Manual Modules Dynamics Rigid Bodies Rigid Body Spring Tag
Using the RBS Draw Tool
Although you can create and attach springs using the Rigid Springs dialog, the RBS Draw Tool is preferred in most cases because it enables you to draw the springs interactively in the viewport.
Springs that you create using the RBS Draw Tool will still appear in the Rigid Springs dialog. Hence you will be able to edit the spring parameters such as elastic and plastic behavior later using the dialog.
Before you create the springs, first ensure that you have assigned a Rigid Body Spring tag to the Solver object (File > Dynamics Tags > Rigid Body Spring Tag in the Object manager menu). Ensure also that the rigid bodies are children of this Solver object. Next, select the RBS Draw Tool (Plugins > Dynamics > RBS Draw Tool in the main menu).
To draw the spring, drag from the first rigid body to the second rigid body. As you drag, a cross will appear where you first started dragging and a second cross will appear once the mouse pointer is in a suitable position over the second rigid body. When you release the mouse button, the spring will be created and placed between the two crosses.
Using the RBS Draw Tool, you can create and attach springs interactively in the viewport. Two crosses will appear while you draw to indicate the attachment points.
Attribute Manager Settings
Auto Correct Equal Names
This option is enabled by default. If you draw a spring between two rigid bodies with the option enabled, the names of the rigid bodies will be changed automatically to ensure they are unique within the scope of the solver. For example, assuming there are three rigid bodies in the solver all named Cube, when you draw a spring between two of the bodies, they will be renamed Cube.1 and Cube.2. This automatic renaming is advisable so that, when you later use the Rigid Springs dialog, it will be clear to which objects each spring is attached.
Multiple Spring Check
When enabled, this option will prevent you from creating a spring where a spring already exists between the two points.
Add RDB Tag Automatically, Rigid Body Mass
If this option is enabled when you draw a spring, Rigid Body Dynamic tags will be assigned to the two objects that the spring is being attached to. The mass defined under Rigid Body Mass will be assigned to the tags. The tags will not be created if the objects already have Rigid Body Dynamic tags assigned.
Snap to Points
Enable this option if you want the cursor to snap to object points while you are drawing the spring. If the option is disabled, the spring will snap to the mass centre of the objects instead.
Calculate Rest Length
If Calculate Rest Length is enabled while you are drawing a spring, the Rest Length of the spring will be set to the distance between its two attachment points. In other words, the spring will be at rest between the two points, hence the spring will exert no force.