PDA

View Full Version : Fiber FX Question



Greenlaw
05-27-2009, 02:27 PM
Hi,

Does anybody know how to make Fiber Filter fibers 'unseen by camera' or not appear in the alpha channel, but still cast a shadow? I have a character with FFX applied and I'm trying to catch a shadow from it.

Thanks in advance for any helpful info.

Greenlaw

Greenlaw
05-27-2009, 02:30 PM
Nevermind, I just figured it out. :)

In case anybody else needs to do this:

Enable 'Save RGBA' in the Etc. panel. This renders the image without fiberFX fibers visible, but it still renders the shadow cast by fibers.

Greenlaw

Greenlaw
05-27-2009, 03:01 PM
Hmm, it doesn't seem to work reliably though. Randomly, I'm still seeing the fibers, full or partial, in the renders and not just the shadows. Sometimes I'm getting different results just from pressing f9 and not changing anything. (i.e, first render, no fibers; next render, partial fibers; next render, no fibers again, and so on.)

Another bit of weirdness: when I enable 'Save RGBA', it doesn't save the expected image through the Fiber Filter panel, instead I'm getting the expected results from the standard LW saver...when this is working that is.

Anybody have a suggestion? I'll post more info here as I work through this.

Greenlaw

P.S., I'm using 64-bit LightWave 9.6 on WinXP Pro. I'll try this with the 32-bit version next.

Greenlaw
05-27-2009, 06:16 PM
Still getting random render errors when trying to create a shadow pass from Fiber Filter, x64 or x32 LightWave. Here's another possible clue, though I'm not sure to what exactly: When I render locally, I get no fibers/partial fibers randomly, but when I render to our render farm, I get fibers in all frames. (What I want is no fibers at all, just the cast shadows.)

Can't spend too much more time on this so I'm going to assume Fiber Filter is just bugged for doing shadow passes. I'll report this to fogbugz as soon as I get a chance to set up a test scene for Newtek.

In the meantime, does anybody have any other ideas for generating a useable shadow pass from FFX?

Greenlaw

Mr Rid
05-27-2009, 11:54 PM
My answer to all FFX questions would be, "Sasquatch." ;D


P.S.
I like the way you've managed to carry this thread almost by yourself.

mav3rick
05-28-2009, 02:10 AM
My answer to all FFX questions would be, "Sasquatch." ;D


P.S.
I like the way you've managed to carry this thread almost by yourself.

ahhahahaahha :)

sandman300
05-28-2009, 07:38 AM
How about baking the shadows onto the ground or whatever.

joelaff
05-28-2009, 08:32 AM
I know it sounds crazy... but you could perhaps render two passes... one with shadows turned on for your shadow catching object, and one with shadows turned off for your shadow catching object (all other setting identical). Then you may be able to pull a difference matte to get the shadows.

Slow, but might work. I have used similar techniques for other issues.

This won't get you the shadows behind the edges of the object, and probably would leave the fiber knocked out of the shadow as well if it is in front of it. But a good compositor could dilate the mask and probably make it work.

Greenlaw
05-28-2009, 03:12 PM
Hey, Mr. Rid,

Long time no see. I'll write you privately to catch up on things.

As for Sasquatch, yeah, I know. I've been breathing and living with Sasquatch for the past year and a half, making fur and hair for everything from shaggy monsters (Crash Bandicoot: Mind over Mutant (http://www.gametrailers.com/user-movie/crash-bandicoot-mind-over/273782) and Banjo Kazooie: Nuts and Bolts (http://www.gametrailers.com/video/e3-2008-banjo-kazooie-nuts/36782?type=flv)) and long styled hair for bimbos (I'm not allowed to say what that project's about yet, and I'm not sure I ever want to.) I usually get great results from Sas but it requires so many workarounds to get it work properly for compositing. Also, we only have two licenses here, which limits the number of artists who can work with it at the same time.

I was hoping that Fiber Filter was ready as an alternative to Sas as there are several compelling reasons to use it: it comes with LightWave, it's easy to set up, renders fast, works well with the new cameras and AA settings, and it looks great in single pass renders. But as you know, we never render anything in a single pass here.

The big issue I'm having with Fiber Filter now is the abilility to render a separate shadow pass. With Sasquatch, the setup isn't exactly straight forward and the results can be a bit noisy (because of the shadow mapping,) but generally I can get a useable shadow pass from it.

Fiber Filter seems to have significantly less noise in the shadows. When it's working in the tests I'm doing now, I'm actually getting a very nice clean shadow pass that seems to be completely free of noise. But because I'm getting this result so randomly, we're not going to be able to depend on this for production.

I haven't started testing for rendering separate hair shadow pass that goes directly on the character beneath the hair; I should test this next just to see if Fiber Filter can even do this. In Sasquatch, creating this pass can be a pain because the result almost always requires a bit of tweaky post-processing and garbage masking to work properly in a comp. I can deal with that for a few shots in a game trailer or a TV commercial, but it is nearly impractical when you have to do this for hundreds of shots for a game cinematic. I'm hoping that I'll be able to get a more readily useable 'skin shadow' pass using Fiber Filter, but this random render bug is a real show stopper.

Sigh! Fiber Filter really is so close. :bangwall:

To everybody else who responded: thanks for the tips. I think I'm going to have to wait until this issue is fixed though; I'm trying to avoid replacing one set of workarounds for another, and I'm really just looking for a straightforward solution to this problem.

I think I'll have time to whip up a test scene that I can send to NewTek and fogbugz it today. The shadow pass capability is clearly there already, so hopefully they will look into fixing this random render problem soon. :)

Greenlaw

mav3rick
05-28-2009, 04:44 PM
yea FFX is so close to really replace sasq... i am satisfy with render quality and styling... i miss internal dynamic .... that's what i miss else i can live with

Greenlaw
05-28-2009, 05:48 PM
Okay, here's an illustration of what I'm dealing with. I can't post my actual test renders for NDA reasons, but I found that I could reproduce this problem exactly using the terrific wolf scene that came with the LightWave 9.6 Bonus Content files.

Here's the breakdown:

Panel A. This is the original render of frame 0 from the scene, locally rendered.

Panel B. This is the RGB channel of my shadow pass, also locally rendered. But of course what I'm really interested in is...

Panel C. This is the shadow matte I want, from the alpha channel. Looking good, but...

Panel D. When I press f9 again, I get this. Same frame, same settings, different render.

Panel E. Pressing f9 again gave me this...more unwanted fur creeping back into the render. The degree of visible fur varies each time I press f9; occasionally, it returns to rendering correctly, as in panel C.

Panel F. Network rendering through BNR produces an even more puzzling result: now the fur is completely visible in the scene, in every frame.

Now, I know I can garbage mask what I see in panels D and E, but this is really stupid to have to do every time I render the scene and get different results each time. Also, garbage masking will only work in this particular situation; it won't work if the shadow pass I want is on the skin of the creature beneath the fur.

Oh well, at least now I have a demonstrable bug that I can send in to NewTek. (Go get 'em guys!) ;)

Greenlaw

Mr Rid
05-29-2009, 12:02 PM
My, arent you optimistic FFX is going to get fixed. Its another feature that is only as production reliable as its weakest link. Have found a few missing links in the FFX chain that have rendered it unuseable for anything weve needed it for so far. Although I was able to make leaves for a tree using Strand Modeler. But the only thing I can think of is to bake the shadow using the surface baking camera. I use it for a little different purpose, to pre-bake shadows into Sas fur so you can save a lot of render time and should be able to do the same with FFX.

The baking camera will save out a sequence of UV maps for a selected mesh (must have a UV) with lighting and shadows baked. This sequence is then applied in the color channel of the fur to drive the fur colors along with shadows, so fur self shadow tracing never has to take place. Or you could render out a black and white sequence of shadow info only on a white, diffuse object and then apply the resulting UV sequence to the diffuse channel of the fur, and handle the color separately. There are a few other little kinks to the process like not using subdivided objects or MDD baked objects, and you have to trick Sas into seeing a texture image as a sequence by applying the UV sequence as an unseen texture somewhere on the mesh. Who knows what gotchas FFX may have with this approach. Am just fed up with NT advertising a feature that is not really finished or production reliable.

adamredwoods
05-29-2009, 12:56 PM
Keep sending bugs to NewTek. They've stated there will (eventually? when?) be a LW 9.6.1 release.