What?
Wait, your face!
Wait!
Let me see your face!
-- Donald Curtis

Previously:

What's next?

Needless to say, let's try the third cubie that has both red and pink. Geometrically speaking, a face is shared by only two cells. In other words, there should be exactly 4 cubies that have both red and pink.

Yeah, we can find one at Y+O6. Its pink is at Z-O6. Its another sticker is yellow at X-O6, but the final one is hidden at W+. That's fine though. By the existence of yellow sticker, we know that the right place for this cubie is W-O5.

It it not too tricky as well. It would be ideal if the red is at the Y+ direction cell of the pink. Now the pink is at Z-, so we need a clockwise X-axis-twist. It is convenient that a X-axis-twist to Y+ does not affect the two cubies at W-, so let's do it:

Check the yellow, pink and red. We are getting closer!

Let's finish a face!

From W-O3/X+O2, we know the 4th cubie to complete our first face has a blue sticker. From W-O5/Z-O2, we know it has an orange. Of course it has read and pink. So where is this cubie?

Other than the 3 reds in W-, we see other 4 reds, so the rest one must be at W+ that we cannot see. First let's check the X+O5. It has red-blue-orange-turquoise, no pink. We can locate the position it should be is W-O7, because orange/blue means it is near Z-/X+ respectively, but it cannot be W-O4 otherwise it must has pink.

One checked. We check X+O3 for the next. It has blue and orange, and the 4th sticker at W+ that we cannot see for now. Sure we can center X+ to see its hidden color, be simple deduction can tell us this is luckily the cubie we are looking for. Because it has both orange and blue, which means it has to be near Z-/X+. There is only two cubies with a red sticker can meet these conditions, and one of them has been confirmed, so this X+O3 must be the cubie we are looking for.

Now it is getting trickier. I don't know if there is any, but I cannot find a easy way to simply put X+O3 back to W-O4.

We can still do some analysis first. If we apply a Z-axis-twist clockwisely to X+, X+O3's pink should goes to Y-, which is a ideal position: as long as the orientation of two stickers are fixed, the cubie has a correct orientation. But such a twist affects W-, ruining our W-O3.

So the plan is like this: we move the W-'s Y- face elsewhere, so that the mentioned twist won't affect them, and then resume W-. Then, we move W-'s X- face elsewhere, so that we can move the 4th cubie to W-O4. Then we resume W-'s X-face, and it should be done.

It's always challenging to figure out a setup that works, so I pause here for a while. Then I find that changing an approach can be better. Simply put, I plan a setup that the two vertical adjacent cubies Y-axis-twist to the W-'s Z+ face, then join the 4th to the lonely one, then resume them all altogether. As follows,

Conclusion

Yeah, we now successfully re-arrange 4 cubies that forms a face! This is satisfying, and I can't wait to go next. Maybe it will be a setup twist hell, but that will be fun as well.

小結

完成了 2x2x2x2 的第一個面。