Physics Mod Guide: Block Breaking, Crumbling, Dynamic Blocks, Item Physics, Collapse, and Despawn Animations
Physics Mod changes how blocks break, how dropped items move, how structures fall, and how things vanish, and every one of those behaviours is controlled from the mod's own settings screens and hotkeys. This guide covers the block, item, collapse, and despawn sides of the mod.
Opening the settings
The main entry point is Physics Settings.... Everything below lives inside it, grouped into sections such as block settings, dynamic block settings, collapse settings, animation settings, and general settings. Each section has its own reset prompt, so you can restore defaults for one area without touching the rest.
Some settings only take effect after a world reload. If a change appears to do nothing, reload the world before assuming it failed.
Block breaking and crumbling
The block settings section controls how blocks come apart when destroyed. You choose between small particles, the whole block, or fractured pieces — the mod describes this as adjusting the way blocks crumble, with the exact look left to your preference.
Two settings shape where and how much of this happens:
- Activation Distance — the distance from you, measured in blocks, beyond which block physics stop activating.
- Physics Objects Scale — the size of the physics objects produced.
Related particle toggles exist for the moments around breaking: MC Break Particles, Crack Particle Physics (particles while a block is being cracked), Sprint Particle Physics (particles while sprinting on a block), Eat Particle Physics, and Block Particle Physics (particles from fall damage and other block particles sent by the server). Lifetime (Particles) controls how long those particles last.
A separate toggle, Item Break Physics, turns a broken item into a small physics object, but only in first person view and only with resource packs up to 32x32.
Dropped item physics
Dropped Item Physics governs whether items on the ground are simulated. Dropped Item Rotation Speed sets how quickly they spin.
Collapse
Collapse settings make placed or destroyed blocks trigger a structure collapse. The mod warns plainly that this can destroy your entire house. The available controls are:
- Drop collapsed items — whether collapsed blocks drop as items.
- Collapse Speed (Ticks) — how fast the collapse proceeds.
- Collapse Limit (Blocks) — the maximum number of blocks involved.
Collapse settings can only be changed in the server config, except in singleplayer.
Dynamic blocks
Dynamic Block Physics turns vines, doors, trapdoors, and hanging signs into physics objects. This section is marked as requiring the Pro version. Its controls include Load Distance (Blocks), Max. Loaded Blocks, and a note that only the nearest X amount of block physics activate. There is also a Dynamic Block Customization screen and an Edit Dynamic Block screen for per-block adjustments.
Despawn animations
Despawn Animation Settings let you build your own despawn animations for blocks and mobs — the mod's own example is mobs blowing up into smoke. You can create a new animation or edit an existing one; some particles cannot be displayed inside the menu itself, so the preview there is limited.
General limits and performance
The general settings include Physics Max Objects, which caps how many physics objects can be active at once, and Physics CPU Threads, which caps thread usage. Changing the thread count requires a world reload. Simulation speed is also adjustable here: slower values produce slow motion but also delay how quickly you can interact with physics objects, while high values are heavy on the CPU. Toggle All Physics switches the whole system on or off.
Compatibility notes
Dynamic Block physics, snow physics, and ocean physics are each incompatible with Immersive Portals and Farsight. If you use those, expect the corresponding physics features to misbehave or be unavailable.
A note on keys
Actions such as toggling physics are bound to the corresponding hotkey, which you set in the controls menu. The mod's screens are opened through its own interface rather than through crafting, and no default key is assumed here — assign one that suits you.