Simulate

Use Blender physics to simulate a cable with collisions while maintaining the low points number.

Please note that since Blender doesn’t support physics for curves, the function could give weird results — especially in difficult scenarios with a lot of intersections and colliders. In most cases Simulate should be considered as a base for further manual adjustments. Please check the Best Practices section below for some hints.

  • Only one curve object can be simulated at one time however the curve object may contain several splines (aka sub-curves).

  • If Mesh objects are selected before running the function they will be considered as colliders for curves.

  • By default the first and the last points of each spline are locked in place. For locking specific points, select them in Edit Mode before running the function.

Simulate Options:

  • Fit to Geometry Below: with this option enabled the curve will try to better fit the geometry below. This option give best results when there’s a complex geometry to collide with;

  • Expand Length: will make the cable curve longer;

  • Curve Points Multiplier: with the default value set to 1 the result of simulation will have the same amount of points as the original curve had. However in situations when simulating with a collider it’s better to have more points. Change this option to add more points effectively increasing the resolution;

  • Debug Mode: when enabled the result of the Simulate will be a baked simulated mesh object — the simulation can be played using the Blender Play Animation button. This could be helpful to understand what’s happening in case of weird / unexpected results. Also could be useful to look for a specific frame to stop the animation. Use Undo to restore the pre-baked curve back;

  • Use Custom End Frame: by default the 400st frame of the simulation is used. In some cases it could make sense to use a different frame: if the result of Debug showed some better results;

Best Practices for Smulations

  • consider the location and number of curve points before simulation: sometimes less points give better results, sometimes adding one-two points could help the curve to achieve a better simulated pose;

  • it’s possible to lock specific points in place: select them before simulating;

  • in some cases it makes sense to cut a complex curve into smaller parts using the Cut Bezier Curve helper; use Merge End Points to make the curve single again;

  • Cut Bezier Curve helper is also useful to separate the result of a simulation of a Create a Mass from Selected Faces before editing — separated curves are easier to edit;

  • for laying the curve down on a large flat surface consider using Drop the Cable helper instead;

  • other curve objects can’t be colliders: if collsision against a curve is needed duplicate a curve, convert the duplicate to a mesh and use the duplciate as a collider. Remove it after the simulation;

An example of tweakening a curve for achieving a particular simulation result. While the first simulation gave an adequate result, I wanted to have a little a hanging part on the left. I first re-run the simulation in Debug mode and noticed that frame 70 gives a result I like. So I rerun the simulation with this custom end frame. However the result was too wobly. In the end I decided to lock a specific point in space: selecting a collider object first, then going to Edit Mode and selecting the points to lock. This finally gave a result I was satisfied with.