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LK Fabric from Leonard Koch

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gustavoeb
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Re: LK Fabric from Leonard Koch

Post by gustavoeb » 22 Oct 2013, 23:28

:-o

speechless

Bullit
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Re: LK Fabric from Leonard Koch

Post by Bullit » 23 Oct 2013, 02:44

Many thanks it appears nicely simple at first sight, at least the construction tree is.
I also deform the grid and the strands follow ok.

You say in a LKF core node note
You can decrease the "thread count" values for performance, and increase to the full number at render time.
I don't see any "thread count" input in LKF core, is this the "Number of Thread Curves" or the "Thread Repetition Length"?
There is also a drop down menu: Full mode, Simple mode, etc but i didn't saw any noticeable difference in performance between those first 2. I ended up tweaking the LKF Surface creator parameters to get speed.

What is the sideways and backwards moving pattern?

Small notes:
-A typo in "LKF slide profile over UV" ppg in that it says U parameters also in V.
-In LKF creator there is a red node that seems to not make problems says self.LKFFlowActive

It seems with way it is constructed it can't start irregularly in middle of the grid and spread in UV positive and negative directions from there unless some modification and also start at several places.

Matic
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Re: LK Fabric from Leonard Koch

Post by Matic » 23 Oct 2013, 04:38

Bullit wrote:Many thanks it appears nicely simple at first sight, at least the construction tree is.
Yes, most of our setups were pretty straightforward. We approached the complex stuff like the shoe with multiple pointclouds, each which had a simple setup like this to cover a single part of the model. I think the most detailed shot had about 17 LKFabric pointclouds, each one animating a small section of the shoe to create the overall illusion.

There is also a set of nice compounds for making single threads form down curves, it's very effective and easy to use. We used that for the "fly wires" which act kind of like a skeleton inside these shoes. The shoes are incredibly complex in RL and made up of several layers of different types of cloth. For a while I was worried we would have to do all the internal layers, which was worrying since we only had 3 weeks and only 3 of us knew ICE, plus of course Leonard who was busy coding away.
I don't see any "thread count" input in LKF core, is this the "Number of Thread Curves" or the "Thread Repetition Length"?
It would be the "number of thread curves." Sorry, some of the names have changed over time. The "thread repetition length" is how many times the shapes of the thread input curves are repeated down the length of a thread, the smaller the number the more "twisted" the look (and the more strand points used, more memory etc)
There is also a drop down menu: Full mode, Simple mode, etc but i didn't saw any noticeable difference in performance between those first 2. I ended up tweaking the LKF Surface creator parameters to get speed.
That's valid. The behavior of the "mode" drop down changed several times and I forget how it ended up, this changed since we used it. The idea is to be able to turn off the "threads" behavior and just see a single strand for each thread. Kind of a "level of detail" control. But it also was used to handle an inner "shadow core" strand which is used for a rendering trick I won't get into here and some other things, and I'm not sure just hat it does now. We should ask Leonard to do a walk thru video sometime (I know he wanted to, he's just been super-busy lately.)

You will also see a lot of repetition of values, for instance you can change the strand and thread widths in several places... This is intentional but the differences are subtle except in certain circumstances. When Leonard was making this tool for production use we asked him to expose more than you typically would for a commercial tool - we wanted power over ease of use. I think in future versions LK is likely to hide some of this stuff away. :)
What is the sideways and backwards moving pattern?
Some patterns need pattern curves which loop back on themselves. An example would be a knit pattern, which is shaped kind of like the Greek symbol "omega." But looping backwards takes a little more horsepower and we had scenes with many millions of strands so we needed a switch... This is one of those things which can probably be hidden away and left on the slower-but-more-flexible "backwards" setting.
It seems with way it is constructed it can't start irregularly in middle of the grid and spread in UV positive and negative directions from there unless some modification and also start at several places.
Yes that's true. When we had areas like that we would make two separate surfaces and ice trees, one for each direction of travel. You can also do a cheat, which we had in mind but never had to do:

There was a possibility that we might want to use an animated vertex map (a weightmap or texture map) in ICE to make a kind of organic growth, where a noise/turbulent pattern grew over time... The solution is to make the fabric but not animate it directly... Instead use the map to set the strand scale. Where the map is zero, the strand scale is zero and the strand appears invisible, as if it was cut. Where the map is 1, the strand scale is normal. This way you can have the strands grow without limitation.

We had this idea in the back of our heads but avoided it because there would be other issues to solve if we did it this way, most importantly you can't easily see the results in your viewport... With constant changes happening we didn't want to have to get stuck rendering just to see what we were doing, nor did we have the time to develop solutions just for visualization: it was easier to deal with the limitations of 4-sided surfaces but actually be able to see pretty clearly exactly what each strand was doing. :D

- am

Leo
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Re: LK Fabric from Leonard Koch

Post by Leo » 23 Oct 2013, 05:19

Hey guys I'm glad that you are experimenting with LK Fabric.

I'm sorry to hear that some of you are having difficulties getting started.
It is quite the complex tool and I really would have liked to have at least one tutorial out with the release.
Unfortunately I barely had time to properly get out the tool before leaving the country for a month, and so didn't have time to put together a comprehensive tutorial.

Thanks a lot to you Andy for jumping in, you have answered all these questions very well!
It's great that you give everyone so much insight into what went into making the tools and where some of the decisions for certain workflows come from. :)
As Andy already said, this was built in a production environment for exactly that. There wasn't a ton of time and some things are really just focused on maximum control instead of ease of use. The sheer size of the LKF Core compound is a good example of this. I really tried though to make it a generally applicable tool everyone could use.
I will definitely do a walk-through video as you suggested.
Something you wrote and that everybody should take to heart is that a lot of the power lies in the utility compounds when plugged into the Progression on the Creator. This is shown nicely in your sample scene and the one that comes with LKF.

The knowledge you've put out there in this thread should be a great resource to anyone starting out with LKF.
Thusly I've made a little blog post on the site which points to your blog and this thread.
Here: http://leonardkoch.com/blog/2013/10/23/ ... ndy-moorer

Thank you so much for helping people out!

@Bullit, thank you for the feedback and the tip about the U&V naming in particular. I'll fix it with the next version.

Bullit
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Re: LK Fabric from Leonard Koch

Post by Bullit » 23 Oct 2013, 17:09

Thanks Andy for explanations and the tip about strand scale, also Leonard for added input.

Added: it only works with Nurbs isn't it? - Nevermind of course with UV's...

Added2: since i am a :ymdevil: person i was trying to break it, so i put a 90º step and passed the trap with flying colors.

Leo
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Re: LK Fabric from Leonard Koch

Post by Leo » 26 Oct 2013, 07:46

Bullit wrote:Thanks Andy for explanations and the tip about strand scale, also Leonard for added input.

Added: it only works with Nurbs isn't it? - Nevermind of course with UV's...

Added2: since i am a :ymdevil: person i was trying to break it, so i put a 90º step and passed the trap with flying colors.
Hah! ;)
Glad to hear that you are starting to get some good results with the tool.
Let me know if you come up with anything you'd like to show off, I'd love to put it up on the site.

And yes, it is unfortunately only fir nurbs, which tend to work quite well in this sort of context.

Bullit
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Re: LK Fabric from Leonard Koch

Post by Bullit » 03 Nov 2013, 22:49

Thanks. I have been busy so just tried with a closed surface. The image only shows the U, V obviously starts in the imaginary line between first point of each curve.
With care i think it can be made just start where the U already started to not appear that it started from nothing.
Clipboard-1.jpg

vektrex
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Joined: 03 Apr 2012, 00:17

Re: LK Fabric from Leonard Koch

Post by vektrex » 14 Jan 2014, 18:49

Hi, first of all thumbs up for the plugin, it is great!
I'm building some carpets, I want to drive the strands color with a texture map of the grid emitter but the result is a randomization of the texture colors onto the strands, can u help?
Thanks.

Leo
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Re: LK Fabric from Leonard Koch

Post by Leo » 15 Jan 2014, 01:10

Glad you are liking the plugin.
What you are trying to do is trivial in theory.
You just need to get the "LKF Get Strandcolor from TextureMap" compound, connect the geometry with the texture map on it and connect that to the strand color port.
I assume you are already doing that.
The reason that it looks like each strand has a random color from the texture-map is, that softimage can't display strandcolor (an individual color for every strand segment) and instead just displays the particle's color.
The particle color, just like the color of the strand segment is set to the color of the texture map at the closest location on the geometry.
So datawise everything is in order, but it displays the particle color data for the whole strand, that's why it looks random.
Unfortunately neither softimage's viewport nor its default renderer mentalray can render strandcolor, even though almost all the built-in strand compounds support it.
The superior Arnold however does. That is what we used in production. I think I remember that vray does as well, but I'm not sure.

Tldr: MentalRay&Softimage don't support Strandcolor. You have to use Arnold to render it.

vektrex
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Re: LK Fabric from Leonard Koch

Post by vektrex » 15 Jan 2014, 01:36

Thank you Leo, I'm using arnold, I made a mistake in the color attribute of the pointcloud material.
Now it looks correct.
Again, compliments for your work, it's really useful, I'm designing some patterns on fabrics, your addon came in the perfect time! :)
Looking forward to see some news from your work. Keep going!

missingkey
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Joined: 19 Dec 2012, 19:16

Re: LK Fabric from Leonard Koch

Post by missingkey » 07 Feb 2014, 19:49

Hi Leonard, this is great stuff! many Thanks!

I'm probably the only linuxMint / Softimage user out there, but I'd be happy to have a go at compiling for mint/ubuntu systems...

Thanks again!

NNois
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Joined: 09 Jun 2009, 20:33

Re: LK Fabric from Leonard Koch

Post by NNois » 07 Feb 2014, 22:02


Leo
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Re: LK Fabric from Leonard Koch

Post by Leo » 07 Feb 2014, 23:21

Yeah, a linux compile for CentOS is now available in the downloads section of my site.
Here: http://leonardkoch.com/download/
Thanks for this goes to Ruben Vandebroek and Jeffrey Dates from The Mill.

If you want to compile LKF for another linux distro please let me know, so I can make the source available to you.

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