@Changchung ,
Your preview doesn’t look very uniform, but I can’t tell if it actually looks that way in the picture you used to map. It should be mostly OK for patterns even if it’s a little off.
If you post the image you used to map, and the text of your pixel map coordinates, any of us can put these into the pixel mapper tool and help troubleshoot the map itself.
Pixelblaze V2 didn’t ship with many patterns that used render2D
and could take advantage of the pixel map. Give it a try with “cube fire”, or some of the 2D patterns from the pattern site. Very old 2D patterns calculated the coordinates via pattern code, and assumed regular matrix configurations so won’t work with your sign. Look for “render2D” in the code.