Curve Guide Force Field not working on converted mesh

Hi there :slight_smile:

inspired by the cg cookie tutorial ( i want to simulate traffic on a road with two lanes. lane 1 going in 1 direction, lane 2 going in the opposite direction.

but i am always stuck at a problem with the curve guides force field.

my approach until this point:

  • i take a bezier curve as my base, model the curvature and extrude it in the geometry tab to get the with of the road itself.
  • to get two matching traffic lanes i then convert the curve to a mesh, add some loop cuts where i want the individual traffic lanes to be on each side of the original road curvature.
  • then i separate both loop cuts into individual objects and convert them into curves again. this way i get perfectly aligned traffic lanes.

but here comes the problem.
i place a particle emitter at the starting point of the curve and set the curve to be a curve guide force field.
but then the whole thing always freaks out and the curve guide doesn’t seem to work at all.

does anybody know a trick to make it work?
has anybody encountered similar problems with converted meshes as curves before?


Hi Blender82,
When Curve Guide Force Field is enabled on curve, you need to have 2 circles, which represent start and end.
When curve is created from mesh, these 2 circles are missing. To solve this, you can Join your curve with another bezier curve (with bezier selected at last), and then delete the vertices you don’t need.
Also check the curve vertices radius : it represents the distance (how far) the particles can be from the curve.