Subdivision Levels

Subdivision Levels (Multiresolution)

Multiresolution sculpting is one of the most powerful workflows in digital art. It allows you to freely move back and forth between low-polygon basemeshes (for gross proportional adjustments) and multi-million-polygon high-resolution detail (for skin pores, wrinkles, and fabric weaves).

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Why Multiresolution?

When sculpting on a single dense mesh (e.g. 5 million polygons), making large structural changes—like lengthening an arm or reshaping a jawline—is difficult and prone to surface lumpiness.

Multiresolution solves this by maintaining a hierarchy of subdivision levels:

1. Step down to Level 1 (Shift + D): Move a few hundred base vertices with the Grab brush to change global anatomy or silhouette.
2. Step back up to Level 5 (D): All high-frequency surface pores, veins, and fine wrinkles automatically update their positions while preserving their local detail displacements!

+--------------------------------------------------------------+
| [Level 1] ~2,000 tris  --> Silhouette & Proportions          |
|    |                                                         |
| [Level 2] ~8,000 tris  --> Primary Muscle Masses             |
|    |                                                         |
| [Level 3] ~32,000 tris --> Secondary Features (Eyes, Lips)   |
|    |                                                         |
| [Level 4] ~128,000 tris -> Tertiary Folds & Creases          |
|    |                                                         |
| [Level 5] ~512,000 tris -> Skin Pores & Micro-detailing      |
+--------------------------------------------------------------+

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Multiresolution Controls

The multiresolution controls are located in the top bar and in the Multires tab of the right sidebar:

Action	Shortcut	Description
Step Down	Shift + D	Switches viewport display and active sculpting to the next lower subdivision level.
Step Up	D	Switches viewport display and active sculpting to the next higher subdivision level.
Subdivide	Ctrl + D	Adds a new subdivision level to the top of the stack, quadrupling polygon density.
Delete Higher	Button in panel	Discards all levels above the current level to permanently reduce file size.
Delete Lower	Button in panel	Makes the current subdivision level the new permanent base mesh (useful before baking).

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Polygon Density vs Memory Table

Each Catmull-Clark / Loop subdivision quadruples the number of polygons:

Level	Quad Faces	Approx. Vertices	Typical Sculpting Phase
Base (0)	1,000	1,002	Clean topology, UV unwrapped base
Level 1	4,000	4,002	Proportions, limb angles, broad silhouettes
Level 2	16,000	16,002	Muscle groups, facial landmarks, ear shapes
Level 3	64,000	64,002	Eyelids, lip contours, fingernails, knuckles
Level 4	256,000	256,002	Wrinkles, tendon definition, scars, seams
Level 5	1,024,000	1,024,002	Micro-pores, iris details, fingerprint ridges
Level 6	4,096,000	4,096,002	High-density scan detail & complex alphas

Tip

The Golden Rule of Multiresolution Sculpting: Never step up to the next subdivision level until you have extracted 100% of the form possible at your current level. Jumping to Level 5 too early leads to lumpy, uncontrolled surfaces.

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Detail Propagation & Sculpting Across Levels

• When you sculpt on Level 1, displacements recorded on Levels 2 through 5 are treated as local vector offsets anchored to the base surface normal.
• When you smooth on Level 1, high-frequency noise from higher levels is preserved while the underlying curvature is relaxed.
• When you smooth on Level 5, you erase only the fine surface detail, leaving base anatomy completely untouched.

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Reconstructing Subdivision Levels

If you import an external base mesh that was subdivided in another tool (e.g. ZBrush or Blender) without the original multires levels:

1. Load the dense mesh.
2. In the Multires panel, click Reconstruct Lower Levels.
3. OxyBrush will algorithmically detect the subdivision grid pattern and recreate Levels 1, 2, and 3 beneath the dense mesh, restoring your ability to step down!