# mobile point in cube

Rumburak shared this question 5 years ago

How do I create a mobile point in an cube not only on edges ?

Hi,

with GGBscript :

in script OnUpDate of P : SetValue[...]

...

1

Make three sliders r, s, t with values from 0 to 1.

If your cube is ABCDEFGH, then all possible combinations of r, s and t give you all possible points inside the cube (or at its surface) with

1. A+r*(B-A)+s*(D-A)+t*(E-A)

1

Yes, but I want to move this point with mouse anywere INSIDE cube.

For now my point move on edges and all diagonals of cube. But it's not enough...

1

His idea should work ... may be have integer sliders? Use steps like 0.01

1

Okay ... I tried that but I can't move the point!? Only if I use the sliders.

2

Without sliders: Use the command

PointIn[ <Region> ]

to create a point in ABCD.

Construct a perpendicular line to ABCD through this point.

This line has intersections with ABCD and EFGH. Make a segment between the intersction points.

Make a point in this segment.

1

In this case the point can be moved only in this segment...

1

i think he wants a point in the faces of cube

1

No, INSIDE . Like the water inside a cube.

1

then use the abakus method

you can move the last point in the segment and the base point of segemnt inside the base of cube

1

Maybe I'm not explicit. I do not want to move point somewhere. I want to move it anywhere inside the cube.

1

this is the best I can do without scripts

move the red point then the green point, repeat the action

Files: foro.ggb
1

This is the best I can do.

Point P move on cube diagonals

Point N move on face diagonals

Point Q move on perpeniculars to "centre" of faces.

and this is not evrywere...

Maybe in other version of Geogebra ...

Files: cube.jpg
1

Yes, yours and Abakus solution is a surrogate for now. In the absence of something else is a reasonable idea. Thanks mathmagic & abakus .

2

Hi,

with GGBscript :

in script OnUpDate of P : SetValue[...]

...

1

[FR] Oui, votre solution Patrick Clément est exceptionnelle. Il ressemble un peu à des précédents, mais il est un corollaire de tous.

Je vous remercie beaucoup.

[EN] Yes, your solution Patrick Clément is exceptional. It somewhat resembles with previous ones but it is a corollary of all.

Thank you very much.