Hair styling experiments

[amm]

Hello,

I made this just to get a bit familiar with Houdini. Basically, it is a re construction of particular hair setup from small Softimage ICE hair system, which I running for some time. Let's say the principle is to get the main shape of hair first, using as much generalized method. Details comes later. All that without any traditional brushing over curves. So, this one uses the emitter and two NURBS surfaces, as complete 'manual' part of work. In first stage, there's xyz distance node to get UV closest to hair root, in next  stage, this info is used for getting the positions along one or two NURBS surfaces, and distributing the curves between them.

 

Of course it's also a personal test of Mantra procedural fur, hair shading model as well. Screenshot of setup is there is just for basic info - most likely I'll change it, as this new, Houdini environment, already gives the new ideas.

Hope this is just a start of 'half-procedural' hair styling experiments in this app.

 

 

 

 

[michael]

very nice!

looking forward to more

[jim c]

Wow that's really cool. I've been fiddling around with something like that, but never quite got it to work this well or controlled. Are you using the Fur shelf tool, or just using the Fur SOP and customizing it all manually? How did you go about getting the hair curves to follow the cage shape?

[amm]

Thank you guys.

 

Wow that's really cool. I've been fiddling around with something like that, but never quite got it to work this well or controlled. Are you using the Fur shelf tool, or just using the Fur SOP and customizing it all manually? How did you go about getting the hair curves to follow the cage shape?

 

It's not a fur shelf tool, I think this is visible from screenshot. Following the screenshot, 'vopsop set uv' has a xyz distance node, which takes the closest UV from nurbs cage. Later on, 'vopsop shaper' uses the u value ( if 'u' is parallel to hairs) for starting point of interpolation along nurbs, using 'primitive attribute' node. End point is just an end of u along nurbs. Hair guides are interpolated between two nurbs surfaces, or just pushed along normal of one, according the same u value, retrieved from 'xyz distance'. Later on, there's interpolation between hair root and some point on nurbs surface, and another interpolation between - to get the smooth transition from hair roots to interpolated UV along nubs surface. Basically, it acts like Houdini 'creep' surface operator, but with a lot of re-positiong before, blending at start (roots) as well.

It's not secret recipe, it's part of Softimage ICE open source hair system, which I'm running from 2009. However, as I'm really new in Houdini world - got the Indie few weeks ago - I'd really like to be more familiar with software, before telling anything more detailed about this, Houdini implementation.

Edited September 25, 2014 by amm

[amm]

Hello

this one goes a little bit further. As it is noticeable, there is a 'hair cut' by  external geometry, or 'hair boolean'. This time I've added hiplc file, having a complete setup - should render the same thing as in pic. Graph with curves and dots, is for brave people who like to dive into hair styling setup, colors are corresponding to colors of sticky notes in 'vopsop_ follow_nurbs', in 'kristinka_cut_by_volume' object. For those who already played with Kristinka Hair for Softimage ICE, I need to say, this is far away from complete thing. 'Original' has a number of protections against user's error, small additions in every ICE compound, so on. That is, chances to 'step into hole' are a few times higher, with this, experimental setup in Houdini.

Get hiplc here

Edited October 12, 2014 by amm

[pelos]

thanks for sharing the file. great example on how to use vops.

[amm]

Thank you, pelos.