale(other, dotproduct(first,other)/dotproduct(other,other))