nHair rest curves workflow???

#1

Hi,

I am totally not getting how the nHair Rest Curves are supposed to work. If I edit the Rest Curves, the hair does not assume the shape of the curves at all. Increasing Stiffness and Stiffness Scale doesn’t help. Disabling Solver Gravity doesn’t help.

The Maya documentation is not helpful as it does not adequately describe the workflow. I am forced to attempt to “read between the lines” to determine how this features is intended to be used.

I have disabled solver gravity due to a cryptic mention in the docs… “If the hair is fairly stiff and you want it to assume a non-straight shape (in the absence of external forces like gravity), then you can create and edit Rest Position curves.”

I have attempted to use the Stiffness attribute, which, if I understand it correctly, is actually “rest curve attract.” Note that the Stiffness attribute is mysteriously missing from the Attribute Editor, and is only accessible via the Channel Box.

With no nucleus gravity and a non-zero Stiffness, I do not get the desired result. The hair does not conform to the Rest Curves at all. I have increased the Stiffness many orders of magnitude to no effect.

Please provide some guidance. I have no idea if this is a bug, or if the Rest Curves feature is a legacy technique left over from classic hair, or indeed if Rest Curves were ever of any use whatsoever.

Thanks,

Aaron

#2

OK, I think I have figured out what the issue is.

“Stiffness” itself is currently a totally dead attribute. It does not function at all.

The “Stiffness Scale” graph, contrary to what the documentation says, is not a multiplier for Stiffness. Maybe it was in the past, but it is no longer. In fact, the Stiffness Scale graph is the rest curve attract attribute, period.

To make matters much, much worse, the Stiffness Scale graph tops out at a value of 1.0, but I need to increase that value to at least 10.0. This means that the graph area cannot display the values I need. This makes the Stiffness Scale graph less than useful.

I think the wise thing to do for the next software revision is to reinstate the Stiffness attribute so that overall stiffness range can be adjusted into the order of magnitude needed for the simulation. Then Stiffness Scale can be a multiplier ranging from zero to one.

Thank you

Aaron

#3

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.