Possible to turn off collision for specific body parts?
Ptrope
Posts: 682
in The Commons
Is there any way to exclude body parts from collsion, so that clothing doesn't warp out and cover them, i.e. a hand resting on a thigh or pressed against a torso, where you want the clothing to collide against ONLY the thigh or torso, not engulf the hand or the arm?
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No, it is a feature that has been much requested but it isn't (yet, at least) avaialble or hinted at in the change log.
Are you referring to Smoothing or dForce?
For dForce you could hide the handbones during simulation.
For Smoothing I am not aware of any real methods (besides turning it off, but then it won't work for the other body parts).
One workaround is to export just the legs and torso of the character as an obj. Reimport the obj, which should match the pose and shape of the figure exactly, then hide it. Change the collision of the clothing item to collide with the hidden obj rather than the character, and this will give you the effect desired.
Another way to do this is to animate the collision and make sure the hand comes in later so there is not initial collision.
Copy the figure, delete some of its geometry, and sim against this proxy instead?
Some good tips here but I agree with the OP - it should be included by now. DS5 maybe??
We can hope for it in DS5, but it really isn't going to be easy to programme.
I can remember in 2006 the forums talking about this new, future thing for draping clothes to get excited about, was it DS 1.x maybe? I said at the time (with my stress engineer hat on) that they were going to have to create a non-linear finite element analysis package to get it right, and that's not easy. It's very, very not easy. I had investigated doing it myself for my home programmed 3d FEA modeller and.. lets just say I didn't go ahead with it. When I returned in 2019 to DS 4.10 I discovered it was that very version I returned to that had got dForce, the implementation of the cloth draping talked about 13 years earlier. It's HARD to implement such things, and smothing is another of the really difficult things too.
Soft body physics with harder areas or things like internal bones giving stiffness at depth but soft to begin with. Phwee. That's a massive step in complexity beyond the cloth engine. Doing it with a 2d surface model is a brilliant way of making the complexity much, much worse as you'll need stiffness weight maps for in surface directions and the normal direction that all vary with deflection too. It's so much simpler to consider solid models for soft body physics as the solid elements can then be assigned stiffnesses and poisson's ratio behaviours that can interact sensibly using well established code, all of which are impossible or close to impossible with surface models. In the solid model, the bones would be stiff, muscle softer, fatty areas softer yet and a compromise made for the lungs & abdomen. The solid models could be fairly coarse to get reasonable shaping of the character under interactions, but the solid model would probably have to tie up with the surface model facets, which might mean it ends up more detailed than really needed - so taking longer than desired for analysis.
Please remember I'm blue sky speculating on this, I have not one idea of what DAZ are thinking, however I AM using my stress engineer experience to inform my speculation and show how difficult it could be.
Regards,
Richard.
Honestly, while they're no means perfect, I'm staggered at how well DS manages to make things like smoothing, morph auto-following and (as something of an extension) auto-fit work.
While I had to do some work to make it possible in the first place, the fact I can carry out as complicated a shape transfer as this at all is really quite astonishing:
Oh dear, that's utterly, hilariously, ridiculous.
Regards,
Richard
I have never claimed to be a particularly normal person.
But if anyone's not familiar, I can promise that transferring shapes between different meshes is not a trivial algorithm in the slightest - I've certainly seen some old Blender plugins and the like that make a real hash job of it. DS, on the other hand, does a generally good job - perhaps not perfect, and perhaps not always, but it is nonetheless very capable.
Now I've made shape clones to transfer G8 clothes to the horse body (which my ego won't let me entirely trivialise - I did have to put some work in there), I can use DS's shape transfer tools to fairly reliably convert most clothes in not all that long.
All I can think of is that Blender, Marvelous Designer and Game Engines have had things that we in the DAZ community have been asking for since the time I started with this hobby almost 20 years ago. A small independent developer like VWD included the ability to drag cloth while simulating and that was released before dForce - which still can't do that.
I'm not a software person so I'm not clear why DAZ needs to reinvent everything. There are independent developers adding desireable features to Blender for free. Why not tap into some of those skills and outsource some tasks? Instead they supply bridges which is not encouraging for the future of this software.
LOL! I am in love with that female soccer player! (hehehehehehe)
I have to second that auto fit and smoothing generally do a really good job, given the enormous number of figures and character morphs that abound in the DAZ world.
But in addition to the original request to turn off collision on body parts (even just a check to ignore hands or foot parts would be awesome), I add another request ... and that would be to specify more than one item as a collision base.
Take for example you have a long shirt or tunic top that you are going to put over pants from a completely different set. So there is no existing morph for the tunic top to fit over those pants. In that case, if you choose to collide against the pants, the upper part of the tunic might have pokethrough with the character. If you choose to collide against the Genesis figure, you get pokethrough in the areas over the pants. Ideally, it would be nice to choose BOTH the character and the pants. (Unless there is a way to do that and I am missing something somewhere?)