UE4 My skeletal mesh won't simulate physics when in a socket - unreal-engine4

I am making a scale with chains that hold a plate.
The Scale Asset
I have the chain as a skeletal mesh with a physics asset. The part that the chains hang onto have sockets.
The chain
When I try to attach my chain to the asset, I have issues:
1) When I put the chain into the blueprint actor and assign it to its parent socket via the details panel...the chain will just fall off when simulated rather than hanging from where the socket is.
2) When I attach the chain to a socket via blueprints, the physics won't simulate at all. The chains just stay rigid.
example of the construction script
How can I get the chains to stay in place...while simulating physics?
Is there a better way I am just not using?
Thank you.

On your chain, in the physics asset, you need to select the physics capsule on the bone that is attaching to the socket and set it’s physics from default/simulating to kinematic. It disables physics on that one bone and will anchor instead of fall when you attach it.

Related

How to add force to an actor in unreal engine?

I am using blueprints. I have an actor that I want to move using a physics force/impulse when they are spawned. Basically I want to push the actor when they are spawned. I have physics and gravity enabled.
Use the add impulse, or add force nodes.
Add impulse is designed to be used only once to add a burst at a location.
E.g hitting a golf ball.
Add force is designed to be used multiple times to gradually move objects.
E.g Player pushing a heavy cube
Use whichever is best suited for your needs.

Unity physics scenes copy all colliders from main scene

I am trying to use Unity's physic scenes to perform some simulations outside of the main scene. That being said, I need all of the colliders from the main scene in the physics scenes. What is the easiest way to create a physics scene with all of the existing colliders from another scene? Do I have to loop through everything, use SceneManager.MoveGameObjectToScene(...) for every object then move them back at the end of the simulation? This doesn't seem scalable.
EDIT
I have a multiplayer game, when I get responses from the server I am taking their velocity and the servers position, then applying all local movement since that packet was sent via Physics2D.Simulate() to have the velocities correctly applied to the position. Now I need to do the same for the projectiles so I would need the map colliders as well as the player's. I was reading the best thing to do for physics sims is use physic scenes. If I call Physics2D.Simulate() in the main scene for more than 1 set of data (player movement vs projectiles) places I got a lot of screen jitter. Moving these simulations into separate scenes removes the jitter.
The only alternative I see is re-implementing Physics2D.Simulate() myself which seems like a bad (and complicated) idea.
Thanks.
I ended up only needing the collider and rigid body so I created an empty object in the physics scene with these 2 objects. Every time I needed to run the simulation, I would update the rigid body with the current players rigid body details then run the sim and apply the output velocity from the sim to the players rigid body again.

Rigidbody2D or raycasting?

I am working on a 2D game that involves many blocks that stack and collide on eachother and the player. I am currently using Rigidbody2D on the blocks for dynamic collisions but I am not a fan of how the dynamic physics include the "bounciness" in the elastic collisions. Also, there is an inherent push-force as well as other unfavorable push physics that are too "realistic".
I am wondering what is the best way to handle my predicament to remove the bounciness and push elements of the rigid bodies. I've tried adjusting the block's masses and bounciness physics but no luck. Is there a way to set them all as kinematic or disable these realistic effects somehow and still have them collide via rigidbodies? (Kinematic would be great if they were able to collide with each other) Or will I have to create some sort of raycast based block physics handling script? Or is there an even better solution to creating this very primitive physics structure that I am not seeing?
Thanks for any and all help!
The only way I could think of solving your problem, such that you have complete intuitive accuracy, is to write your own Rigidbody controller. Of course you can still reuse the Box colliders.
Once you've decided on a collision detection method and manifold generation working (raycasting maybe), this link details the impulse resolution you need.

Make two physics objects not collide but do detect collisions in Unity

I have a Unity project in which there is a 2D game world that consists of static colliders to make the geometry solid to the characters that inhabit it. The player is a dynamic collider (with a non-kinematic rigidbody). There's also an enemy character that is also a dynamic collider. Both characters walk over the floor and bump into walls like I'd expect them to.
What I want to achieve is that the player and enemy are not solid to each other, so they can move through each other. I achieved this by putting the enemy and the player on separate layers and setting the collision matrix so that these layers do not collide with each other. The problem I'm having now, however, is that I do want to detect whether or not the enemy and the player ran into each other. I added a trigger collider to the enemy character, it's on the enemy layer which means it doesn't detect collisions with the player.
I thought of making a sub-gameobject for the enemy, put it on the player's layer, add a rigidbody and trigger collider to it and use that to detect collisions between the player and the enemy, but it feels so convoluted that it leaves me wondering if there isn't a more elegant solution for this.
Edit (2020-05-26): Nowadays you can tell the engine to ignore collisions between two given objects. Kudos to Deepscorn for the comment. Will leave the rest of the answer unchanged, and read with that in mind.
Yes, you need to create a child GameObject, with a trigger collider, and put it in a layer that interacts with the player layer.
No, you don't need to add a Rigidbody to the new GameObject, the parent's rigidbody already makes it a dynamic collider, so you will get OnTrigger events.
As a side note, just to keep things organized, if you create a child of the enemy don't put it in the player layer. For example, in the future you might need to disable the player's layer collision with itself. Furthermore, if your player interacts this way with many objects, I'd put a single trigger on the player instead of the enemies, on a separate PlayerTrigger layer, just to keep things simple.
Isn't there a simpler way? Not really. You definitely need non-interaction between the player and enemy colliders, but some kind of interaction between them too. So one of them needs to span two layers, or the whole interaction would be described by a single bool. The physics engine processes lots of information in one go, so you can set all the layers and collisions you want, but during the physics loop you have no further control on what happens. You can't tell the engine to ignore collisions between just two objects. Having only 32 layers, and having them behave in the rigid way they do are actually heavy optimizations. If you are concerned about performance for creating another layer, disable interaction between layers you don't need, like the trigger layer and the floor and walls, or layers that don't even touch.
Your alternative is doing it all by code, which is even less elegant. A single child capsule on the player doesn't sound that bad now, doesn't it?

2D physics on game object made up of components

Say you want to let your users create a 2D airship (side view) made up of components. One component could be a floating balloon, another could be a storage room, etc.
And say you want this airship to have physics applied to it as a whole, with each component playing a part in this. For example, balloons would take away from its down force and other compartments would apply down force to it.
At the same time, the whole airship works as a whole (or at least the only physical separation would be between floater components and the others, which apply weight), so physics are applied to it as if it was one body.
Now, how can this be managed? How can I customize a game object via a script, giving it different components with different weights, and have it behave like it was a single premade object?
I'm sorry if the question is simple, but I'm only getting started with unity. Thank you very much!
TL;DR: Customizable airship gameobject with different components that have different weights. How to make it behave as a single physics entity and manage its different components?
I'm not sure that I completely understood the question :D
You mean having a game object, that has some child game objects, each with individual Collider and Rigidbody, and the Rigidbody physics applied to the parent game object? You can use joint colliders for this purpose such as HingeJoint2D, and set the parent's Rigidbody as ConnectedRigidBody.
(And instead of the word "component", use child or part or sth else to prevent ambiguity. 'Cuz the components in Unity3D are stuff like scripts, rigidbody, collider, etc. which are attached to game objects.)