Similarities and Differences between a Rubik’s Cube and a Meffert’s Master Pyramorphinx
Cube is a cube; MP is a tetrahedron that can morph into various shapes.
Cube has 6 centers; MP has 6 edges. Cube centers have 1 color each so orientation does not matter; MP edges have 2 colors each and can be oriented 4 ways. Cube centers are both centers of rotation and centers of faces; MP edges are the centers of rotation for the layers although they are edges between faces.
Cube has 12 edges; MP has 12 trapezoids. Cube edges have 2 colors each so orientation matters; MP trapezoids are trapezoids so orientation matters. Cube edges are unique, so they can be double-swapped, or 3-cycled, but no single pair can be swapped; MP trapezoids are not unique, so can not only be double-swapped and 3-cycled, but can appear to have 2 swapped. In reality 2 of one color and 1 of another need to 3-cycle.
Cube has 8 corners; MP has 4 corners and 4 centers (the triangles). Cube corners have 3 colors each so orientation matters; MP corners have 3 colors each so orientation matters; MP center triangles have 1 color each and are equilateral so orientation does not matter. On a cube you cannot have 1 twisted corner, but on a MP you can. On a cube if you have 2 twisted corners they are twisted in opposite directions, but on a MP 2 corners can be twisted in the same direction.
Cube has 6 sides; MP has 4 sides
Cube has 54 stickers; MP has 40 stickers
Cube has 3 layers top to bottom, left to right, and front to back; so does the MP, it just isn’t as obvious since it isn’t cube-shaped.
Cube can be solved using a variety of strategies; MP can be solved using the same basic strategies as solving a cube, with the added orientation challenges mentioned above.
Strategy—Like Solving a Cube Using F2L/LL
Get two orange trapezoids and two blue trapezoids correctly situated on the blue-orange edge.
Get the other blue and orange edges situated correctly above the four trapezoids placed in step 1.
Get a blue-orange corner along with the trapezoid that goes above it. Get the other corner-trapezoid pair too.
Get the blue triangle and the last blue trapezoid. Get the orange ones too. At this point the First 2 Layers are done. The bottom layer is the one with the blue-orange edge, the two corners that have blue-orange on them, two blue trapezoids and two orange trapezoids, the blue triangle, and the orange triangle. That is 9 pieces. Same as the number of pieces on the white layer of a Rubik’s Cube.
The middle layer of the Master Pyramorphinx consists of four edges and four trapezoids. 8 pieces, just like the middle layer of a Rubik’s Cube.
Twist the last layer so the yellow-green edge is oriented correctly.
3-Cycle the corners/triangles into place. This may only take one 3-Cycle, or it might take two.
If necessary, twist two corners, or twist a corner and two triangles. There are a couple ways to go about this. The twist two way, and the RURiURU2RiU2 way.
3-Cycle the yellow and green trapezoids. Sometimes it appears that two need to swap, but this can’t be done. Do a 3-Cycle that will accomplish the desired result.
If necessary, flip the trapezoids so they fit correctly in their places.