Homogeneous Coordinates in 3d

tush shared this question 1 month ago
Answered

GeoGebra has a "built in" homogeneous coordinates usage inside the ApplyMatrix command: mapping point (x, y, z) to (x/z, y/z)

Can we do the same on a 3d point in space by multiplying it with a 4x4 matrix? i.e.

to map

(x, y, z, k) to (x/k, y/k, z/k).


I am working with 4x4 matrices in perspective projection and I am missing this ability.

Comments (2)

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I have made some experiments.

maybe you take a look at this

https://www.geogebra.org/m/...

photo
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pienso que GG no maneja coordenadas homogeneas en 3D. el puede hacer applymatrix() con matrices 3x3 lo que da una transformacion vectorial. para aplicar una matriz {{1,2,,3,4},{2,2,2,5},{3,3,3,6},{0,0,0,1}} yo hago applymatrix({{1,2,,3},{2,2,2},{3,3,3}}) y luego la traslacion (4,5,6)

NOTA: (x, y, z, k) to (x/k, y/k, z/k) no es una transformacion matricial

te aconsejo crear una herramienta personal

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