Sculpting damage and wear

Sculpted damage is the breaks, chips, cracks, dents and erosion you add to an otherwise intact form. It makes stone look old, brick look abused and a place look lived in, and it is one of the main tools of environmental storytelling. It is also one of the easiest things to overdo.

This guide first covers where the damage should be stored, because that choice matters more than the brushes.

#1. Decide where the damage is stored

The deciding factors are memory and reuse. On The Last of Us Part I, Matthew Trevelyan Johns found texture memory consumed by many small, uniquely baked props, and built a trim pipeline to replace them; he estimates about 80% of his Lab assets used baked-bevel trims instead of unique bakes (ArtStation: The Last of Us: Part I...Trim Pipeline). Unique damage is the most expressive option and the most expensive.

#2. Start from a clean, finished form

Damage is a change to a form, so the form has to exist first. Model or sculpt the intact version, make sure its primary and secondary forms are right, and keep a copy. Khafizov blocked out his ruin in Maya or Blender, split the modular pieces from the blockout, and only then sculpted in ZBrush (80 Level: How to Make Atmospheric Stylized Modular…).

Keeping the clean version lets you make several damage variants from one base and lets you return to it when an art director asks for "less broken".

#3. Large breaks

Big breaks remove volume. They are closest to booleans:

• Blender: Box Trim performs "a Boolean operation via a box gesture" (Blender 3.6 Manual: Toolbar).
• ZBrush: with DynaMesh you can "merge pieces, or remove geometry, similar to Boolean operations" (maxon.net: Base Mesh Creation). Each remesh with Project on loses a little detail, so make big breaks before fine detail (ZBrush for iPad Help: Tool palette: Geometry > DynaMesh).
• Variety from Booleans: Sobotta notes that Booleans or merging pieces add variety to rock chunks (ArtStation: Rock Breakdown).

Where broken geometry meets a textured surface, plan the join. Khafizov developed his brick material alongside the brick geometry because his scene had "many broken fragments", and needed "a smooth transition between the texture and real geometry in areas of broken brickwork" (80 Level: How to Make Atmospheric Stylized Modular…).

#4. Chips and broken edges

Chips are small fracture planes on edges and corners. Cut them as planes, not as soft dents:

• Blender: Multi-plane Scrape "scrapes the mesh with two angled planes at the same time, producing a sharp edge between them"; Scrape flattens; Pinch is "useful for polishing angles and creases" (Blender 3.6 Manual: Toolbar).
• ZBrush: JaviSkau cuts planes and breakage with TrimSmoothBorder (ArtStation: Rock Sculpting Workflow in ZBrush | 3-Step…); Zlobin's stone silhouettes use TrimSmoothBorder, Planar and Trim brushes (80 Level: Creating a Stone Wall Material in ZBrush…).

Vary chip size, and cluster chips rather than spacing them evenly. Leave some edges almost intact so the damaged ones read.

#5. Cracks

Cracks are the classic tertiary detail. Draw them with a sharp brush, then tighten them:

• Blender: Draw Sharp has "a much sharper Falloff. Useful for creating creases and sharp angles"; Crease is "useful for creating and polishing sharp creases" (Blender 3.6 Manual: Toolbar).
• Alphas: Zlobin adds cracks and damage with crack and damage alphas, balancing detail against the surrounding areas (80 Level: Creating a Stone Wall Material in ZBrush…). Sobotta's rock material sculpts combine hand sculpting and alphas (ArtStation: Rock Breakdown).
• Mortar and grout: Zlobin uses Clay BuildUp and FractureB for a noisy, dry mortar look (80 Level: Creating a Stone Wall Material in ZBrush…).

A crack should start somewhere believable, such as a corner, an edge or a point of impact, and thin out as it runs.

#6. Wear and erosion

Wear is the opposite of a break: it softens. Blender's Smooth brush "smooths out irregularities in the surface and shrinks volumes" (Blender 3.6 Manual: Toolbar), which is a quick way to round worn steps and weathered edges. Sobotta's rock set includes a smooth, eroded rock material with subtle undulation (ArtStation: Rock Breakdown).

Combine soft wear on exposed, handled surfaces with sharp breaks in places that took impacts. A worn stair with crisp chips on its nosing shows two different kinds of history, and the contrast helps both read. See edge wear for wear in textures.

#7. Bake and blend

Bake damage like any other high poly (see baking and the high-to-low workflow). Then decide how texturing will follow it: cavity and curvature maps from the bake drive dirt into cracks and highlight chipped edges. See smart materials.

For tileable damage, give level artists a way to place it: vertex-paint channels, as on Sobotta's dam walls (ArtStation: Brick and Concrete Generator), or height blending between clean and damaged materials.

#Further reading and watching