3D Grappling Hook!

YoloJoe · Feb 8, 2016

Hello everyone! I would love to add a grappling hook to my game but I have no idea on where to start. There does not seem to be ANY tutorials anywhere on making a 3D grappling hook.
I found this thread but it's 6 years old and after testing it it does not seem to work anymore. Does anybody know about or have a working 3D Grappling hook script? If not, can we create one together?

Cheers!

GroZZleR · Feb 8, 2016

What kind of grappling hook? The kind you look at a point, click to use and it just drags you towards that point... or something more complex?

YoloJoe · Feb 8, 2016

GroZZleR said: ↑

What kind of grappling hook? The kind you look at a point, click to use and it just drags you towards that point... or something more complex?
Click to expand...

If not too hard, I would love to be able to use it as a rope with physics and when I press RMB it drags me towards the anchor point.. But I would have to start somewhere, so a click and drag system would be more than good enough for now!

Magnumstar · Feb 8, 2016

I think the best method to do this would be have mouse click while in hook mode add velocity on hook in the direction of click using camera.main.screenpointtoray. if it hits a collider with an acceptable tag (layer mask)(wall to hook on), then set grapple hook velocity to 0 to stop it in its tracks and apply the same velocity to your attached player to repel him towards the hook.

i have no pre made example sorry

YoloJoe · Feb 9, 2016

Magnumstar said: ↑

I think the best method to do this would be have mouse click while in hook mode add velocity on hook in the direction of click using camera.main.screenpointtoray. if it hits a collider with an acceptable tag (layer mask)(wall to hook on), then set grapple hook velocity to 0 to stop it in its tracks and apply the same velocity to your attached player to repel him towards the hook.

i have no pre made example sorry
Click to expand...

How would I go about making the grapple stick to what it hits?

Josenifftodd · Feb 9, 2016

YoloJoe said: ↑

How would I go about making the grapple stick to what it hits?
Click to expand...

You could make an object which has a pivot at the top of the hook as a sensor , make a box collider on the hook sensor (maybe use a flat plane as sensor) and then make it so when the box collides with whatever you want to hook to the hooks new position is the hookspot. thats how I'd do it, you may want to use a raycast as well...

YoloJoe · Feb 9, 2016

Josenifftodd said: ↑

You could make an object which has a pivot at the top of the hook as a sensor , make a box collider on the hook sensor (maybe use a flat plane as sensor) and then make it so when the box collides with whatever you want to hook to the hooks new position is the hookspot. thats how I'd do it, you may want to use a raycast as well...
Click to expand...

Wouldn't raycast shoot the hook instantly? It would be cool to make the effect of the hook going through the air. To see it fly through the air.

Josenifftodd · Feb 9, 2016

YoloJoe said: ↑

Wouldn't raycast shoot the hook instantly? It would be cool to make the effect of the hook going through the air. To see it fly through the air.
Click to expand...

Thatd probably be done with an animation then and obviously the grip could only be used from a distance because of the animation being a certain amount of time. I think not sure, wouldn't dare try make one, id fail haha I just kinda understand how you'd do it.

YoloJoe · Feb 12, 2016

Ok, so I'm now shooting the prefab, it has a tail renderer (I don't know if this is the best way to draw a line between the player and the hook) and it sticks to what it hits. Still don't really now how to drag the player towards the hook..

YoloJoe · Feb 12, 2016

I found this on Reddit:

[Text Tutorial] 3d variable-length rope grappling hook!

After far too much time searching and searching for solutions, I finally figured out how to make a 3d grappling hook. I've noticed quite a few people showing interest in grappling hooks recently, so I figured I'd share the information I found.

Basically, I have a script, HookController, attached to my player GO. This script handles all the hook logic, the raycasting, and its various states (fired, hooked, resting, etc.). The hook logic is all pretty simple (raycasts, checking raycastHits, etc.) so I won't get into that. Within this script, I have a private ConfigurableJoint variable called hookShot. hookShot is assigned a new ConfigurableJoint in a CreatJoint() function, which is added to my player reference. You can set up your own x, y, zDrives if you'd like, it doesn't matter too much to the core of the mechanic. Key settings of the ConfigurableJoint are listed below:

linear limit - basically the rope length; constrains distance between parent component and the attached rigid body to some value

xMotion - this can be set to ConfigurableJointMotion.Limited, .Free, .Locked. Limited limits the motion (who'd have thought...) to whatever linear limit and drive settings you set. To achieve variable length rope, this MUST be limited.

yMotion, zMotion - same as xMotion.

enableCollision - enables collision of the joint itself, NOT the rope; that can be achieved with additional raycasts though

targetVelocity - a specified velocity you want the object (player, in my case) to achieve; this velocity is achieved with the x, y, zDrive forces.

targetPosition - a position you want the object (player) to move towards, using the target velocity;

connectedBody - whatever object your raycast hits; I pass a hitBody RigidBody variable to my CreateJoint function, which is found in raycastHitVariable.rigidbody;

connectedAnchor - the MOST important part of the hook, in my opinion; the start of the hook is the location on/in whatever object the hook is created on (again, player in my case), the other end of the hook is the connectedAnchor. connectedAnchor is a Vector3; this Vector3 is found on the connectedBody of the ConfigurableJoint. HOWEVER, accessing the connectedBody's transform.position returns a LOCAL Vector3; you have to do a connectedBodyReference.InverseTransformPoint(rayCastHitVariable.point) to set the end of the grappling hook's coordinates to world coordinates.

Feel free to ask questions if something is unclear. I'll respond as soon as I can, thought it might not be for several hours or a day. I hope this helps some people in the future; I wish something like this existed when I first started!
Click to expand...

But I have no idea how to implement the information into a script... ?

GumDev · Feb 22, 2023

my grapple hook shoots but doesn pull me

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3D Grappling Hook!