Help Mesh intersection through cloth and not getting perfect simulation on character cloth

[Himanshu]

Hi josemendez,
I am unable to fix mesh intersection issue on runtime as you can see below in those screenshot i have uploaded
I just created custom collider on character to make it right but it doesn't work at all and not getting good physics simulation as well.
Please help me out...

[josemendez]

Hi josemendez,
I am unable to fix mesh intersection issue on runtime as you can see below in those screenshot i have uploaded
I just created custom collider on character to make it right but it doesn't work at all and not getting good physics simulation as well.
Please help me out...

Hi,

- What is your collider setup? What do you mean by "custom collider"?
- What are your solver collision settings?
- Are you using cloth proxies?
- Are you using skin constraints?
- Are you simulating in world or local space?

[Himanshu]

Hi,

- What is your collider setup? What do you mean by "custom collider"?
- What are your solver collision settings?
- Are you using cloth proxies?
- Are you using skin constraints?
- Are you simulating in world or local space?

Hi Josemendez,

-I am using capsule collider on character..
-For Solver collision setting i used same setting that was in character cloth example.
-Yes i am using cloth proxies..
-No i am not using that because of that i am not getting good physics simulation "The cloth won't move if i am using that."
-Yes i am simulating in local space and it has these setting "World Linear  Velocity-0.5,Wolrd Angular velocity-0.8 and world linear and angular inertia scale =1"

I am uploading some screenshot of collider you can get better idea what's happening here!!
Is, it possible my cloth and character should refers same rig bones so, afterward i can able to resize cloth according to my collider but should it be work on runtime?.

Thanks for your response!!

[Himanshu]

Hi Josemendez,

How can i make it work..
Please help me out anyone!

Thanks.

[josemendez]

Hi Josemendez,

How can i make it work..
Please help me out anyone!

Thanks.

Hi,

How is your proxy set up? how many skin channels are you using, and what parts of your mesh are being skinned to the simulated particles?

Using skin proxies incorrectly can result in weird-looking sims, very similar to what you show here, because automatic skinning cannot bind every vertex automatically (that's why skin channels must be used to guide the skinning process). Try with a simpler simulation first (non using any proxies) just to make sure the basic simulation setup is correct, then add proxy skinning on top of it once you're sure the base simulation works as intended.

[Himanshu]

Hi,

How is your proxy set up? how many skin channels are you using, and what parts of your mesh are being skinned to the simulated particles?

Using skin proxies incorrectly can result in weird-looking sims, very similar to what you show here, because automatic skinning cannot bind every vertex automatically (that's why skin channels must be used to guide the skinning process). Try with a simpler simulation first (non using any proxies) just to make sure the basic simulation setup is correct, then add proxy skinning on top of it once you're sure the base simulation works as intended.

Hi,

Thanks for your response,
Yeah! i just removed proxy now it's better but still getting mesh intersection and after using skin constraint i am not getting good simulation like character cloth example had.
as you can see below Screenshot i have attached "Bad Simulation, Mesh Intersection". 
-Without skin constraints i am getting simulation like smooth but the cloth fall down after a while, Basically collider isn't working on cloth that character worn as you can see below Screenshot i have attached "Without Skin Constraints and 02". 

-Would you like to suggest me what solver and obi cloth setting should i use, currently i am using these setting as you can see in below screenshot:-" SolverSetting".
In Obi cloth setting i am using Distance and Skin constraint both has 1 stiffness,0.5 slack etc.

<Skin Constraint setting.......................
Mass=0.1
Radius=0.03
Phase=3
Skin-radius=0.001
Skin-Backstop-radius=0.5
skin-backstop=0
skin-stiffness=0.1
......................>
This is the setting i am using in the current project..
I have been working on obi cloth since 20 days ago so please,  If anyone can suggest and help me out, that would be grateful..

Thankyou very much for all of this....

[josemendez]

Hi,

Thanks for your response,
Yeah! i just removed proxy now it's better but still getting mesh intersection and after using skin constraint i am not getting good simulation like character cloth example had.
as you can see below Screenshot i have attached "Bad Simulation, Mesh Intersection". 
-Without skin constraints i am getting simulation like smooth but the cloth fall down after a while, Basically collider isn't working on cloth that character worn as you can see below Screenshot i have attached "Without Skin Constraints and 02". 

-Would you like to suggest me what solver and obi cloth setting should i use, currently i am using these setting as you can see in below screenshot:-" SolverSetting".
In Obi cloth setting i am using Distance and Skin constraint both has 1 stiffness,0.5 slack etc.

<Skin Constraint setting.......................
Mass=0.1
Radius=0.03
Phase=3
Skin-radius=0.001
Skin-Backstop-radius=0.5
skin-backstop=0
skin-stiffness=0.1
......................>
This is the setting i am using in the current project..
I have been working on obi cloth since 20 days ago so please,  If anyone can suggest and help me out, that would be grateful..

Thankyou very much for all of this....

Hi,

Are you relying on colliders (arms, torso, etc) for the cloth to stay on the character? If so, sorry but that's not the way character clothing works (not in Obi, not in any other existing engine). In realtime applications, time discretization causes tunneling issues that just cannot be solved robustly. That's why character cloth is done by blending animation and simulation together, avoiding colliders when possible.

If you look closely at the CharacterCloth sample scene, you'll see that all particles from the waist up are fixed, and follow character animation. No simulation is performed for them. Then, particles below the waist line are simulated, and collide with the character's legs. However the whole thing does not use colliders to keep the cloth onto the character.

Generally you have some fixed particles that follow the skinned animation of the cloth (around the waist, shoulder, arms, etc), then unfix particles in zones that you want to simulate. The fixed particles make the cloth stay in place relative to the character, then you can use skin constraints to control how animation and simulation blend together.

[Himanshu]

Hi,

Are you relying on colliders (arms, torso, etc) for the cloth to stay on the character? If so, sorry but that's not the way character clothing works (not in Obi, not in any other existing engine). In realtime applications, time discretization causes tunneling issues that just cannot be solved robustly. That's why character cloth is done by blending animation and simulation together, avoiding colliders when possible.

If you look closely at the CharacterCloth sample scene, you'll see that all particles from the waist up are fixed, and follow character animation. No simulation is performed for them. Then, particles below the waist line are simulated, and collide with the character's legs. However the whole thing does not use colliders to keep the cloth onto the character.

Generally you have some fixed particles that follow the skinned animation of the cloth (around the waist, shoulder, arms, etc), then unfix particles in zones that you want to simulate. The fixed particles make the cloth stay in place relative to the character, then you can use skin constraints to control how animation and simulation blend together.

Hi,

Thanks to response quickly,
Yes i am totally agree on that, but i am working on app that has an avatar as a character who can wear different three kind of size clothes like small, medium and large. when i try to set to large the cloth then it should come out from character and if it is small then the cloth should be tore from top to bottom. 

Please tell me if is it possible to do....
I think i have done almost 60% i am able to increase the size of the cloth using distance constraint ,but it's not working with small cloth.
Do you have any idea about how can i do it that would be great appreciate..

Thankyou,

[josemendez]

Hi,

Thanks to response quickly,
Yes i am totally agree on that, but i am working on app that has an avatar as a character who can wear different three kind of size clothes like small, medium and large. when i try to set to large the cloth then it should come out from character and if it is small then the cloth should be tore from top to bottom. 

Please tell me if is it possible to do....
I think i have done almost 60% i am able to increase the size of the cloth using distance constraint ,but it's not working with small cloth.
Do you have any idea about how can i do it that would be great appreciate..

Thankyou,

Nope, that's not doable in realtime. You might get better results by using a smaller timestep (or increasing the amount of solver substeps), but this is way too ambitious a goal for realtime character clothing.

[Himanshu]

Nope, that's not doable in realtime. You might get better results by using a smaller timestep (or increasing the amount of solver substeps), but this is way too ambitious a goal for realtime character clothing.

Thanks a lot but i want to ask one more thing that, is it possible to access skin radius, skin backstop and skin backstop radius on runtime?
I am able to increase the size of the cloth using distance constraints, but unable to make them smaller... 
If is there anything to make it right please suggest me i will try to figure out something from them 

Thanks a lot,