Objects - Rigid Body

Owned by thomas (Unlicensed)
Last updated: 27 Jul, 2015
2 min read

This set of parameters is only visible when the object's → “Simulation” option is set to “Active rigid body” or “Passive rigid body”.



 

Collision geometry

There are four different shapes:

  • “Sphere” creates a spherical collision hull around the object. This mode is very fast.
  • “Box” creates a bounding collision box around the object. This mode is very fast.
  • “Convex Hull” approximates the given shape with a bounding grid.
  • “Mesh” exactly represents the entire object.
Collision side

This entry is only available with “Collision geometry” set to “Mesh”. The object's normal directions define inside and outside:

  • With “Inside”, other rigid and soft bodies can only react with the object's inside.
  • With “Outside”, other rigid and soft bodies can only react with the object's outside.
@ mass

RealFlow automatically calculates an object's mass in kilograms, but you can enter any other positive value. A body's acceleration does not depend on its mass: in a vacuum, all objects will have exactly the same fall velocity regardless of the adjusted “@ mass” value. If you want to create differences please consider changing “@ air Friction”.

@ air Friction

This is the amount of resistance caused by a surrounding atmosphere. High settings can stop an object completely.

@ CG

“CG” stands for "centre of gravity" and is measured in metres. It is especially useful for floating objects, because by shifting the centre of gravity downwards, you can prevent a body from tipping. Please also read → “Quick Start Tutorials - Floating Objects”. Click on “+” for sliders.

@ Velocity

Here, the initial velocity of an → “Active rigid body” is defined. You can use any positive or negative value for the parameter's X, Y, and Z components. “@ Velocity” is measured in metres per second. Click on “+” for sliders.

@ Rotation W

Here, the initial angular velocity of an → “Active rigid body” is defined. You can use any positive (clockwise rotation) or negative (counterclockwise rotation) value for the parameter's X, Y, and Z components. “@ Velocity” is measured in degrees per second. Higher values make the object spin faster around its centre of gravity (see “@ CG”). Click on “+” for sliders.

@ object friction

Object friction occurs when bodies with uneven surfaces interact. “@ object friction” slows down the interacting objects and can even stop them completely. The maximum value is 1.0. RealFlow takes the average friction of all interacting rigid/soft bodies into account.

@ elasticity

This parameter makes an object bounce. The maximum value is 1.0.