85 lines
4.5 KiB
HTML
85 lines
4.5 KiB
HTML
<html><head><title>FreeCAD vector math library</title><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><link type='text/css' href='wiki.css' rel='stylesheet'></head><body><h1>FreeCAD vector math library</h1></div>
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<div id="mw-content-text" lang="en" dir="ltr" class="mw-content-ltr"><div class="mw-parser-output"><p>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 <a href="Draft_Module.html" title="Draft Module">Draft Module</a> and can be accessed like this from the python interpreter:
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</p>
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<pre>import DraftVecUtils
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</pre>
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<p>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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</p>
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<ul><li> <a rel="nofollow" class="external free" href="http://en.wikipedia.org/wiki/Vector_space">http://en.wikipedia.org/wiki/Vector_space</a></li>
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<li> <a rel="nofollow" class="external free" href="http://maths-wiki.wikispaces.com/Vectors">http://maths-wiki.wikispaces.com/Vectors</a></li>
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<li> <a rel="nofollow" class="external free" href="http://darksleep.com/player/opengl_coordinate_system_and_matrix_math.html">http://darksleep.com/player/opengl_coordinate_system_and_matrix_math.html</a></li></ul>
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<pre>
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"Vector math library for FreeCAD"
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import math,FreeCAD
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def add(first, other):
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"add(Vector,Vector) - adds two vectors"
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if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
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return FreeCAD.Vector(first.x+other.x, first.y+other.y, first.z+other.z)
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def sub(first, other):
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"sub(Vector,Vector) - subtracts second vector from first one"
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if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
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return FreeCAD.Vector(first.x-other.x, first.y-other.y, first.z-other.z)
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def scale(first,scalar):
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"scale(Vector,Float) - scales (multiplies) a vector by a factor"
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if isinstance(first,FreeCAD.Vector):
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return FreeCAD.Vector(first.x*scalar, first.y*scalar, first.z*scalar)
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def length(first):
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"lengh(Vector) - gives vector length"
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if isinstance(first,FreeCAD.Vector):
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return math.sqrt(first.x*first.x + first.y*first.y + first.z*first.z)
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def dist(first, other):
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"dist(Vector,Vector) - returns the distance between both points/vectors"
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if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
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return length(sub(first,other))
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def normalized(first):
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"normalized(Vector) - returns a unit vector"
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if isinstance(first,FreeCAD.Vector):
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l=length(first)
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return FreeCAD.Vector(first.x/l, first.y/l, first.z/l)
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def dotproduct(first, other):
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"dotproduct(Vector,Vector) - returns the dot product of both vectors"
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if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
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return (first.x*other.x + first.y*other.y + first.z*other.z)
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def crossproduct(first, other=FreeCAD.Vector(0,0,1)):
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"crossproduct(Vector,Vector) - returns the cross product of both vectors.
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If only one is specified, cross product is made with vertical axis, thus returning its perpendicular in XY plane"
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if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
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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)
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def angle(first, other=FreeCAD.Vector(1,0,0)):
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"angle(Vector,Vector) - returns the angle in radians between the two vectors.
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If only one is given, angle is between the vector and the horizontal East direction"
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if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
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return math.acos(dotproduct(normalized(first),normalized(other)))
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def project(first, other):
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"project(Vector,Vector): projects the first vector onto the second one"
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if isinstance(first,FreeCAD.Vector) and isinstance(other,FreeCAD.Vector):
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return scale(other, dotproduct(first,other)/dotproduct(other,other))
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</pre>
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<div style="clear:both"></div>
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</div>
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</div>
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</div><div class="printfooter">
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Online version: "<a dir="ltr" href="https://www.freecadweb.org/wiki/index.php?title=FreeCAD_vector_math_library&oldid=235986">http://www.freecadweb.org/wiki/index.php?title=FreeCAD_vector_math_library&oldid=235986</a>"</div>
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