Pushing the limits of d-force, "draping" a cylinder
stitlown
Posts: 282
Hi all, I understand d-force is designed to help drape flat surfaces like cloth, but I was wondering if anyone has found how to trick in into working with a with-volume mesh such as a cylinder such that it drapes but keeps the fundamental cylindrical shape, rather than squashing the cylinder flat, which is all I've managed to achieve so far. Thanks in advance for any ideas. Lx
Comments
I don't think I'm following...are you trying to dForce the cylinder itself...or drape cloth on the cylinder?
Drape a cylinder, melissastjames. eg seeing if I can used d-force to help naturally drape ropes over spars and across spaces, without the 'fatness" of the rope being squashed flat.
As I see it, then basically dForce is really bad of keeping volume.
You can increase the stiffness parameters and it will partly keep shape, but it will still deform.
If it is something simple like a wire, you can do it if you are not to focused on that it somewhats deforms.
Objects with a low number of edges along the loop is better at kepping its shape. For a wire I created a long 4 sided wire that had internal edges across and that can keep its shape good enough. I then added a subdivision to it to give it roundness and that looked quite fine. But at it best you can call it a weird work-around.
It must be possible, because Sickleyield has a product that does it: https://www.daz3d.com/sy-dforce-ropes-vines-and-tubes
Don't ask me how she does it though.
All good ideas. I have SY's product so I'll play around with that.
Felis' suggestion is the best outcome so far. A 6-sided cylinder with the collision offset set to just under the space between the perimeter vertices gives an outcome that could be worked with. Another partial trick was putting eg a sphere inside the cylinder at the drape points - but that has only very limited use.
Has anyone else noticed that d-force has some truly epic fails when you tinker the paramters even a little. In my experiments I've come up with some amazing outcomes that are more like putting a stick of dynamite inside my cylinder, or beside it and blasting it half way across the universe! Awseome, but not helpful.
... Played around with one of SY's ropes, still has much of my problem.
I will agree, dForce is a finicky little princess. I've used at least five dynamic systems now (Blender, Marvelous Designer, 3ds Max, DS Dynamics Optitex/original, dForce, and VirtualWorldDynamics with the DS plugin) and they all are, with the easiest to use being Marvelous Designer (a program which does almost nothing else BUT make and drape clothing meshes, so it's kind of a specialty program that way, like Zbrush for hirez sculpting).
That said, what I did with the vines/ropes is definitely something you can do, which is that I used the Dynamic Surface Add-On feature! What you do is, you make a set of "ribs" or "supports" for the inside of your cylinder. They must be made from your cylinder mesh, so that the vertices perfectly match up the vertices of your cylinder mesh. You can look at the ones I used vs. the shapes they're made to stiffen with the wireframe on to get an idea what worked for me. Then, if your cylinder is rigged, you rig them from it to match its bends. You add a dForce modifier from the Simulation panel options, but you add the Dynamic Surface Add-On instead of Dynamic Surface. Then you make their settings slightly stiffer (again, you can check the settings I use; too stiff still tends to explode).
This allows the dynamic add-on mesh to act as a support for the cylinder. Sadly I couldn't get this to work making chains, they just overcollide between the links and fall apart, but it works fine for pure cylinders in most situations. I haven't tried it with Riversoft Art and esha's dForce magnet, but just bear in mind if you do that one of the things dForce is very sensitive about is collision from multiple directions (i.e. being held inside a hand). It can be done, but you're probably going to have to have the fingers a little looser than you would normally plan to do, then close them when sim is done.
Wow! Thanks, SY, for the detailed response. I will play in due course.
I've decided what I really want is a tool that "drapes bones" ie "drapes" the mesh by manipulating the available bone movements while still keeping the mesh pretty much connected to the bones per the orginal rigging - sort of a dynamic, iterative, posing tool that, like dForce recognises gravity and "wind" and collisions. Meantime in some circumstances, I'm using dForce on one copy of a rig to drape it and then using that as a template to pose the original rig more naturalistically.
If I had skill and time, I'd maybe try a write a script to do just that - sadly, I don't have the skill.
Cheers. Lx
Well, if you could pull that off I'd buy it. :D I don't think skeletons work quite that way in DS, sadly.