Structural integrity

Structural elements form a connectivity graph rooted at grounded elements. Three update rules are common. Connectivity only: an element with no path to ground falls, as in Dwarf Fortress cave-ins and in Teardown, where disconnected voxel pieces become physics bodies. Decaying support: support propagates outward and drops by a material-specific amount per connection, and pieces past the limit collapse; Valheim shows this with a color scale from blue (grounded) to red (at the limit) while the hammer is equipped, and stone and core wood carry farther than wood. Load and stress: a physics solve computes member forces and breaks members past their strength, as in Poly Bridge. Collapse removes elements, spawns debris or rigid bodies, and re-checks dependents, which can cascade.

Building with gravity in mind. Players add pillars, braces, and stronger materials, read the support overlay, and feel tension when extending a span. Collapses are spectacular, and demolition becomes a tactic.

• propagation model: connectivity only, per-step decay, or physical stress
• per-material strength, maximum span, and support loss per connection
• what counts as ground or an anchor
• collapse resolution: instant removal, debris, or simulated rigid bodies
• visualization of support before failure

• Connectivity-only models let large structures stand on a few voxels; reviewers noted Teardown does not model compressive stress.
• Per-step decay limits feel arbitrary when they do not match the visual mass of the structure.
• Cascading collapse destroys hours of player work with no warning or undo.
• Large collapses cause frame-time spikes.

• Attackers and players target supports, turning integrity into a combat and demolition system.
• Material limits shape architectural styles, such as regular pillars and stone bases in Valheim halls.
• Fire, explosions, and digging couple into chained collapses.

• Can learned surrogates of finite-element stress make physically plausible load paths affordable in large player-built structures?
• What collapse warnings preserve tension without making failure trivial to avoid?