vray hair is not adhering to displaced surface

mental ray for Maya 2013
mental ray: version 3.10.1.4, Jan 31 2012, revision 165283
Windows 7 64bit

How can I get hair to follow a displaced surface? Example, take a plane, apply a displacement map to it and grow some vray hair grass. the hair grows from the location of the flat plane, not the displaced plane.

Is there a way to force vray to calculate displacement before calculating the hair?

-ctj

Likely you’ll have to make a dummy, invisible surface with some pre applied displacement using whatever internal tools maya has so you get a better placement.

joconnell is right; there is no other way to go for the moment. You can use Maya’s ability to turn displacement to polygons.

Best regards,
Vlado

yes that would be great to have the displacement calculated before the hair…

There would have to be a separate displacement slot in the hair object; since the displacement is computed at render time, it’s not available from the base geometry when the fur needs it.

Best regards,
Vlado

oh Vlad…next you’re going to tell me there’s no Santa Claus! I thought the great Oz could make all our troubles go away.

;^)

pre-displaced geo it is then, but that means the geo’s going to get pretty heavy.

Joconnell,

Thank you. I was exploring that route myself, but still hoping that I was just missing something.

Cheers.

You can do the displacement stuff with this plugin: http://www.hajimenakamura.com/hajime/cg/mll/displaceD/displaceD.shtml

Paul

Or you could go to Modify > Convert > Displacement to Polygons…

Best regards,
Vlado