Transformations in the geom3d Package
Description
Examples
The help page geom3d[transformation] describes the transformations that can be applied directly to a specific geometric object.
In general, to define a transformation without specifying the object to which the transformation is to be applied, use the ``verb'' form of the above transformations.
rotation
rotate
translation
translate
ScrewDisplacement
ScrewDisplace
reflection
reflect
RotatoryReflection
RotatoryReflect
GlideReflection
GlideReflect
homothety
dilate
homology
StretchRotate
Using the function geom3d[inverse], one can compute the inverse of a given product of transformations, the function geom3d[transprod] converts a given transformation or product of transformations into a product of three ``primitive'' transformations (translate, rotate, and dilate), while the function geom3d[transform] is to apply the ``result'' transformation to a specific geometric object.
with⁡geom3d:
Define t1 which is a homothety with ratio 3, center of homothety (0,0,0)
t1≔dilate⁡3,point⁡o,0,0,0
t1≔dilate⁡3,o
Define the plane oxy
point⁡A,1,0,0,point⁡B,0,0,1:
line⁡l1,o,A,line⁡l2,o,B,plane⁡p,l1,l2:
dsegment⁡AB,A,B:
Define t2 which is a glide-reflection with p as the plane of reflection and AB as the vector of translation
t2≔GlideReflect⁡p,AB
Define t3 as a screw-displacement with l3 as the rotational axis and AB as a vector of translation
t3≔ScrewDisplace⁡π2,line⁡l3,A,B,AB
t3≔ScrewDisplace⁡π2,l3,AB
Compute q1 which is the product of t2t1⁢t3
q1≔transprod⁡t2t1,t3
q1≔transprod⁡dilate⁡13,o,reflect⁡p,translate⁡AB,dilate⁡3,o,rotate⁡π2,l3,translate⁡AB
Compute the inverse of q1
q2≔inverse⁡q1
q2≔transprod⁡translate⁡_AB,rotate⁡3⁢π2,l3,dilate⁡13,o,translate⁡_AB,reflect⁡p,dilate⁡3,o
Compute the product of q1⁢q2; one can quickly recognize that this is an identity transformation
q≔transprod⁡q1,q2
q≔transprod⁡dilate⁡13,o,reflect⁡p,translate⁡AB,dilate⁡3,o,rotate⁡π2,l3,translate⁡AB,translate⁡_AB,rotate⁡3⁢π2,l3,dilate⁡13,o,translate⁡_AB,reflect⁡p,dilate⁡3,o
Simple check
tetrahedron⁡te,o,1
te
transform⁡te1,te,q
te1
AreDistinct⁡te,te1
false
Hence, the two objects are the same
See Also
geom3d[draw]
geom3d[objects]
geom3d[transformation]
Download Help Document
What kind of issue would you like to report? (Optional)