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View Full Version : too bad we are not all bald! (a rant on LightWave Hair)



michaeldejong
09-15-2010, 01:11 AM
So, I'll make this one real quick and hopefully someone can help. Its late and im tired. Anyway, ive been trying to get some scenes going with FiberFX. However since its a post-process, I cant reflect the hair on any surface. So if I want a character in the mirror he is not going to have any hair is he ? Secondly, the hair itself cant receive any GI information which kind of disappointed me.

anyway, not trying to be negative as I do love LightWave and plan to stick with this software. please though - any help or suggestions ?

Dodgy
09-15-2010, 06:40 AM
Did you turn on Reflections in the FFX panel?

It does reflect...
Likewise in the FFX panel, there's a radiosity toggle. Turn that on for hair to be affected by radiosity.

michaeldejong
09-15-2010, 10:37 AM
Thank you Dodgy, for taking the time to reply.

I had turned on reflections but still the scene seems to be reflecting mostly the base mesh of what ive applied the fiberFX to and not the entire result.

Also, dont know how I missed that Radiosity check-box lol.

should wait till morning and a cup of coffee before I post questions I guess ;)

I will keep going forward. thanks again.

Greenlaw
09-15-2010, 10:48 AM
This is a workaround but when we render a character with Sasquatch hair and fur that needs to be reflected in a mirror, we place a camera on the other side of the mirror in the opposite position of the character, and render a fake 'reflection' sequence. You can then composite the result in post, or if you must have it integrated in the scene, map the 'reflection' image sequence to the mirror's surface and then render the scene as normal.

P.S., You'll need to flip the image sequence of course.

P.P.S., Now that I've had some coffee, here's a correction. The 'mirror' camera needs to be opposite the scene camera, not the character's POV. (Unless, of course, the scene camera is the character POV.) Also, if there's camera motion, you'll need to mirror that too. (Which can be done with a motion plug-in, expressions or Relativity, or manual editing in the graph editor.)

michaeldejong
09-15-2010, 12:12 PM
that sure seems like a complicated detour. I know not all workflows in LightWave work the way they 'should' in a real world setting. ie I was hoping to just have my character walk past a mirror in the hall and have everything reflected. It does reflect some of the fiber strands but leaves most of the surface as bare. Or if I wanted a little mouse that scurries past an old Vase with a blurry reflection, this would seem to be another thing I could not do.

Greenlaw
09-15-2010, 12:55 PM
It's really not that complicated. In fact breaking out fx elements simplifies getting exactly the result you want for your final output and can eliminate potential problems.

In general, we consider hair and hair reflections an fx element, which are always broken out into layers to save time. It's much more efficient to tweak elements like this in post than in cg. For example, if I needed softer cast shadows from a character's hair, I would just blur the shadow layer in post...no need to mess around with shadow settings and too many test renders.

This is just my opinion of course. :)

michaeldejong
09-15-2010, 03:33 PM
well ill be honest, I am a little disappointed that my virtual scenes can not be rendered the way I thought would be logical. What about looking through a glass on a table with a cat standing behind it. how would I achieve this ?

I do know about different passes but have only seen it when doing research or using trials of other software, I was not aware this can be done with LightWave.

Where can I learn more about this 'post' process that you spoke of. The only software I own is LightWave (I am just a hobbyist at this point in my life). Seems like the more I learn the more I realize - I know very little.

Any help/comments or links are greatly appreciated.

Sorry for all the newbie questions.

thanks in advance.

Greenlaw
09-15-2010, 04:26 PM
No problem, that's what these forums are supposed to be for. :)

Just to be clear, you *should* be able to render FiberFX in the mirror and through glass. The problem is the feature isn't working quite right, so the suggestion I'm offering is the workaround we use for Sasquatch renders, a system where we don't even have the option to render hair and fur in reflections.

Anyway, if you're going to render everything in one pass, your best option for the 'mirror hair reflection' might best be to render a mirror image sequence from behind the mirror as described, and then texture map it to your mirror object. The downside is that if you change your animation, you'll need to re-render the mirror image sequence, so you should be sure your animation is done and ready.

The advantage of course is that you won't be wasting a lot of time trying to trying to make a broken feature work.

In the meantime, you should file a fogbugz report, and when the next update comes out, test the feature again and see if it works.

Regarding 'post', I'm talking about compositing rendered cg layers and elements in another package. In my case the program is Fusion. After Effects, Nuke, and Shake are other popular composting programs. You can technically composite within LightWave by mapping your rendered image sequences to polygonal cards and rendering through them; this is how many of us had to do it 'back in the day.' :)

However, there are more controls and options available to you in a dedicated composting program, and you might spend less time trying to nuance things in 3D, which can be very time consuming.

Hope this helps.

dwburman
09-21-2010, 11:07 AM
You might be able to render it all at once by setting up the second camera as Greenlaw suggested, but instead of rendering out a separate sequence you could apply the CCTV shader to the mirror and have it show the output from the 2nd camera.

I haven't tried doing this so I can't say it'll definitely work.