Hi Phil,
What SlicerPro does is a parallel projection of the pattern on the former in chosen direction (here Z). The former should contain the 16 front quads of the face and forhead of the blank head that will receive the pattern. This pattern must cover all the projected surface area. All empty areas in the pattern will be missind in the result. The pattern may be larger than the projected former, but quality of the result will be lower: whenever possible, you should use vertices of projected former.
Here attached a former that should work for your project (obtained from regular 3626b head, primitives inlined with LDDP, useless areas removed with MLCad). By projection using LPC, I obtained head_former_proj.txt (this is actually a .lpc file, I changed the extension to be able to attach it here), this area should be covered exactly with your pattern. Problem, once you have created a new pattern triangle, LPC doesn't let you select it again, it will instead select the "background triangle". To avoid this, go to triangle mode, select everything and delete: only the vertices will remain (head_former_proj_vertices.txt). Build your pattern from that.
As for SlicerPro usage, options to use are -z (we project in z direction), -c (copy condlines from former). Depending on the results you may try to increase precision value progressively up to 0.05 to get rid of too small triangles (but going too far will distort shape and pattern, experiment with high values to get a feel of the nasty effects).
What SlicerPro does is a parallel projection of the pattern on the former in chosen direction (here Z). The former should contain the 16 front quads of the face and forhead of the blank head that will receive the pattern. This pattern must cover all the projected surface area. All empty areas in the pattern will be missind in the result. The pattern may be larger than the projected former, but quality of the result will be lower: whenever possible, you should use vertices of projected former.
Here attached a former that should work for your project (obtained from regular 3626b head, primitives inlined with LDDP, useless areas removed with MLCad). By projection using LPC, I obtained head_former_proj.txt (this is actually a .lpc file, I changed the extension to be able to attach it here), this area should be covered exactly with your pattern. Problem, once you have created a new pattern triangle, LPC doesn't let you select it again, it will instead select the "background triangle". To avoid this, go to triangle mode, select everything and delete: only the vertices will remain (head_former_proj_vertices.txt). Build your pattern from that.
As for SlicerPro usage, options to use are -z (we project in z direction), -c (copy condlines from former). Depending on the results you may try to increase precision value progressively up to 0.05 to get rid of too small triangles (but going too far will distort shape and pattern, experiment with high values to get a feel of the nasty effects).