Hi gang, Andy Moorer here. I'll try to put together a sample scene based on the Nike commercials to give some insight into using lkFabric. It's a complex enough system that getting a feel for it takes some struggling at first.
Some general quick thoughts from using it on those two commercials...
- "Stoppers" were an early addition where we were planning on using them to cut out non-square shapes like clothing patterns. We ended up not using them, because we liked the U/V shapers better. Animating the U/V shapes was much of where we did iterations of looks for the client.
- Our general workflow was to draw a series of curves on the surface of the shoe where we wanted cloth to grow, and then to loft and shrink wrap the resulting surface to our base polygonal model of the shoe and sweatshirt.
- A "thread" is a collection of strands typically spiraling around each other. A "pattern" is how threads deform to go over and under each other, or in a knit how threads interlock with their neighbor. LkFabric defines a "per strand" and a "per thread" context, and has frames of reference to shift positions in relation to strands, threads and patterns.
- Deformation was handled by transferring the resulting animated strands from a static shoe mesh to the deforming one as a post ICE process. I can't share the compounds, but it basically involves getting the closest location to each strand point on the base mesh and then reinterpreting the strand points' location on new geometry.
- Multiple pattern curves do work but it takes some care to get used to how to get the results you visualize. Because almost all of the cloth we dealt with had a very fine "herring bone" pattern once we got a set of pattern curves and settings dialed in we locked it down. As a result lkFabric hasn't had as much testing and development in making it easier to generate many different kinds of patterns, we were pushing poor Leonard for animation control. He lost a lot of sleep making this.
Your feedback in this area will likely help him improve the experience (assuming he continues to refine the system, which I think likely if he gets a lot of feedback and encouragement) but in my tests I was able to create several common knits and weaves. Keep at it! If memory serves the number of pattern curves was set to 2, which is per U and V... So 2 curves for U, 2 for V. For a knit a single looped curve is used, the pattern only would extend along U (or V,) and every other thread would be offset. Offsetting the pattern of every "n'th" thread is very useful and key to getting many patterns.
- I think the sample scene you have has threads in a helix. In the commercials we actually had several layers of these threads. In one shot we had over 80 thread curves, in fact, but this was an extreme case. 12-24 gives you a nice density, and using some randomization per strand results in a look like yarn.
- The fabric shoe in the first commercial had many millions of individual fibers. A shot which would have gone in like a microscope never happened, but we were able to zoom in on a square centimeter of the shoe and see each fiber in each thread growing. (It helped that Royale provided us with crazy powerful 'best-in-class' workstations. I got quite spoiled.)
- You can also get a nice braided look by reversing half of the spirals or getting more complex.
- There are some color tools which have untapped potential. Shooting color down threads or strands or picking up colors from an underlying mesh could create some cool effects. This system doesn't just have to be fabric, it's a pretty broad toolset for doing all kinds of interesting things with strands, we didn't have time to really explore the many possibilities.
- The options to randomize and turbulize per thread and per strand are key to a natural look. This is the area where we had the most fun, using combinations and animating these nodes to make fibers grow in various ways. Nike tends to be very conservative, we were able to get some very wild and energetic motions which we always had to dial back, so there is a lot in this area which hasn't really had a chance to be shown off yet. Look at polynoids Lenovo/"carbon" spot for inspiration, lkFabric can make very aggressive, almost explosive evolutions like that very nicely.
I know that's hardly much help, I'll try to get a scene or two put together. In the meantime keep exploring, Billy and I definitely experienced a learning curve before we had a handle on the system but there is a lot of power there too. Our priority was to push Leonard for power over ease of use because the timeframe was so tight, but as a result this system is capable of far, far more than we ever got to show. Cheers - AM