Surface Assign ID

What is it for?

• Changing only metal areas to core:metal
• Assigning different face IDs to floors, walls, and roofs after creation
• Creating custom regions that Surface ID Mask can extract

Overview

Paints material or face IDs onto white areas of a mask. It does not change the visible appearance; it writes information such as “this is metal” or “this is the left wall” into the Surface. Downstream lighting, material-specific processing, and extraction with surface_id_mask can then use that information.

Usage tips

• It forms a round trip with surface_id_mask: paint a region with Assign, then extract it later with Mask. This enables custom divisions where regions you paint drive your own processing.
• Face IDs such as wall:left enable direction-specific shading and outline control. Review the divisions with the F view in the Surface preview.
• If you need to paint only material IDs, the dedicated surface_assign_material provides the same operation.

Related nodes

• surface_id_mask — extracts a painted ID

• surface_assign_material — material-ID-only version

• path_mask / mask_boolean — create the mask that defines the painted area

• surface_light_preview — reviews the effect of IDs

• Version: 1

Examples

[Surface] → surface → [Surface Assign ID(id_kind:Face, face_id:wall:left)] → surface
              [Mask] → mask

After painting the face ID, use the F Surface preview to see the painted face in a separate color.