View Full Version : [FFX] UV Map Checkbox, what does it do?

03-08-2018, 10:53 AM
In Fiberf FX, under the Options tab, there is a checkbox for "Use UV Map".

What does it do? How does it work?

I mean, the docs say :

If your mesh has a UV Map you can use it, rather than texturing the hairs directly. As an example, you have a UV-mapped leopard model with an image for the fur. Using UV Map here will color your fibers according to that texture.

But they give no direction where to go from there. Is there some sample content that covers this? If not, is there some who can explain it? I'd appreciate it.

In the past, I'd assign the UV map from the surfaces I was rendering FFX on to the Textured Color, and it simply worked. While the same thing appears to work now as well, I'm having problems with getting a pattern to come up in the fur (My solution was to render @ 4x, and scale the image down). So now, I'm exploring my options.

03-08-2018, 03:10 PM
I used it for the Brudders thing I did a while back. Basically, it lets the guides pick up the colors from a texture map, provided the base of the guides have the same uv coordinates as the mesh.

If you're using Edit Guides, you get that automatically because the guides come directly from the mesh points.

But if you're generating your guides from elsewhere, like ZBrush FiberMesh, you'll need to project the coordinates from the mesh to the guides. You can do this using DrainBGVmap (available from Dodgey's website,) Liberty's Weighter 2, or OD Tools Transfer Maps.

Some notes:

DrainBGVmap only works with x32 LightWave, so it's not available for 2018. Also, because it's x32 only, there's a significant limit to the number of guides you can work with. (Transferring mesh vmaps to the Brudders cats guides was about the max I could pull off with DrainBGVmap.)

I haven't been able to get Weighter 2 to work without crashing ever since updating to Windows 10. According to Kat, it should work so your mileage may vary.

OD Tools Transfer Maps does work in 2018 and with Windows 10. I haven't tried it with FiberMesh guides yet but it should work.

03-08-2018, 03:18 PM
One more thing: I seem to recall having to process the texture specifically for FiberFX, although my memory about why or how is a little fuzzy. Maybe I had to blur it or sharpen it, or somehow exaggerate it to get the guides to pick up the colors just the way I wanted.

BTW, I haven't tried this in 2018 yet. Busy working on a different personal animation project with 2018 at the moment. There's hair but no textured fur in this one.

03-09-2018, 09:55 AM
So, I would have to generate a style for this to work with procedural fibers? I have a UV Mapped mesh, but when I have the Use UV Map check box checked, they turn out black.

03-09-2018, 10:17 AM
If you mean using Edit Guides, yes. The guides are rooted to the mesh so they share the UV map of the mesh.

Otherwise, you'll need to transfer the UV map from the mesh to the roots of the guides. This is easy to do with the vmap transfer plugins mentioned above. Just use the mesh as the source and the root points of the guides as the target, and the UV coordinates will get transferred to the root points.

Currently, OD Tools is the only one that works for me in LW 2018...but I'm also still testing it for practical production use. Hopefully, there are no 'gotchas' I'm not aware of yet. :)

You can use these tool for other vmaps like Morphs and Weights too. So, for example, if you have endomorphs for a character's face, you can project the map to the guides, and they will move with the face. (I think I did this for the cats' where I had some joint morphs.)

The usefulness of transferring weights is obvious but one thing that surprised me back when I was starting to work on Brudders, is that externally created guides do not conform to sub-divided meshes. Actually, this should be obvious too because unattached guides have no 'base' to sub-divided...d'oh! Anyway, if that becomes an issue, rigging the guides using the transferred mesh weight maps certainly helps.

It's been a while since I last used UV mapped textures for externally created fiber but I think this info is still valid for LW 2018. I hope this helps.

03-10-2018, 12:59 AM

And now for some more FFX Insanity. There is an issue that has been driving me nuts; The fibers on the tail near the hind legs line up and form neat rows, despite having a bump map applied (and masked by a weight map). I have a bit of splay (25%) applied to the body fur, attempting to spread the clumps out from their base a bit as well.

The last time I ran into this, I used a weight map to control some noise via nodes to constrain it to the area, but a lack of a node editor in FFX makes things one big kludge (The node editor available from a "T" button is lacking, requiring a work around to get a weight map's value).

Any suggestions?

03-11-2018, 12:12 PM
I'm guessing the polygons are getting smaller and denser in the tail? What happens if you reduce the fiber thickness towards the region, remove Splay completely, and use only Bump to vary the angle of the fibers (use a small value though)?

03-11-2018, 05:16 PM
I'm working on correcting the uneven polygon size right now; Splay has to be cranked up in order to get a decent effect, so I'll be removing it, I'll work on getting some bump in that area. Do you recommend Root Only, or not?

03-11-2018, 06:09 PM
I guess it depend on how it's set up. I recall when using regular surface based fibers, Splay spreads the fibers from the center of each polygon, which can make that 'grid' effect more pronounced. If that's what's happening here, setting it to zero, will make the fibers go straight up from the polygon. Applying Bump can randomize the directions of each fiber slightly, making it look more natural across polygons.

Try both. Root Only angles the fibers without affecting the shape of the fiber. Applying it to the entire fiber will obviously change the look. Unless the fibers are really long, it might just be a subtle difference.

I hope this info is helpful but take it more as suggestions. I have to confess that lately I've been busy with other stuff in LightWave and not working as deeply with FiberFX like I used to in 11.x to 2015. I hope to be doing more 2018 FiberFX very soon.

BTW, that's a cool looking character. :)

03-11-2018, 11:57 PM
<Suggestions Snipped, but noted>

BTW, that's a cool looking character. :)

Thanks. However, it's my acid test for several things - FiberFX (There are 5 layers of hair and fur (The main body fur is very dense and fine), which leads to 30+ second lags as some 32 million fibers update) and Rigging (Done in RHiggit 2, but still takes quite some time to do. And it's waaay beyond my very meager animation skills.

03-13-2018, 01:35 AM
Removing Splay and adding some root only bump to that area (gotta love weight maps) did the trick. I also re-did the tail geometry, making the quads a more uniform size Gah, I hate re-doing UVs in Lightwave,,,)

03-13-2018, 07:55 AM
so there is no way to get the root points in the uv map with out these plug-ins?

03-13-2018, 10:04 AM
Assigning the UV Map to the fiber primitive via the image map node withou using the "Use UV Map" checkbox still works.

03-13-2018, 10:14 AM
That's good to know. My experience with the new fiber primitive is very limited and I'm still learning new tricks with 2018. Thanks for sharing the info! :)

03-13-2018, 01:38 PM
how do you get that to work? everytime i connect a uvmapped texture to the hair color, it crashes layout.

Also my end goal is to use octane with this.... which does not crash, but also does not map the texture correctly using the root UV's

03-14-2018, 12:58 AM
This is the way I've done this since LW 9.5, when FFX was more crash prone than a bunch of 5 year old kids in a bumper car ride...

I don't have the Use UV Map check box checked. I make sure any guides for long hair are off in their own layers. I would use textured mode, and connect an Image node with my UV Mapped texture to the textured color input.

In lW 2018 you have to use the surface editor for the primitive assigned to that layer.

And that's how I got this:

So, in many ways, the 11 year old workflow I came up with still works.

03-15-2018, 07:16 AM
everytime i connect a UV mapped texture to the hair texture input and hit render, it crashes lightwave to desktop instantly. :(

03-15-2018, 11:05 AM
One, I would report the fact that the exception is not being handled properly. At the very least, FFX should catch it and pass it to Lightwave's exception handler, instead of going straight to the desktop.

Two : Create a small scene, with a UV Mapped box, and apply FFX to it, use the texture map for the fur, and see if it still does it. If so, you now have a small scene to give to the Devs with your above report.

If it doesn't, then there is something else playing merry heck with FFX in your scene. You might have to rebuild the scene, step by step..