hey guys,

From what i gather, the fur sop generates sample hairs, and then a fur procedural and/or a CVEX shop is what gives the fur its shape, count, tip width, root width etc? Am i right about that…. probably not .

But one thing i have no idea about is a CVEX shop. Is this a shop written in Vex converted into a shop? because i cant edit/view the code nor the network.

If anything ive said is right then all the power of creating the physical attributes of the fur is in this format (like count, width, etc).

Is this something that will become the norm or is this just a placeholder untill some other development is done, because i dont know all of the attributes that i can use to tweak fur and seems very complicated for my finite brain , i would love a workflow video on how to get this working, even the examples out of the box dont render and when you figure out how to do so, they are far from any desired effect.

I know the dynamic interaction is pretty well done, in terms of being intuitive. Would love something like that to happen on the rendering side.


thanks


-andy

edit/ ive just seen SYmek's thread, so does this mean to render fur i have to code in c++?

phrenzy84
From what i gather, the fur sop generates sample hairs, and then a fur procedural and/or a CVEX shop is what gives the fur its shape, count, tip width, root width etc? Am i right about that…. probably not .

The Fur SOP generates hairs from a skin surface and interpolates the shape from a set of guide hairs. The mantra fur procedural performs the same operation as the Fur SOP but runs within mantra and reduces memory requirements by only instancing hairs as needed.

The Fur SOP/procedural can also copy attributes from the skin and guide hairs to the resulting geometry. For example, if you are using a shader that needs some custom attributes like UVs, this would copy them to the new hairs. For separate “tip width” and “root width” values, you would simply create a “width” attribute on the guide hairs that varies from root to tip and tell the Fur SOP to copy it to the output with the “Guide Attributes” parameter. “width” is a special attribute mantra uses when rendering curves.

CVEX shaders can be used to manipulate attributes (and some special properties like vertex position) before they are used by the Fur SOP/procedural. The Fur SOP's help describes all of the special properties. Several of the Fur SOP's examples illustrate how this can be used to manipulate the fur's density and style.

phrenzy84
But one thing i have no idea about is a CVEX shop. Is this a shop written in Vex converted into a shop? because i cant edit/view the code nor the network.

The examples from the Fur SOP's help were all written in VEX. You can view edit/view the code by right clicking on the SHOP, choosing “Type properties…”, and then clicking on the “Code” tab. They were compiled using a command line like “vcc -l myshader.otl myshader.vfl”

phrenzy84
If anything ive said is right then all the power of creating the physical attributes of the fur is in this format (like count, width, etc).

There is a lot of power in the flexiblity of the system: just create some attributes on the skin and/or guide hairs and update the CVEX code to use the attribute values when deciding how to manipulate the vertex positions. Unfortunately, it still requires the user to do some VEX coding.

phrenzy84
edit/ ive just seen SYmek's thread, so does this mean to render fur i have to code in c++?

Not at all. CVEX is a powerful tool for controlling the look of your hair/fur but you aren't required to use it. You can create nice looking fur by just using the traditional AttribCreate SOPs and Copy SOPs.

thank you guys for making things abit more clearer.

Im happy to know i can use the good ol' attribCreate for specific things.


but i feel in the dark a little bit with the attributes i can hook up, is there a reference yet, i know about density, scale, etc, but i cant seem to find the rest.

Is there some locaiton i missed in the help or is it yet to be released?

again thanks derrick and wolfwood.


-andy

phrenzy84
but i feel in the dark a little bit with the attributes i can hook up, is there a reference yet, i know about density, scale, etc, but i cant seem to find the rest.

Is there some locaiton i missed in the help or is it yet to be released?

The help and examples for the Fur SOP in 9.0.706 have been made clearer.

cheers derrick,

The help in houdini is always my first port of call when things dont go as planned. Glad to see an update. Cant wait now

thanks again.


-andy