Resolved Rotating only my gameObject parent

Hi all,

I'm learning the ways of Unity.

The context is that I created 2 cylinder primitives and created an object in the letter 'T'. I created my object as a prefab and the base of the 'T' is my parent on the top is a child. Now within my update function when I simply call transform.rotate(...) my newly constructed 'T' rotates.

My issue is when I want RigidBody.AddTorque(...) to my 'T' only the base rotates. Why doesn't it rotate as a whole? What do I need to do so it behaves as one complete object rotating?

Thanks and if I figure it out myself I'll post my solution.

 

Perhaps because of where you put the Rigidbody that you're adding torque to. Here's how to track down what's going on:

You must find a way to get the information you need in order to reason about what the problem is.

What is often happening in these cases is one of the following:

- the code you think is executing is not actually executing at all
- the code is executing far EARLIER or LATER than you think
- the code is executing far LESS OFTEN than you think
- the code is executing far MORE OFTEN than you think
- the code is executing on another GameObject than you think it is
- you're getting an error or warning and you haven't noticed it in the console window

To help gain more insight into your problem, I recommend liberally sprinkling Debug.Log() statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

- is this code even running? which parts are running? how often does it run? what order does it run in?
- what are the values of the variables involved? Are they initialized? Are the values reasonable?
- are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

If you are running a mobile device you can also view the console output. Google for how on your particular mobile target.

Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

Here's an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

https://forum.unity.com/threads/coroutine-missing-hint-and-error.1103197/#post-7100494

Keep in mind you CANNOT mix and match direct Transform manipulation (eg transform.Rotate()) with Physics. Too many cooks in the kitchen.

With Physics (or Physics2D), never manipulate the Transform directly. If you manipulate the Transform directly, you are bypassing the physics system and you can reasonably expect glitching and missed collisions and other physics mayhem.

Always use the .MovePosition() and .MoveRotation() methods on the Rigidbody (or Rigidbody2D) instance in order to move or rotate things. Doing this keeps the physics system informed about what is going on.

https://forum.unity.com/threads/col...-unity-physic-rigidbody.1216875/#post-7763061

https://forum.unity.com/threads/oncollisionenter2d-not-being-called.1266563/#post-8044121

With a wheel collider, use the motor or brake torque to effect motion.

 

Thanks for the reply and tips.

Resolved. The object made-up of two primitives each had their own Rigidbody and I was applying a torque to only one of them. In order for it to move as one whole object I removed the other primitives Rigidbody component where I wasn't applying any torque. Now the whole game object, made-up of two primitives, move together.

Source that help me. https://forum.unity.com/threads/attaching-objects-to-each-other-solved.371660/