# Matrix rotation of unit cube

I have managed to get the cube to rotate about the z and x axes, by applying the appropriate matrix to a single point, then using the 'cube' tool from the drop-down menus. (CubeRz and CubeRx) but trying the same process about the y axis (b=1) the cube suddenly jumps to the wrong position for theta>180.

I could rotate 4 vertices and construct the cube, but it's a lot of commands!

I hoped I could use Applymatrix(Matrix,cube) but cube is not accepted as an object, as far as I can see.

I have also tried to use cube(...) in the input line, but keep getting an error message.

I know there is an inbuilt command, Rotate(), but my students have to know the matrix operations.

What am I doing wrong? Thx!

PS I notice my GGb 5 dates from March (although I did start this on-line) so I will try updating it!

I think you have a problem with continuity of transformation of sphere. rotate the cube is not suddenly continue

I am afraid that you must do with two points, at least because hairy ball theorem

https://en.wikipedia.org/wi...

perhaps other user can give a solution

Hello kathrynp!

I think that you can avoid this "jumping" by changing the definition of your cube.

Try

And than I presume, that this "jumping" is caused by the "internal way of GeoGebra" to create the cube by three given points, especially your point D.Take a short look at the attached file and I hope, that this will solve your problem.

Greetings

mire2

I'll try it when the bug I found in applymatrix are solved

I have done the work using the matrix product instead applymatrix over the basic points of a cube

it is not hard

Thanks for your help, everyone! I still don't know why I was getting the error above. I abandoned that file and started fresh, and all worked well. Matrix transformations in 3D are not as straightforward as in 2D! Particularly working out how to generate the transformed cube!

perhaps this post help you to find problems

https://help.geogebra.org/t...

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