physics

Physics

Sections

• Introduction
• Rigid bodies
  • Rigid body configuration
  • Basics of moving a rigid body
  • RigidBody API Explained
• Static bodies
  • Creating a static body
• Trigger bodies
  • Creating a trigger body
• Ray cast
• Physics World
• Vehicle simulations
• Soft Bodies
  • Creating a soft body
• Cloth simulation
  • Creating cloth simulation
• Common pitfalls / troubleshoot
  • Wrong scale / rotations may break simulations

Introduction

Armory is designed to work with any physics engine. Internally, a glue code is written which binds the physics simulation. This lets you pick the most suitable physics engine depending on project needs and makes Armory future-proof.

If no rigid body is detected in the scene, Armory skips including the physics module to save space and performance. To force the physics module, set Armory Project - Modules - Physics from Auto to Enabled.

By default, Armory is configured to use a full featured Bullet physics. If lighter engine is sufficient, Oimo physics is provided. With Oimo, triangle mesh shapes are approximated using convex hulls.

To pick active physics engine, set Armory Project - Modules - Physics Engine property.

Rigid bodies

A rigid body is a type of body that can be used to simulate physical interactions between solid bodies.

To start using rigid body simulations in Armory, they have to be enabled for Blender first. To do so, simply select the object that will interact in the physic simulation, then go to the Physics properties tab, on the Properties editor, and click on the Rigid Body button.

If you hit Play (default F5), the object should be immediately free falling out of view

If this doesn't occur for any reason, you may want to give the troubleshoot section a look.

After you click Rigid Body, you will notice that an array of options will appear. These options allow configuring rigid bodies and are explained in details below:

Rigid body configuration

Type

This options allows setting what role has a rigid body in the simulation. There are two roles or types of rigid bodies, Active and Passive.

• Active are mostly used for physics objects that must be controlled through physics interactions (e.g. a character or a car). They are affected by gravity by default.

• Passive rigid bodies may be used for objects that are not controlled by physics and should interact with Active rigid bodies (e.g. a platform or a wall). They are not affected by gravity by default.

Basics of moving a rigid body

RigidBody API explained

Static bodies

Creating a static body

Trigger bodies

Creating a trigger body

Raycast

Physics World

Vehicle body

Soft bodies

Creating a soft body

Cloth simulation

Creating cloth simulation

Common pitfalls / troubleshoot

Wrong scale / rotations may break simulations

Make sure your Blender objects that interact in physics simulations always have scale of (1.0, 1.0, 1.0) (rotation and location may be arbitrary) inside of Blender:

You can always apply the scale from within Blender by selecting the object, opening the Object menu entry and then navigating to Apply and then clicking on Scale, or simply hitting the shortcut Ctrl + A and then hitting the s key or simply selecting the option from the floating menu.