M421 - Set Mesh Value

motion Set a single mesh Z height AUTO_BED_LEVELING_(BILINEAR|UBL)|MESH_BED_LEVELING

This command is used to set a single Z value for a mesh point in the stored bed leveling data.

Allowed forms are M421 In Jn Zn, M421 Xn Yn Zn (MESH_BED_LEVELING only) or M421 C Zn (AUTO_BED_LEVELING_UBL only).

M421 [C<bool>] [I<int>] [J<int>] [N<bool>] [Q<linear>] [X<linear>] [Y<linear>] [Z<linear>]

`[C<bool>]`	Set the mesh point closest to the current nozzle position (`AUTO_BED_LEVELING_UBL` only)
`[I<int>]`	X index into the mesh array
`[J<int>]`	Y index into the mesh array
`[N<bool>]`	Set the mesh point to undefined (`AUTO_BED_LEVELING_UBL` only)
`[Q<linear>]`	A value to add to the existing Z value
`[X<linear>]`	X position (which should be very close to a grid line) (`MESH_BED_LEVELING` only)
`[Y<linear>]`	Y position (which should be very close to a grid line) (`MESH_BED_LEVELING` only)
`[Z<linear>]`	The new Z value to set