hair generate workflow

[LeoYfver]

We are gonna have a project with alot of characters with hairdos and want to do the grooming in houdini. We are thinking of saving the hairgenerate to disc as bgeo and read in to the render at rendertime. Our worry here is the disc space and the render memory. Is there gonna be a hair generate procedural or what do you guys think is the best approach.

Regards Alexis

[bdancer]

The only thing available is VRayFur SOP.
There are no plans to create any other render-time hair generator.

> disc as bgeo and read in to the render at rendertime.

Those will be still baked into a vrscene file at export time. There are no plans to support direct referencing of .bgeo files.
If you still want to bake hair into the files - bake to Alembic and use Alembic SOP to load. Then it'll export data as GeomMeshFile and will reference .abc files.

[psanitra]

They way i see it, file size probably is not going to the main issue, first you need to make a choice based on your licencing/rendering policy.

- Option A -You can have smaller files, curves in ABC, or BGEO and generate hair from simple curves on per frame basis, basically using hair generate, like you normaly do in Houdini and then submit the job to render. But that will require each render node to be able to have Houdini licence of your need(core, FX etc), open the hip file each frame it`s rendering and cook the node inside. If you have 20 render nodes, that will require 20 FX licences to run. If you have so many licences, then i`m jealous

- Option B - have the complete setup exported to vrscene sequence and render. This only require and vray render licence. No houdini licences needed.

[ronald_a]

what about caching out the generated hair to abc (instead of baking it into vrscene) and then render like in option 2. This way, your vrscene files don't take forever to create (you still need to make those massive hair abc files though).

But still, this is a bit of an unsolved issue, because there is no "hair-procedural" like I think there is for xgen in maya (or for mantra in houdini when using the hairtools). I believe for vray to be able to do the same thing that mantra does (generating hair on rendertime) it would need to be able to understand the hair tools - which means understanding pretty much every houdini node and run vex - which I doubt will ever happen. It would be nice though, if the VrayFur SOP could have an input for guide curves to interpolate.

[Gosho.Genchev]

like I think there is for xgen in maya

I was looking exactly at this a while ago, hoping we can hack it somehow to use it for Houdini's hair. Turns out all hairs are generated and exported to V-Ray in the background.

It would be nice though, if the VrayFur SOP could have an input for guide curves to interpolate.

Yup, I was thinking the same. I need to check if we can somehow do this.