How to build a deformable rigid?

[feitang]

Hi, there

I just wanna build a deformable rigid, like a barrel, as shown in this video https://youtu.be/-qaQETsXeWA (0:27s).

I didn't find this kind of information in the User Manual.

Thanks in advance.

Fei

[josemendez]

Hi, there

I just wanna build a deformable rigid, like a barrel, as shown in this video https://youtu.be/-qaQETsXeWA (0:27s).

I didn't find this kind of information in the User Manual.

Thanks in advance.

Fei

Hi,

Here's the relevant manual page:
http://obi.virtualmethodstudio.com/manua...aints.html

This behavior is called plasticity. When deformed, plastic materials absorb part of the deformation into their rest shape. You can control the plastic behavior using plastic yield, creep and recovery parameters, see the above link for details.

kind regards,

[feitang]

Hi,

Here's the relevant manual page:
http://obi.virtualmethodstudio.com/manua...aints.html

This behavior is called plasticity. When deformed, plastic materials absorb part of the deformation into their rest shape. You can control the plastic behavior using plastic yield, creep and recovery parameters, see the above link for details.

kind regards,

Hi, Josemendaz,

Thanks for your quick reply. I have encountered another problem, and I am really confused about it. 
I set the ball and barrel with plastic yield 0.2, and build a hand model to grasp them. however, when I start the simulation, the ball and barrel immediately shrank, as the attached video shows.
I don't know how to fix this problem. Could you help me?

kind regards,
Fei

[josemendez]

Hi, Josemendaz,

Thanks for your quick reply. I have encountered another problem, and I am really confused about it. 
I set the ball and barrel with plastic yield 0.2, and build a hand model to grasp them. however, when I start the simulation, the ball and barrel immediately shrank, as the attached video shows.
I don't know how to fix this problem. Could you help me?

kind regards,
Fei

Hi,

That means the plastic yield is too large, and the softbodies just crumple under their own weight.

Either spend more substeps on the simulation to make the softbodies more rigid, or reduce the plastic yield.

kind regards,

[feitang]

Hi,

That means the plastic yield is too large, and the softbodies just crumple under their own weight.

Either spend more substeps on the simulation to make the softbodies more rigid, or reduce the plastic yield.

kind regards,

Hi, josemendez,

I set the plastic yield with 0, but the shrink also occurs. It is confused.

[josemendez]

Hi, josemendez,

I set the plastic yield with 0, but the shrink also occurs. It is confused.

Make sure the scale of your transform and the scale of your blueprint are correct. Otherwise the softbody will instantly shrink/expand upon being simulated, because the scale of visuals and physics don't match.

Check the RubberDragon sample scene for a setup example: the Dragon softbody object has a scale of 2 in all axis, the Dragon blueprint has a scale of 2 as well.

kind regards,

[feitang]

Make sure the scale of your transform and the scale of your blueprint are correct. Otherwise the softbody will instantly shrink/expand upon being simulated, because the scale of visuals and physics don't match.

Check the RubberDragon sample scene for a setup example: the Dragon softbody object has a scale of 2 in all axis, the Dragon blueprint has a scale of 2 as well.

kind regards,

Very useful information! It does work! 

I encountered a new problem. I built a VR hand in the scene, which is a rigidbody, but how to make a collision with the softbody?
I put the rigid hand under the obi solver, and also added the obi collision to the VR hand, but it didn't work. 

look forward to your reply!

   

[josemendez]

Very useful information! It does work! 

I encountered a new problem. I built a VR hand in the scene, which is a rigidbody, but how to make a collision with the softbody?
I put the rigid hand under the obi solver, and also added the obi collision to the VR hand, but it didn't work. 

look forward to your reply!

Hi,

Make sure that:
- Collision constraints are globally enabled in your solver.
- Collision filters are properly set up. See: http://obi.virtualmethodstudio.com/manua...sions.html

Note that Obi is a particle-based engine, which means that regular Unity collision callbacks (OnCollisionEnter/Exit, etc) and collider-based functionality (contact callbacks, raycasts, etc) don't work. Obi has its own collision detection pipeline, and its own collision callbacks / queries. See: http://obi.virtualmethodstudio.com/manua...sions.html
http://obi.virtualmethodstudio.com/manua...eries.html

kind regards,

[feitang]

    josemendez pid='15040' dateline='1698843778']
Hi,

Make sure that:
- Collision constraints are globally enabled in your solver.
- Collision filters are properly set up. See: http://obi.virtualmethodstudio.com/manua...sions.html

Note that Obi is a particle-based engine, which means that regular Unity collision callbacks (OnCollisionEnter/Exit, etc) and collider-based functionality (contact callbacks, raycasts, etc) don't work. Obi has its own collision detection pipeline, and its own collision callbacks / queries. See: http://obi.virtualmethodstudio.com/manua...sions.html
http://obi.virtualmethodstudio.com/manua...eries.html

kind regards,

Hi, 

I carefully read the links you provided, and I think the two conditions are guaranteed, as shown in the attached figures. 
It is very confused why it doesn't work.

       

[josemendez]

Hi, 

I carefully read the links you provided, and I think the two conditions are guaranteed, as shown in the attached figures. 
It is very confused why it doesn't work.

Hi,

The attached figures don't show the status of either condition. The first one shows that "particle collision & queries" are enabled, but the status of "collisions" is not shown in the image. They're right below the visible portion of the scrollview.

particle collisions ---> collisions between particles.
collisions ---> regular collisions against colliders.

The second screenshot shows the collision filters of the collider, but not the collision filters of the softbody. There are set per-particle in the softbody blueprint editor.

kind regards,