Help Dynamic attachment to fixed object with hinge component

[NoahAtlas]

Hi!

The most probable cause for this is the rope colliding with the hook. This will lead to an impossible to solve situation, as the rope can't simultaneously intersect the collider (what the attachment strives to achieve) and not intersect the collider (what collisions strive to do). As a result, the simulation will shake/jitter as it attempts to meet both conditions in vain.

This is described in the manual, along with potential solutions. See "attachments inside colliders": https://obi.virtualmethodstudio.com/manu...ments.html


I think you're confusing chain constraints with chain rendering, which is a completely different thing. Chain constraints are only used by rods. Ropes (regardless of how you render them) use distance constraints.


I think you refer to stress, not strain? Strain = deformation due to stress. So what you actually want is to have as little strain as possible, that is, stress forces must not deform the rope but instead rotate the hook. To achieve this, stretch compliance must be set to zero (since compliance = elasticity). Any other setting will take you further from your goal.

let me know if I can be of further help,

kind regards,

Hi and thanks for the quick reply!

The most probable cause for this is the rope colliding with the hook. This will lead to an impossible to solve situation, as the rope can't simultaneously intersect the collider (what the attachment strives to achieve) and not intersect the collider (what collisions strive to do). As a result, the simulation will shake/jitter as it attempts to meet both conditions in vain.

I also thought this might be the issue but to my understanding my collider should be setup properly where that should not be the reason why. In the attached image "Collider" you can see my setup for which I had followed the manual (perhaps I misunderstood something? It looks ok to me).

I think you're confusing chain constraints with chain rendering, which is a completely different thing. Chain constraints are only used by rods. Ropes (regardless of how you render them) use distance constraints.

Apologies, this is just as a result of my poor wording. I'm aware of the difference, as I have read that part in the manual. I was just referring to all the constraints of my rope which is rendered as a chain.

I think you refer to stress, not strain? Strain = deformation due to stress. So what you actually want is to have as little strain as possible, that is, stress forces must not deform the rope but instead rotate the hook. To achieve this, stretch compliance must be set to zero (since compliance = elasticity). Any other setting will take you further from your goal.

Apologies for this misnomer as well. You are right, I do not want the rope to stretch. In the beginning of the scene the rope should be as stretched as it will ever be, as the top hook is in the highest position. In this position the bottom hook should be angled upwards toward the top hook due to the rope being attached to both. When the top hook is moved down I want the bottom hooks to also rotate down with it in a realistic manner due to the chain no longer experiencing as much stress.

Removing the stretch compliance sadly does not fully fix the attachment not properly attaching to the bottom hook as seen in image "Attachment issue". It clearly has the attachment as it is angled towards it but its just too far away. I'm not sure how to fix this.