# Message #1899

From: Nan Ma <mananself@gmail.com>

Subject: Re: [MC4D] Re: yet more new puzzles and a prize

Date: Mon, 07 Nov 2011 00:56:39 -0800

Hi Roice,

About the Klein quartic, I’m curious if the vertex turning and edge turning

{7,3} can be made. They have less colors than the {3,7} counterparts. So it

should be easier to find pieces on them. Thanks.

Nan

On Sun, Nov 6, 2011 at 4:42 PM, Roice Nelson <roice3@gmail.com> wrote:

> **

>

>

> No worries at all - I had just wanted to let you know rotation was

> available.

>

> It looks like Don has hardcoded the motion model (which he did

> independently of the hyperbolic geometry model), and not provided a key

> toggle to switch it. My apologies for not mentioning that earlier. To see

> the other models, you’d need to recompile his applet after altering the

> code. In the version I have downloaded, the code is around line 1374 of

> the file HyperbolicApplet.prejava file, and looks like this:

>

> //int motionModel = TRACKBALL;

> //int motionModel = DRAG_GEODESIC;

> //int motionModel = DRAG_NONPRECESSING;

> int motionModel = DRAG_PURETRANSLATE_CLAMPED;

>

> You could change what is commented to try the other models. Getting a

> setup to recompile would probably take some effort though.

>

> With regards to hyperbolic geometry models, I’ve played with a few of

> these in MagicTile, but I haven’t yet made the controls work for them. I

> just uploaded a couple pictures… some puzzles in the Klein model, and one

> pasted on the pseudosphere <http://en.wikipedia.org/wiki/Pseudosphere>.

> The Klein model may become my favorite view when solving puzzles. It has

> a very spherical feel to it, due to circles getting squashed towards the

> edges, and magnifies pieces near the center. I don’t think the

> pseudosphere ends up being a very workable view, since you can’t show a

> large percentage of the hyperbolic plane on it at once.

>

> http://groups.yahoo.com/group/4D_Cubing/photos/album/1694853720/pic/list

>

> seeya,

> Roice

>

>

> On Sat, Nov 5, 2011 at 4:38 PM, schuma <mananself@gmail.com> wrote:

>

>> Sorry for not noticing the middle mouse drag function.

>>

>> In Don’s applet I don’t know how to change to another motion model.

>> Poincare model/Klein model behave in the same way. I’m not surprised by

>> anti-procession because rolling a ball is anti-procession. Since sphere and

>> hyperbolic plane are opposite, it’s natural to see procession in the

>> hyperbolic plane. But I don’t know how to see anti-procession in hyperbolic.

>>

>> Nan

>>

>> — In 4D_Cubing@yahoogroups.com, Roice Nelson <roice3@…> wrote:

>> >

>> > Middle-mouse drag will do a rotation for you (or on a laptop, left+right

>> > drag at the same time).

>> >

>> > I find the noncommutative panning in spherical/hyperbolic spaces really

>> > neat too (doesn’t happen for Euclidean space, so middle-mouse control is

>> > required there). The code for Don’s hyperbolic tesselations

>> > applet<http://www.plunk.org/~hatch/HyperbolicApplet/>was super helpful

>> > in understanding and implementing this. Internally, you

>> > can see he played with a few different motion models, some of which

>> > anti-precess rather than precess! That is, dragging clockwise results

>> in a

>> > counterclockwise rotation of the space. I found that I liked the one he

>> > settled on for his applet the best too, though it’d be nice to add in

>> some

>> > of the others as an option.

>> >

>> > seeya,

>> > Roice

>>

>

>