23-07-2020, 10:56 AM
Hello,
I've been trying to make a grapple gun with physics that are intuitive and at least somewhat realistic. I found your rope tech demo and figured it would be exactly what i need, however, i've been having trouble getting it to behave the way i want to, and have even had a few instances of it launching rigid bodies several orders of magnitude away from the game space.
So to start off, my basic set up was a rope connected to a rigid body and a nonRigidBody collider, i have a ObiRopeCurser set to 0,0,true IIRC and a script that runs Cursor.changeLength(rope.restLength +/- K*time.deltaTime) dependent on the player input. After a little bit of trouble shooting i got the correct attachment components and got a basic pendulum working. However the rope was extremely bouncy and stretchy, furthermore pressing the inputs seems to cause the rope to clump up near the beginning before the solver can find a solution where they're better spread out, but in doing so it will add a lot of kinetic energy to the rope, and cause the pendulum to flail about in a completely unstable fashion. Trying to reel the rope in has a different effect, it will make a ton of tension where the rope particles are being eaten, which seems to build up energy for a moment, until it reaches the other side of the rope where the rigid body is, in which time it will launch the rigidbody at an high speeds towards where the rope cursor is. Even if i just tap the reel in key, it will barely change the rope length, but the rigid body will still get launched.
At this point i remembered the tether component from the pendulum video, and how easy, intuitive, and just overall effective it was at achieving its purpose, but in looking for a way to implement it, i found that its interface has changed massively. All of the previous options replaces with a standardized few. Ive been playing around with it for awhile now, but with the few options provided in the solvers constraint menu i wasn't able to make any noticable change in its stiffness. i've tried a host of other options including increasing the rope thickness, changing the materials/template values, disabling/tweaking the other constraints in a massive variety of ways, increasing the number of substeps & enabling the unity physics substep option, increasing dampening, bend/stretch settings in the rope instance, changing where i put the rope cursor, and i've honestly no idea where to go from here.
Ive seen here on the forums its often recommended to increase the iterations (for the tether constraint) and substep count, but increasing the iterations doesn't seem to have any noticeable effect, and enabling the unity physics substeps and increasing the substep count will change the phsyics of the world in a way that makes it unusable (character jumps significantly higher, walk speed massively decreased, etc). Also it crashed 3 different times last night, i'd happily provide the crash reports if i can access them. But for right now, i'm looking into other options. I would love to use your ropes the way they're shown in your videos, i bet they would make a fantastic harpoon/tether grapple gun, but as of yet, i'm not able to recreate what i've seen.
An album of some short 30 second videos of my setup: https://imgur.com/a/z4aaDqs
I've been trying to make a grapple gun with physics that are intuitive and at least somewhat realistic. I found your rope tech demo and figured it would be exactly what i need, however, i've been having trouble getting it to behave the way i want to, and have even had a few instances of it launching rigid bodies several orders of magnitude away from the game space.
So to start off, my basic set up was a rope connected to a rigid body and a nonRigidBody collider, i have a ObiRopeCurser set to 0,0,true IIRC and a script that runs Cursor.changeLength(rope.restLength +/- K*time.deltaTime) dependent on the player input. After a little bit of trouble shooting i got the correct attachment components and got a basic pendulum working. However the rope was extremely bouncy and stretchy, furthermore pressing the inputs seems to cause the rope to clump up near the beginning before the solver can find a solution where they're better spread out, but in doing so it will add a lot of kinetic energy to the rope, and cause the pendulum to flail about in a completely unstable fashion. Trying to reel the rope in has a different effect, it will make a ton of tension where the rope particles are being eaten, which seems to build up energy for a moment, until it reaches the other side of the rope where the rigid body is, in which time it will launch the rigidbody at an high speeds towards where the rope cursor is. Even if i just tap the reel in key, it will barely change the rope length, but the rigid body will still get launched.
At this point i remembered the tether component from the pendulum video, and how easy, intuitive, and just overall effective it was at achieving its purpose, but in looking for a way to implement it, i found that its interface has changed massively. All of the previous options replaces with a standardized few. Ive been playing around with it for awhile now, but with the few options provided in the solvers constraint menu i wasn't able to make any noticable change in its stiffness. i've tried a host of other options including increasing the rope thickness, changing the materials/template values, disabling/tweaking the other constraints in a massive variety of ways, increasing the number of substeps & enabling the unity physics substep option, increasing dampening, bend/stretch settings in the rope instance, changing where i put the rope cursor, and i've honestly no idea where to go from here.
Ive seen here on the forums its often recommended to increase the iterations (for the tether constraint) and substep count, but increasing the iterations doesn't seem to have any noticeable effect, and enabling the unity physics substeps and increasing the substep count will change the phsyics of the world in a way that makes it unusable (character jumps significantly higher, walk speed massively decreased, etc). Also it crashed 3 different times last night, i'd happily provide the crash reports if i can access them. But for right now, i'm looking into other options. I would love to use your ropes the way they're shown in your videos, i bet they would make a fantastic harpoon/tether grapple gun, but as of yet, i'm not able to recreate what i've seen.
An album of some short 30 second videos of my setup: https://imgur.com/a/z4aaDqs