Inventory Physics

Inventory Physics is a client-side mod for Minecraft 1.21.1 (NeoForge) that replaces the standard static 3x9 storage slot grid in the player's inventory with a 2D physics chamber. Items inside behave as physical rigid bodies that fall, collide, bounce, and interact dynamically.

Key Features

• 2D Rigid-Body Simulation: Main inventory storage slots (9–35) are simulated inside a physical chamber using SAT (Separating Axis Theorem) collision detection and sub-stepping.
• Material-Specific Properties: Different item types have distinct physical parameters (mass, friction, bounciness, air damping, and collision box dimensions):
  • Heavy blocks (anvils, stone, netherite) have higher mass and lower bounce.
  • Slimeballs bounce higher.
  • Feathers float down slowly due to higher air damping.
  • Ice has significantly reduced friction.
• Player Movement Inertia: Jumping, falling, and vertical movement impart dynamic inertia to the items inside your inventory.
• Interactive Drag & Toss:
  • Drag items with the left mouse button.
  • Throw items across the inventory chamber with cursor momentum and spin.
  • Drag items outside the inventory window to drop them into the game world.
  • Right-click to split stacks.
• Collision Auto-Stacking: When identical stackable items collide or are thrown into each other, they automatically merge into a single stack.
• Tactile Hover Feedback: Hovering over an item scales it up slightly (~1.22x), adds subtle magnetic pull towards the cursor, and renders a soft highlight.
• 2D GUI Particles:
  • Throw trails behind fast-moving items.
  • Impact sparks on item/wall collisions.
  • Floor dust when heavy items land.
  • Starburst effects on stack merges.
• Sound Effects: Collision sounds scale their pitch and volume dynamically based on item mass and impact velocity.
• In-Game Configuration: Full in-game config screen (via the NeoForge Mods menu) allowing you to adjust or toggle:
  • Gravity, bounciness, and friction sliders.
  • Hover impact effects, scale, and magnetic force.
  • Auto-stacking on collision.
  • 2D particle effects and collision sounds.

Technical Details & Compatibility

• Client-Side Only: Does not need to be installed on servers. Fully compatible with vanilla and modded multiplayer servers.
• Logical State: Logically, items remain in standard vanilla inventory slots. Crafting grid (0–4), armor slots (5–8), hotbar (36–44), and offhand (45) retain standard slot mechanics.
• Requires: NeoForge 21.1+ (Minecraft 1.21.1).

mod config

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