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Richard Hebert
05-26-2012, 06:25 PM
These clusters appear to be rotating. Has anybody run across this before and how did you handle it?

Richard

SplineGod
05-26-2012, 11:22 PM
how are you placing them and how are you driving each cluster?

Richard Hebert
05-27-2012, 11:46 AM
I created guide splines with a weight map in Modeler. In layout I added clothFX to the splines using the weight map to anchor the splines. Added FBX to the splines. The FBX window is included here with the geometry settings used. I then just swept the collision object over the splines to get the swaying movement. If the splines are causing the rotation because they're not just bending but rotating then how can that be fixed? I'm really new to FBX because my little Mac Mini couldn't handle them :P

Richard

Greenlaw
05-27-2012, 12:14 PM
Since you're using ClothFX, set Fix to your root points--this should lock the base of the guides firmly. Depending on how you created the guides, the root points should have a named surface you can select under the Fix list (typically called 'Root' by but it could be anything.)

Greenlaw
05-27-2012, 12:22 PM
BTW, if you're using the weight to give the effect a falloff from root to tip, I suggest using it in Viscosity instead of other channels--calculations will be faster and tweaking may be more predictable. Sometimes I'll additionally use an inverted weight in Resistance.

Hope this helps.

G.

Richard Hebert
05-27-2012, 07:03 PM
I've used your suggestion and almost all of the guides appear to be locked down with the exception of a couple. I went through the map to make sure that those guides had weight values assigned to the roots. Is it necessary to go beyond 100% values on the weight map or will that even make a difference?

Greenlaw
05-28-2012, 01:06 AM
That's very strange.

This won't help but I remember seeing something like when I was using Sasquatch on a Crash Bandicoot commercial. There was a furry creature called a Yuktopus and it used two layers of Sasquatch on its body, a base layer and some long guides, and in the first attempt of the effect I had trouble with twisting guide chains. If I remember correctly, it had to do with the fact that the character's MDD did not start in T-Pose at the beginning of the scene, which caused the character's left arm to have disproportionate influence on the guides. While I don't believe that error directly relates to what's happening in your shot, it does look similar.

FWIW, it does make me think the problem is in you dynamics setup, not FiberFX. If the base of the guides are correctly fixed, then the guides are somehow being overstressed by whatever is deforming them. It might help if show the ClothFX and Collision settings, or better yet post the scene files.

Since you've only shown FiberFX settings, I'll make a second guess: try increasing Smoothing to 2 or 3 and see what happens.

Hope this helps.

G.

Greenlaw
05-28-2012, 01:11 AM
The Fiber Width seems very extreme, which makes me wonder about the scale of your scene. Just a thought.

Richard Hebert
05-28-2012, 08:33 AM
The extreme width is to produce grass (in this case underwater seaweed for a marine shot). When creating guide splines in Modeler about how many points should these poly chains have when using it for FBX?

Greenlaw
05-28-2012, 11:29 AM
So the plants are actual size? Just want to be sure. Scale has a big impact on how FFX renders but what I'm really getting at has more to do with the dynamics system which can also be affected by unusual scale. Without knowing anything about your settings I still suspect the dynamics setup rather than FiberFX. But that's just a guess.

Anyway, the number of guide chain segments needs to be just high enough to create the wave motion you want. For example, if the grass is tall and thin, you will want more segments and if it's short and wide you can get away with fewer.

The segments affect the general shape of the grass especially in motion, but the actual 'curviness' of the fibers is determined by the Fiber Smooth property. If this value is too low, the fibers will look 'segmented'. You might think of Fiber Smooth as a 'relaxing' property for the fibers, which I think you will want for underwater motions.

BTW, if you were using surface based fibers instead of guides, you'd want to adjust the Edges property to increase the segments of the 'virtual' guides but you may still need to increase the Fiber Smooth property to make them render smoothly.

Good luck. Hope you figure this out.

G.

Richard Hebert
05-28-2012, 01:12 PM
Thanks Greenlaw, very useful tips. I'm adjusting the dynamics settings on some modified splines. I'll post the scene file if I'm still encountering difficulties so you can probe a little if you like but I really appreciate the additional insight to FBX.

Richard

Richard Hebert
05-28-2012, 01:32 PM
Out of curiosity, is there a way to save shading info. for loading into FBX? I'd like to create some settings as presets.

Richard

Richard Hebert
05-28-2012, 01:33 PM
Never mind... it's been a long day...

Greenlaw
05-28-2012, 02:33 PM
Good, you found it. :)

Tip: When you save a FiberFX settings file, you're actually saving the settings for the currently selected FFX layer, and not settings for all layers--so if you use multiple layers of FFX, be sure to save settings for each. When I'm working in FFX I make it a point to save many iterations of settings files for each layer. Here at work this habit really paid off because more than once I've been asked to drop back to an earlier version of my hairstyle settings.

BTW, just to minimize confusion, most users abbreviate FiberFX as 'FFX'. 'FBX' is the Filmbox output format.

G.

Richard Hebert
05-28-2012, 04:04 PM
GTK...That means 'Good to Know'!