Procedural Destruction Masks Using Distance Fields

Procedural destruction masks created with distance fields allow game developers to generate dynamic, stylized surface damage without relying on unique baked textures. This workflow leverages Mesh Distance Fields (MDF) or Global Distance Fields (GDF) to calculate spatial proximity between intersecting damage geometry and target assets. By combining these distance gradients with stylized noise, step functions, and material layering, developers can produce clean edge chips, peeling paint, and impact craters efficiently at runtime.

Step 1: Enable and Configure Distance Fields

Enable Mesh Distance Fields within your project settings. Ensure the target static meshes have accurate distance field representations generated:

  • Set appropriate Distance Field Resolution Scale per asset to balance visual fidelity and memory.
  • Verify the generation under visualizer modes to ensure solid interior fields without major artifacting or leaking.

Step 2: Sample Proximity in the Material

To detect where damage occurs, access distance data within the surface material graph:

  • In Unreal Engine, utilize the DistanceToNearestSurface node (or equivalent SDF sampling functions in custom HLSL/Unity shaders).
  • Subtract the surface world position from the nearest field position to retrieve a scalar value representing distance to surrounding collision or damage meshes.
  • Normalize the raw distance values using a Divide and Saturate node chain to create a controllable 0-to-1 gradient transition zone around contact points.

Step 3: Stylize the Mask with Step Thresholds

Stylized aesthetics require hard edges, stepped bands, or cartoon-like transitions rather than soft, realistic gradients:

  • Use a Smoothstep or Step function on the normalized gradient to establish a distinct damage border.
  • Introduce multiple stepped bands by chaining conditional or threshold logic to create layered effects, such as an outer chipped paint layer, an intermediate primer layer, and an exposed raw inner material (such as stone or metal).

Step 4: Break Up Uniformity with Stylized Noise

Pure distance fields create perfectly smooth, circular gradients that look unnatural. Inject stylized noise to distort the mask edges:

  • Sample a tiling stylized texture (such as Voronoi, directional brush strokes, or Worley noise).
  • Add the noise output to the distance field gradient before passing it into the step threshold.
  • Scale and clamp the noise distortion to maintain the general shape of the impact while providing sharp, hand-crafted geometric chipping along the mask perimeter.

Step 5: Drive Material Properties

Use the final packed mask to blend surface visual attributes:

  • Base Color: Lerp between the pristine outer texture and the damaged inner core color.
  • Normal / Bump: Mask in a localized edge bevel or stylized fracture normal map along the damage borders.
  • Roughness and Metallic: Swap physical properties to reveal underlying surface types, such as dull stone beneath a glossy painted coat.
  • World Position Offset (Optional): Push vertices inward along the mesh normals within the masked area to create physical indentation for craters and gouges.

Step 6: Implement Dynamic Runtime Interaction

To trigger dynamic destruction during gameplay:

  • Spawn invisible "damage proxy" meshes with active distance fields at projectile impact locations.
  • Scale or animate these proxies over time to simulate spreading cracks or expanding explosion craters.
  • Remove or pool the proxy meshes when no longer needed to optimize performance.