Displaying Contacts

To help troubleshoot material- and contact-related issues, Vortex® Studio Editor can display the contacts on-screen in the form of colored lines.

By pressing SHIFT+C, while running the simulation, you can display the contacts. Contact normals are white, green, red or magenta (see image below). Contacts may also appear blue if the contact normal force is less than 1.0-6 N.

If you don't see any contact lines, right-click in the 3D View, click Debug Display, then check Contact.

As can be seen in the image above, contacts are separately into two groups:

  • Contact matched: In this case, contacts were present in a previous step (e.g., a box or set of vehicle wheels touching the ground) and are located in the same place as in that previous step. Note that contact matching is only performed when the Slip Displacement option is enabled.
  • Contact non-matched: In this case, a new contact is made (e.g., a box falls and hits the ground), or the Slip Displacement option is not enabled.

Within each category, you can have sliding contact (i.e., a dynamic, moving contact with kinetic friction) or a non-sliding contact (i.e., static friction).

Pressing ALT+C cycles the contact types according to the following sequence:

  1. Contact Force: Green
  2. Contact Torque: Blue
  3. Contact Penetration: Yellow
  4. Contact Direction: Cyan

Example of contact direction lines (left) and contact force lines (right)

It is possible to change the scaling of the lines, to provide better readability, with the following commands:

  • ALT+X: Halves the length of the lines in the contact display
  • ALT+Z: Doubles the length of the lines in the contact display