Code

3dsmax – Unwrap UVW and MaterialID

By telleropnul, June 22, 2016

Multi/Sub material texturing of an already unwrapped character model with only matID 1 set

UnwrapUVW:
Very easy to make polygon selections using seams.
Can’t change matIDs here; matIDs should already be in place.

Editable Poly Sub Object mode:
Very easy to change matIDs.
Can’t make polygon selections using seams.

Solution:
Suppose our skinned character model is just an Editable Mesh object in the modifier stack (with proper UV coordinates and seams).

  1. Add an UnwrapUVW modifier to the stack.
  2. From inside the UnwrapUVW modifier, select a polygon and ‘Expand Polygon Selection to Seams’.
  3. Now add an Edit Mesh modifier to the stack.
  4. Go into Sub-Object mode (Polygon).
  5. You should notice the UnwrapUVW polygon selection is preserved up the stack. You can now change the matID for your selection using the Edit Mesh modifier rollout.
  6. Make sure to exit Sub-Object mode for all modifiers on the stack when done. This is to ensure no Sub-Object polygon selection is active prior to the next step.
  7. Select the Edit Mesh modifier and select ‘Collapse To’.

You are left with an Editable Mesh object with a different matID applied to part of the mesh (perfectly matching the UV seams) ready for a Multi/Sub material.

You can repeat step 1 to 7 to assign additional matIDs to different parts of the mesh.

Notes:

  • If you skip step 6 you will lose UV coordinates and UV seams.
  • You have to collapse the mesh each time to save your changes to the mesh. If you only repeat steps 2 to 5 instead of 1 to 7 you will lose your changes; without collapsing your previous changes are lost.
  • There is no need to open the UV editor inside the UnwrapUVW modifier.

When using the UV editor in the UnwrapUVW modifier there is a button at the bottom right corner “Display Only Selected Polygons”.  When you right click a mesh, there is “Unhide all” and “Hide Selected”.  I would have expected an option “Hide Unselected” or similar here rather than a separate button.

MaterialIDs are for assigning different bitmaps / materials to different parts of your mesh i.e. hair (procedural), body (unwrap), face (planar or sphere mapping), etc.  Typically used in combination with Multi/sub material.  Often used for unwrapped (game character) models using UV coordinate maps and seams.

MapID/mappingID is for layering textures i.e. a (seamless tile) brick wall texture for an entire wall with separate textures on top for added detail (graffiti, damaged plaster, etc.)