Physics Simple

App: apps/physics_simple/

A minimal physics demo: physics bodies are created automatically from Blender’s native Rigid Body settings when a .blend is instantiated. No Wren physics creation code is needed. The floor (static) and cube (dynamic) interact via Jolt.

Run from root

% ./plume3d physics_simple

or

Run from app directory

% ./../plume3d .

What it does

• Loads Models/SimplePhysics.blend and instantiates four collections: GameCamera, GameLight, Environment (static floor), PhysicsCube (dynamic cube).
• Physics bodies are automatically created from each object’s Rigid Body settings in Blender — no Physics.addDynamicBox call needed.
• Space — toggles physics pause/resume (Physics.setSimulationPaused).
• R — resets the cube position, zeroes velocity, and wakes it up (Physics.setPosition, Physics.setLinearVelocity, Physics.activate).
• Shadow mapping is enabled: light.castsShadows = true, Graphics.setShadowMappingEnabled(true), Graphics.setShadowMapSize(2048).

game.toml

[Game]
name = "physics_simple"
version = "0.0.1"

[Window]
width = 800
height = 600
resizable = true

[Physics]
collision_layers = ["Default", "Floor", "Cubes"]
collision_matrix = [[0,0], [0,1], [0,2], [1,2], [2,2]]

Blend setup

The blend must be created in Blender with the Plume3D addon. Key objects and their settings:

Object	Class Name	Node Id	Rigid Body
Camera	GameCamera	main_camera	—
Light	GameLight	main_light	—
Ground plane	(in Environment collection)	—	Passive, Box
Falling cube	PhysicsCube	physics_cube	Active, Box

Set Collision Layer to Floor on the ground and Cubes on the cube. Set Game Config Path to game.toml so the addon shows named collision layers.

APIs

• Physics — setSimulationPaused, setPosition, setLinearVelocity, setAngularVelocity, activate.
• Resource — loadBlend (bodies auto-created on instantiate).
• Graphics — setLights, setShadowMappingEnabled, setShadowBias, setShadowMapSize.
• Light — castsShadows.
• Scene, Node, Camera.

Expanding further

• Add Physics.onContactBegin to detect when the cube lands.
• Add Physics.addImpulse to let the player kick the cube.
• Spawn more cubes with Physics.addDynamicBox in code.