TIP : 7.5c - Skin Thickness Quick tips

[kevman3d]

I did a demo of all 3 or so new features in 7.5c last night at our LWUG - I whipped this little 'tip sheet' image together based on some of the things I discussed relating to Skin thickness

Plus I am like real bored so I figured I'd play about in Photoshop to fill in some time! I just realised its also got a few typos in it... Doh! :)

Cheers!

Kev

[phaedrus]

great post,
I havent had time to experiment with all the new stuff yet & you've just inspired me to play!
thanks for posting this for everyone to share. one of the many reasons lightwave is so cool.
I appreciate all the other cool stuff you've done too, & I guess that doesnt get said enough, (though we're all quick to jump down peoples throats when they screw up...)
thanks Kevman..

[mangray]

Thanks for the great Help :cool:

nice day
mangray

[kevman3d]

Thanks guys - I'll try and quickly whip up tips for the other 2 tools (SurfMixer and Spline Control). :D

Interestingly, Surface mixer is also probably an underrated enhancement that I don't think is appreciated by a lot of people as far as some comments I've heard since people discovered it...

SurfMixer actually blends across ALL attributes of a surface - Including bumps, luminosity, colour, and whatever else you have going on in there - Imagine trying to add some kind of cross-dissolve effect in a layer? What if the previous layers in a texture contained complex gradients, alphas and procedural effects all working together? Now you wanna cross fade that to anothet complex mixture of layers? How? Lucky we now have SurfMixer! :)

One of the best examples of how this can be used was suggested by one of the guys at last nights LWUG - The example of the Lizard character in Monsters Inc, how his surfaces acted in a chameleon type manner! Take one lizard and just blend him into his background at will! :)

Also, Surface mixer can mix based on textures as alpha, so you're not only limited to cross-fading effects. I created a mixture of 3 surfaces at the LWUG - I blended a crusty rock texture from one dummy polygon onto a polka-dotted sphere. I then added ANOTHER surfmixer onto that polka-dotted sphere and used a fractal to blend a boiling lava texture I'd animated on a dummy object on top of the crusty rock, which was on top of the polka dots!

Nice crusty lava flow on a corroding polka-dotted spheroid! I couldn't even imagine creating the complex set of layers on just one texture to create something this cool!

Anyway, that said (and hopefully inspiring you to just go and have a play yourselves!), here's another experiment I did with Skin Thickness... Its my old robot - I just made him into a green perspex looking object with one Gradient on transparency!

Its not perfect - It needs work to look fantastic, but for less then 2 minutes fiddling... Cool! :)

[colkai]

Kev,
Any chance you could post links to some presets we could tear apart to see how you set these things up.
I got a reasonable effect last night by setting gradients on transparency, colour and luminosity, but it never seems to have that truly "thick" look you and others seem to get. The object was double sided, does it need to have a proper "air" surface to get the full effect?

I just know I'm missing one vital bit here ;)

[kevman3d]

The preset would be primitive to say the least! (Can't do now, but I'll try grab it later once I power this machine down and plug the LW beasty back in)

All I did was this:

* Double side the polys
* Attach gradient to transparency with 'Skin Thickness' active

Just make sure you get that Gradient set right for the skin thickness - Basically you wanna use like a 0% at 0m for Transparency, then just set the next key real close for starters - Test render and then adjust a bit more until you get the look you're after...

You may find that the thickness value is smaller then you thought. Make it tiny and work up from there. :)

Of course, the problem with the robot is that its got all kinds of thin pieces that don't always work with the generic surface texture I slapped on it, so I'll need to break some of those surfaces into 'parts' and adjust the gradient accordingly to get a better look

The shoulderblades are a good example of the current thickness setting not working - See how they look 'cut-out' cause they're too thin! :D

[kevman3d]

Ah, I did have some raw nasty examples on CD from the LWUG - I've zipped them up and I'll try and attach them to this post for you to rip to shreds...

Note these are like 5 minute quicky examples - No prizes for quality rendering, but I hope they'll be useful! :)

Note: In the depth-Attenuation example, remove that bump map from the water poly - You can see the effect a little better without it I discovered later on! :)

[colkai]

Thanks for that Kev.

Well you didn't do anything I didn't according to your message (have to wait till tonight to scope out the presets). However, I'm guessing the gem is ..
You may find that the thickness value is smaller then you thought.

My first key in the gradient was at about "halfway" - so for sure that will be my first 'target' for attack.

Thanks again, really appreciate it! :cool:

[kevman3d]

No worries! In fact, its what I did at first (just slap a key right in the middle). Its here where you realise you never modelled to scale! Doh! :) I think those wierd glassy things (wierd_plastics) are too big for example - I can't test on this PC, but I recall they are like a meter or so in the gradient to look right?

BTW, I realised I've been fumbling between calling this Skin Thickness and Surface Thickness...

It should be Surface Thickness. I guess for most people, they don't really care, but its something that's been bugging me when I read my own posting back! :)

[kevman3d]

Heres an example of Depth using Surface Thickness (its the same one thats in that Zip file). Just for those who wanted to see, rather then read! :D

[toby]

I think we have another Mac-PC discrepency here - I've been trying with no luck to get good at using the surface thickness gradient, so I loaded your scene, turned off the bump, turned the diffuse down from 100 to 33 and hit f9. (with diff at 100 it looked luminous). Notice the falloff is not as gradual, and the edges of the pool turn white, even with diff at 0.

I have a mac, and assuming you're on a pc.

[toby]

oops

[toby]

I tweaked it and zowie - and I learned something new! reflection was the culprit, it was behaving in an 'additive' fashion, don't know if that's realistic or not - I removed it and it fixed it, but water needs a little relection, so I applied one incidence angle for reflection and an opposite one for transparency.

I also had to triple the thickness value from 500mm to 1.5m, strange that the settings had to be so different

Props to :cool: Kevman for the kickstart!

[ninjaman]

Toby!

I tweaked it and zowie - and I learned something new! reflection was the culprit, it was behaving in an 'additive' fashion, don't know if that's realistic or not - I removed it and it fixed it, but water needs a little relection, so I applied one incidence angle for reflection and an opposite one for transparency.

I also had to triple the thickness value from 500mm to 1.5m, strange that the settings had to be so different

Could you please post your latest scene/object files? I haven´t been able to replicate your latest tweaks.

Regards

Johan Grönwall

[toby]

Sure!
I think all you need is the water object, let me know if this works -

[ninjaman]

Works like a charm! Thanks!

Johan

[kevman3d]

Hey folks!

Something else that's cool you might like to try with the Surface thickness options is applying this gradient control to the Refraction Index. Note that it for a gradient on this value, the values range in percentages rather then the usual IOR values - However gradients are pretty easy to use - Just remember they work like this:

100% = 1.0
150% = 1.5
etc.

We tried this on a caustics tutorial I was running at the last LWUG - You can create some pretty cool effects with a little experimentation! :)

[toby]

hey, I was wondering about the % thing!

muchos gracios

[kevman3d]

Originally posted by toby
hey, I was wondering about the % thing!

No worries! Yeh, it had me confused at first - One of the guys at the LWUG pointed out 'maybe its like 100% = 1.0, same as LW works in some plugins and LScript'

Sure enough - Viola! :)

[Flashfire|REAL]

Except in the case where you will be playing with RGB values, in which case 1.0 = 255, where 0.5, 1.0, 0.75 would translate to 128, 255, 192.

Just a note... you can avoid the whole reflection issue by not using the thickness gradient at all, and instead use a depth map (generated at render time by the buffer export plugin).

[toby]

depth map instead of thickness gradient - sounds complicated, do you mean compositing it or putting into one of the surface channels?

how would you constrain the effect to the area between the bottom of the pond and the surface of the water, without keying, that is

[kevman3d]

I would probably just use the depth to control the % of the reflection so that thinner water was less reflective...

Hmm, a depth buffer... Interesting idea - Its essentially a buffer of pixel distance to the camera. You could use it I guess for something, maybe if you front-projected the map back and used it as an alpha or input for a gradient? How about application in animation - That would entail a lot of extra buffer rendering to a sequence.

Flash, I'm Curious - sounds like a lot of extra work, but I'd be keen on any pointers or tips on this idea... :D

[SplineGod]

Great info, Thanks Kev!
Heres a quickie test I tried on one of my head models.
I was surprised how easy it was to set up and it renders quickly.
http://www.3dtrainingonline.com/personal/ogre_head_glass.jpg

[caesar]

Quite impressive

[toby]

Great image SG -

This thread certainly deserves to be ressurected every now-and-then, I'd still be clueless about thurface sickness without it

[policarpo]

here's my weak *** attempt.

thanks for the info guys.

:D

[policarpo]

damn...fPrime roxx!

Thanks Steve Worley!!!

http://www.policarpo.us/cgi-bin/images/graphics/blog/021296-big.jpg

[SplineGod]

Pretty cool. Im partial to the first one. It looks more like injection molded plastic. :)

[tburbage]

Wish I had read this thread when 7.5c first came out. After a few crashes, I stopped experimenting with Surface Thickness (probably didn't have ray traced transparency turned on on those first F9s......)

Thanks for the tip.

My renderings seem to have an awful lot of noise in them -- at medium enhanced AA -- with or without shading noise reduction on. Still working on that one...

[kevman3d]

lol! Trust me, the whole raytrace transparency thing seemed to confuse a lot of people... You weren't the only one! :)

Its a cool option... Wonder whether 8 will bring anything new or update this in any way? We'll just have to wait and see I guess!

KEV

[mr_nebel]

Are you sure surf mixer blends the bump maps? In the tests i just did it didn't seem to, unless i'm missing something important.

[kevman3d]

lol! Don't you just love old posts that come back to haunt you! :)

Read the DATE on the original post first and you'll notice that this is now pretty *old*. ;)

No you are correct, bump maps don't work properly, that plugin definitely is sadly a tad buggy (though it will work in VIPER, just not when you actually render - Maybe its been fixed in 8?)

In fact, there's another thread in this forum on this exact topic about Surface Mixer from about the same time as this posting started. You can read it here:
http://vbulletin.newtek.com/showthread.php?s=&threadid=4965&highlight=surface+mixer


However, luckily there is a free plugin that DOES work and does the same sort of thing...

http://home.att.ne.jp/omega/tabo/3dlabo/p_lwp.html

The plugin TB_2ndSurf is pretty cool. It is a little different in that its got its own 'implementation' of the surface editor...

Also you wanna check out the rest of his plugins while your there - They ALL rock! :D

[toby]

holy cr@p! there's a 'bevel edge' SHADER on that plug-in page! How well does it work? I don't have a pc.

This could be bigger than Normal Mapping!

[kevman3d]

As always, Mac suffers from lack of cool free plugins - I use a PC at home, but I teach LW at a school with a Mac classroom - So its always a bit annoying to have to say to students 'Yes, you can do that - There's this fantastic plugin, however we can't run it here cause we are using Macintosh systems'

Its probably mostly due to most developers just can't afford a Mac as well as a PC, and most Mac owners probably aren't developers... I know I could never create Mac plugins when I was developing them years ago - Lucky for me, Ken Woodruff did a lot of volunteer Mac recompiling for me and many others...

Anyway,

Yep, that edgebevel shader is great! Saves having to remodel anything if you wanted microbevels, or even modelling microbevels if it becomes a modelling 'complexity'...

All his plugins are fantastic! iplane is another - Creates an infinite plane using volumetrics - With a texture editor, and the iplane can be at any height, and CAST SHADOWS as well! Great for those infinite oceans, or fractal skys (check out his example render)

BTW, if you go to his homepage and check out his other software, he's also got a nifty node-based texture generator (stand alone) called 'deep shade' that appears to so some kind of subsurface thing... and some other tools he's written... One cool developer IMHO!

[SplineGod]

Its two things Kev,
Macs do cost a lot more then PCs and the reality is that theres not enough ppl with macs that buy plugins.
When the ortho tools were first sold publically before Newtek aquired them , Irrational number had LOTS of requests for a mac version. The problem is that the requests are never backed up with wallets. In the end the cost of time, money, equipment and so on has to be offset with people actually buying things. The amount of Mac users hitting the page was so low that it didnt justify for doing it for no return.

[toby]

not a big deal. about the same as when any of us sees a cool plug-in that turns out to be for 3dsmax. We do lose out on the 'coolness' factor, but all the ones you actually need for production have been ported -

'cept maybe this Bevel Shader - it's such a great idea, along the lines of Smoothing and Bump mapping; saves time/work and geometry - if it becomes as popular as it should, (has anyone else thought of it?) it'll get ported soon enough. I'm going to see what Richard Brak and Mr. Woodruff think about it

[peteb]

Just seen this link form another thread. I'm still confused by surface thickness. I can understand it working if it measured the distance between one poly and another. So for example the lake stuff people are doing. The polys making up the surface water are the first polys and then the lake floor is the second poly. So the lakes floor in the middle of the lake will be further then the lakes floor near the shore line. So the transparency will be a lot less in the middle then the edge of the lake. This seems logical and I can see how Lightwave can look at these distances and work out the thickness. But if you just had a set of polys that were double sided they don't actually have any real distance as they're paper thin so how does it work out thickness?

pete B

[toby]

Did you read the the paragraph in the first image kevman posted?

"thickness is measured from one polygon to the next, but if the normal is facing the wrong way..."
That's why they need to be double sided - if there's only 1 layer of polygons it won't work, whether they're double sided or not.

[peteb]

Yeah I did read it I guess I'm just a bit stupid. So what you're saying is you need polys behind you can't just have a flat grid and make it have thickness?

[Dodgy]

One thing to note is the Intel version doesn't crash now when using gradients without trace transparency on. It doesn't work, but LW doesn't crash either :)

Can anyone confirm this for mac?

[SplineGod]

peteb,
That is correct. The best way Ive found to understand how it works is set up some simple tests with a flat grid with a warped grid in front. Use simple objects and see how it works. :)

[toby]

One thing to note is the Intel version doesn't crash now when using gradients without trace transparency on. It doesn't work, but LW doesn't crash either :)

Can anyone confirm this for mac?

Doesn't crash on the Mac either -

[Dodgy]

Woo hoo :)