I'm in Cycles Render, I've added some hair to a mesh, and then I combed it.
As you can see on the image below the hair breaks in half when rendered.
Does anyone know what might be causing this?
To see if we are on the same page, here is my broken hair:
If that is what you are seeing -- and it looks similar -- here are ideas/options:
Have you tried using the B-spline checkbox under the Particle System's Render area? Also choose a higher "Steps" settings -- although doing so increases render time... But see if that addresses the issue.
In the same vein, see if using Curve Segments as primitives (this is under the Particle Systems "Cycles Rendering" area) helps. Turn on cull back-faces and turn curve subdivisions to 4 or 5 or 6.
The image above is without B Splines and with primitives set to Line segments. My hairs break at the first crinkle... perhaps that is what you are seeing?
Above: Same as first image, but with B Splines on and Steps set to 5.