Offsetting entire matrix

[Rattykins]

Hopefully the visual aid helps.

So I have a rectangular cuboid across which I’ve “folded” a serpentine LED matrix. The image basically shows the box unfolded, with the serpentine LED matrix in red. Each face (front, left, back, right) is a 5 x 14 matrix with 70 leds.

I started wiring on the front, which unfortunately puts the center of the matrix at the blue circle in the top image. For the purposes of alot of matrix effects, it isn’t ideal. Octopus (I think its called) ends up centering there, which unfortunately is basically nearly on the back of the lamp.

So what I want to do is offset the whole matrix, pulling the starting pixel from 0 (lower left hand corner of the front face) back to somewhere in the middle of the back face. That would move the matrix center to the middle of the front face (the blue dot on the second diagram.

I tried mapping, but every time I did so (I believe correctly) the matrix effects would refuse to run (though solid and 1d effects behaved normally).

Am I messing up the mapping? Is there another way to do this?

Thanks!

[ALDIY]

Not sure if this is what you are after ( i have not yet tried to mess with this using ledmaps ) but beside the sliders for Octopus effects which will change the center the same way , you could try with adding offset in the 2D page , but that will change your virtual matrix size so some effects might not be good and peek may not show correct result . If i read right you want the whole center to shift to left but what happens to the panels marked BK and RT , what is the expected effect on that if not what is shown