[Sidefx-houdini-list] furry holidays

jeff at sidefx.com jeff at sidefx.com
Wed Jan 2 10:42:41 EST 2008


And a bit more info.

The default Fur Procedural (added in the Material as a Mantra Fur
Procedural SHOP) will use a cvex shader in the manner described below: It
passes in each point of each procedurally generated curve so you can work
on it.

As for writing the actual cvex shader, I either use VOPs (for quick and
dirty) or write one with vex code and compile in the SOP context. I use
the SOP context and test on actual curve geometry in SOPs. The exact same
thing is happening at render time. Even more technical, writing a Mantra
procedural (with c++) uses the same code constructs as that for SOPs. When
dealing with Mantra procedurals, I treat it as SOPs.

With that now understood, you can create your SOP VOP network, test and
approve on the resultant curves from a Fur SOP. The Mantra Fur Procedural
generates the identical curves just millions of them if you want. ;)

Next write the SOP vop code to disk. In the line that says "surface",
change that to "cvex". Now compile on the command line with

    vcc my_fur_cvex.vfl

This will compile a cvex shader. If you are on Windows, please use Wordpad
to edit the .vfl file generated from the SOP VOP network. Textpad adds
1970's DOS return characters. I prefer vim and you should seriously look
in to cream as your next text editor (built on vim).

Now all that is left to do is to reference this cvex shader in the Mantra
Fur Procedural SHOP in your fur Material.


-jeff

> ok I will
> thanks
> z
>
> On Dec 30, 2007 12:47 AM, Andrew D Lyons <tstexture at gmail.com> wrote:
>
>> Try the H9 alpha forum...
>>
>> Cheers
>>
>> On 29/12/2007, zoran arizanovic <zoran.arizanovic at gmail.com> wrote:
>> > thanks francois!
>> > I havent found much either on odforce or in docs
>> > z
>> >
>> > On Dec 29, 2007 3:20 PM, François Duchesneau <sidefx at trinix.ca> wrote:
>> >
>> > > I've haven't played with cvex really but here's what I know about
>> it,
>> > > hoping I'm not saying things wrong.
>> > >
>> > > You write your shader to give some frizz or whatever effect to your
>> fur.
>> > > Otherwise each fur simply interpolate from each guide fur on the
>> > > primitive vertices. There's a unique number attribute per
>> instantiated
>> > > fur to help you create random function. You can also create and
>> paint
>> > > your own custom attribute and use them in the fur shader to control
>> the
>> > > intensitiy of whatever look you give to your fur.
>> > >
>> > > So basically the global shape of the fur is controlled from the
>> guide
>> > > curves and all the rest is in the shader. I wonder if there are not
>> new
>> > > tools of higher level in H9.1?
>> > >
>> > > Hope this help anyway!
>> > >
>> > > François
>> > >
>> > > zoran arizanovic wrote:
>> > > > Hi
>> > > > i have some time finnaly to look more into fur in h9
>> > > > I am having troubles with it
>> > > > could someone explain me about these cvex shaders
>> > > > how do i create them and for what should I use them
>> > > > thanks
>> > > > and all the best to all on the list in 2008!
>> > > >
>> > > _______________________________________________
>> > > Sidefx-houdini-list mailing list
>> > > Sidefx-houdini-list at sidefx.com
>> > > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>> > >
>> >
>> >
>> >
>> > --
>> > Zoran Arizanovic
>> > http://arizanovic.blogspot.com/
>> > _______________________________________________
>> > Sidefx-houdini-list mailing list
>> > Sidefx-houdini-list at sidefx.com
>> > https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>> >
>>
>>
>> --
>> ======================================> Andrew D Lyons | Digital Artist
>> | http://www.tstex.com
>> ======================================>
>> _______________________________________________
>> Sidefx-houdini-list mailing list
>> Sidefx-houdini-list at sidefx.com
>> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>>
>
>
>
> --
> Zoran Arizanovic
> http://arizanovic.blogspot.com/
> _______________________________________________
> Sidefx-houdini-list mailing list
> Sidefx-houdini-list at sidefx.com
> https://lists.sidefx.com:443/mailman/listinfo/sidefx-houdini-list
>





More information about the Sidefx-houdini-list mailing list