Mask Selection
선택을 가르는 수업
Intro
Select only what the scene needs — gate extrusions, scatter zones, and material regions with field-driven masks.
Why It Matters
Mask is the grammar of focus. In Blender it is Compare and Delete Geometry; in Photoshop it is layer masks; in Premiere it is track mattes. The atlas always needs to show some faces and hide others.
Leaf Meaning
Gate extrusions, scatter, and material zones — show only the faces and points the atlas needs.
Blender Examples
- Compare + Index — extrude only every second face on a city grid.
- Switch node — route geometry based on a boolean field.
- Delete Geometry — remove unselected points after a Compare pass.
Cross-Tool Examples
| Tool | Example |
|---|---|
| Blender | Compare + Switch + Delete Geometry — field-driven selection. |
| Photoshop | Layer masks, clipping masks, and channel selections. |
| Premiere | Opacity masks and track mattes on video layers. |
| After Effects | Mask paths, track mattes, and roto shapes. |
| Houdini | Group SOP and blast selections by attribute. |
| Atlas Logos | Face-domain masks for terrain zones and district labels. |
Atlas Logos Use
Mask extrusion faces for ancient city districts, hide terrain below water level, and isolate Galilee shoreline zones for scatter.
Related Projects
Practice Task
Use Compare + Index to extrude only every second face on a grid, then Delete Geometry on the rest.
Open guided practice → Checklist
- Build a face grid with consistent topology
- Wire Compare so selection responds to Index or position
- Extrude only the masked faces
- Delete or Separate the unselected geometry
- Document the mask rule in a Frame label