Attaching Springs

There are two ways to create springs and attach them to rigid bodies. Either the springs can be created using the Rigid Springs dialog or the springs can be drawn in the viewport using the RBS Draw Tool

Using the Rigid Springs dialog, you can create, edit and attach springs as well as adjust all of the properties of the springs including elastic and plastic behavior.

You can select and edit multiple springs. To add a spring to the selection, Ctrl click the spring’s name or number in the spring list. To remove a spring from the selection, Ctrl click once more.

If the settings of the selected springs differ — e.g. if one spring has a Rest Length of 50 and another a Rest Length of 30 — the parameter boxes that hold the differing values will be highlighted with a bright color. You will still be able to enter new values using these highlighted parameters. The highlighting is simply to make you aware that the corresponding values currently differ for the selected springs.

When you change a setting, the new setting will be applied to all of the selected springs, regardless of whether the parameter was highlighted or not. If you need to specify an individual parameter for a spring, you must select that spring only and edit it separately.

Add

The Add button creates a spring. The spring will appear in the spring list, which is the large region in the left half of the dialog.

Having created a spring using Add, you need to define which rigid bodies the spring should be attached to. To do this, enter the names of the rigid bodies under A and B. You must type in the names exactly as they appear in the Object manager. To the right of A and B input boxes are two further input boxes. Use these to define two points of the rigid bodies to which the spring should be attached. The default value of -1 will attach the spring to the mass centre. To change this, enter the point’s number.

Name

You can optionally type in a name for the spring.

Angular

Enable this option if you want to define the spring as an angular spring. In this case you should enter the name of the rigid body under A.

Add

Creates an empty spring that has to be linked manually

Delete

Deletes the spring that is currently selected in the spring list.

Duplicate

Duplicates the spring that is currently selected in the spring list.

Calc. Rest

Sets the Rest Length value to the spring’s current length. This is useful after you have attached the spring to two rigid bodies since it will set the Rest Length accordingly.

Show Springs

Use this option to turn the display of springs on or off in the viewport.

Working with already defined springs

If multiple list items are selected whose spring settings differ from on another, << Multiple Values >> will be displayed in the corresponding setting’s value field. Once a value is entered into this field it will apply to all selected springs.