How can I add "substance" to an object so that it interacts with dForce clothing.

denisnormandin

Hi, I have a scene where a woman is sitting on a bench, her dress is 'dForce', but when I simulate gravity for the dress, the rear end of it hangs 'through' the bench.

Is there a way to make the bench 'solid' so that the dress will react to it and not go right through?

Gordig

SubD is one way to do it, because dForce needs polygons to react against, and the bench may not have very many. You could also just create high-poly planes where you need the cloth to interact, then hide those when it's time to render.

denisnormandin

Gordig said:

SubD is one way to do it, because dForce needs polygons to react against, and the bench may not have very many. You could also just create high-poly planes where you need the cloth to interact, then hide those when it's time to render.

Thanks, 

I will look into that (for now I have no clue on what is SubD or hor to create high-poly planes), there is probably some tutolial about that on YouTube.
Having the right vocabulary is often the key on finding a tutorial that is relevant to a question. Without that, wrong queation can lead to a lot of hits that are not helping at all.

;)

Gordig

Create a plane using the "Create Primitive" button on your tool bar. A default plane has 24 divisions, but you can increase that, say, to 96, and it will have more polygons for dForcce to interact with. SubD is created by going to Edit -> Figure (or Object) -> Convert to SubD. Be aware that this can drastically change the shape of the object by rounding out or completely eroding edges, so it's not ideal for every situation.

denisnormandin

Gordig said:

Create a plane using the "Create Primitive" button on your tool bar. A default plane has 24 divisions, but you can increase that, say, to 96, and it will have more polygons for dForcce to interact with. SubD is created by going to Edit -> Figure (or Object) -> Convert to SubD. Be aware that this can drastically change the shape of the object by rounding out or completely eroding edges, so it's not ideal for every situation.

Thanks so much Gordig, I will try both solutions right away. SubD more out of curiosity of the possible distortions, I believe that the 'creating high-poly planes' solution will do the trick.

denisnormandin

Unfortunately, the 'creating high-poly plane' solution is not working (and I haven't gotten aroud to using SubD yet). The problem is, when I simulate, I have to start from memorized position for the dress to collide with my new high-poly plane. And even if I strip down my scene to a minimum: The lady with only the skirt on (no hair, no shirt), and the new poly-plane on the bench (bench itself turned to invisible). My simulation still take an eternity and crashes before conclusion.

So I wonder, is there a way around that?

Like editing the skirt manualy after a simulation not starting from memorized pose, so that its back pane follows the top of the bench. Or deleting that part of the clothing that is problematic?

 

The attached render is just a (very) preliminary test. But it shows what the problem is.

 

Gordig

Instead of simulating from memorized pose, do an animated simulation with frame 0 being the starting position and frame 30 (or whatever, different simulations will require different settings) being the ending position.

denisnormandin

Gordig said:

Instead of simulating from memorized pose, do an animated simulation with frame 0 being the starting position and frame 30 (or whatever, different simulations will require different settings) being the ending position.

You mean positionning her semi-standing in front of the bench at frame O and the final pose at frame 30? (or something like that)

Gordig

Yes. 

denisnormandin

Thanks, 

Now there is another problem, when I add a new pose, I can't find a way to put at the start of the timeline. The sitting woman seams to always wind up at frame 0 and the standing one at frame 30. So my animation is reversed... and that obviously doesn't solve the skirt problem. Is there a way to reverse the timeline?

Or to move frames within the timeline?

Gordig

Try saving the sitting pose as a preset, then zeroing the figure pose at frame 0 and applying the pose preset at frame 30. 

denisnormandin

Well, no success again.

The simulation starts "exploding" after a few minutes, and it's been going on for over an hour.

Gordig

Is the dress colliding with the plane or any other object before the simulation starts?

denisnormandin

No, she is standing clear of the bench, ready to sit on it, I even forgot to make the high-poly plane visible befor I started the sim (so it would have failed anyway).

I made another simulation right after that, without the clothes, only the hair visible and it ended with a firework of crazy hair. A sim for only the first frame and another for the last frame worked fine.

Now I trying with hair and skirt for the first, last and maybe one or two intermediate frames to see how it comes out. Now the bench is invisible and the high-poly plane is visible.

But I feel like I'm just waisting my time.

Maybe there is something left from my previous scene, I had a prety elaborate set with a skydome environment and a landscape and clouds and a volumetric light cube... etc.
I was happy with the relationship with the cat and the bench and the poses (and position in space). So I deleted everything except those few things to save them under another name.

Is it possible that something that is no longer listed in the scene pane couls still be there anyway and interfere (collide) with the skirt, shirt and hair during the simulation?

denisnormandin

I'm finally getting somewhere.

I found out that my Open CL device was set to my CPU instead of my graphic card. (How did that hapen, last week it was ok)

Now my simulations are back to a normal speed. The clothes reacted well to the sim... but the air still react erratically.

skinklizzard

dforce hair notoriously behaves floaty with default animation simulation.

you'll want to do your sims in two passes, run an animation sim for the dress with the hair hidden, then in the dress parameters under general >simulation set freeze simulation to on.

you can now unhide the hair and do a current frame simulation without starting from memorised pose, just to drape the hair in place.

if you find clothing sims exploding, ensure that your pose/animation doesn't have the underlying figure clip with itself, a hand touching a leg with the finger slightly clipping into the leg might look fine, but if there is cloth trying to simulate and colide with both stuck between them it can rapidly increase force on the vertices until it finds a position with no clipping (i.e. low satelite orbit) and explode your mesh.

increasing the frames per second multiplier or the collision iterations under quality in the simulation settings pane can help reduce explosions too.

denisnormandin

Thanks Skinlizzard,

I will copy those notes for future uses.

I didn't know about the Freeze simulation option, and since I didn't need the animation sequence, I just hid the clothes to do a sim only on the last frame. (Without the memorized posed option)

Thanks to you and Gordig, I'm ready to go to the next phase of my project.