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huge

bullet custom deformable metal constraint

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Hi everyone, 

I made this setup to mix constraints between conetwist and glue, depending on angle value,

i set the constraint_name in a sop solver plugged in the constraint network node, it works quite well

but the resulting object is floating in the space... is anobody here can check my file and tell me what's going on!!!?

apparently its not a subsanple or CFM, ERP issue ( i checked all this parameters and, nothing...)

thx by advance, 

Best regards

 

H

TEST_PACKED_CONST_METAL_V002.hip

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Hi Jaulin,

By "

On 1/30/2017 at 3:32 PM, huge said:

but the resulting object is floating in the space... is anobody here can check my file and tell me what's going on!!!?

" do you mean the metal pad in your scene? Do you mean that you want the metal pad to be staying in place?

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yep, the metal pad is floating, and i want it to stay in place!

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opss. glue constraints not connected to static geo. I don't understand your network but this basic setup can help you :)

static .hipnc

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Hi Huge,

 

Sorry for the late response... I think the problem is that probably you should have some static object and mark it as inactive, then have the parts not reacting to the ball on the pad glue to the object with strength = -1; Hope this helps!

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Hi guys!

thanks for responding, 

@birko don't understand what you want to show in your scene...it's just a basic scene with glue!!! I try to develop something to switch between conetwist and glue on a per-point basis, to mimic plasticity behaviour with bullet.

@violalyu, not sure to really understand what you are talking about, can you upload an example scene?

btw thx to you both to take time to help me!!!

 

cheers

 

 

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Interesting that you made the hard part but is struggling with the easy one! 

All constraints work the same, a primitive connecting pieces of geometry. This means that to make you plate stay in place, you need to "anchor" it to something. 

One way I like to do it is to connect the primitives you want to stay in place to a single point by using an assemble sop to pack your original plate (I also moved the point a little bit to the back, so it's easier to see), before the fracture

Like this:

rljP5jT.png

In the picture above only the pieces on the edges are setup to not move

Then you can create another con. network insides DOPS (or not, you can use the same too, just pay attention to the names) and use this new con. to glue your object to a single inactive point (the packed one) 

Like this

5k0Yo3n.png

And the rest you already did

z9ciMNL.png

 

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Hi vtrvtr!

thx for your answer,

but when i mean floating, I don't want to attach the metal patch to something, it's free and flying away after the collision with the box and i'm ok with that,

the problem is that the pad dosen't stop at all, and floating slowly in space longtime after the dynamic occur.like the gravity dosen't affect it... this is an artefact and i don't understand what's appen!!!

play the sim 200 frames and see what's appen

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Oh, I see.

 

 I think that's because the collision padding was set to 0 and the object is too light (low density). Less means more precise with col. padding, but I don't think you can set that to zero (although I might be wrong here). With 0.001 col. p. and 2000 density it looks like this:

pD8n7Fa.png

I cropped it, but this frame 220 of your original file 

Edited by vtrvtr
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Hi vtrvtr,

I don't think it's a padding collision or density issue, 

I set it like you said and i can notice the same floating behaviour of the pad 

be carrefull between frame 80 and 150 it is obvious that the pad is floating it is damped because the box is on top of it, but still floating...

I think it is more a constraint solver issue than a bullet setings prob

Thx ;)

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Hi Huge,

In this case I think you can try the RBD autofreeze or wire in a geometry wrangle in the solver as a pre-solver and force it to slow down after a certain frame, e.g. @v *= 0.8;  and also the angular velocity @w , and have it stop completely when it's length is less than a certain value.

 

Hope this helps!

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hey everybody,

I found a solution for the floating bug occuring in my setup!

seems that if i substep the bullet solver by 1 and substep the dopnet to 10 it's ok!

don't understand exactly what's going on...anybody?

TEST_PACKED_CONST_METAL_V002_FIXED.hip

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