Objects - Rigid Body

Owned by thomas (Unlicensed)
Last updated: 25 Aug, 2016
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 → “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.