Gravity pulls me up?

[W00f_321]

I have been trying to make a flappy bird clone to learn the basics of unity. But when I did rigid body 2d and set the gravity to 1 it pulled me up. Any ideas for why this could be happening?

[Kurt-Dekker]

Perhaps you have your physics gravity inverted! Check docs for how to change gravity in 2D.

Otherwise, time to start debugging! Here is how you can begin your exciting new debugging adventures:

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

Once you understand what the problem is, you may begin to reason about a solution to the problem.

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 names of the GameObjects or Components involved?
• 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.

You can also supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as Debug.Log("Problem!",this);

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.

Visit Google for how to see console output from builds. If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer or iOS: How To - Capturing Device Logs on iOS or this answer for Android: How To - Capturing Device Logs on Android

If you are working in VR, it might be useful to make your on onscreen log output, or integrate one from the asset store, so you can see what is happening as you operate your software.

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:

Coroutine missing hint and error

This is so unnecessary. Use the beauty and power of instantly and immediately putting a Debug.Log() statement into the very start of the coroutine, right at the top. Do this always at the very first sign of trouble or question in your mind. The instant you did this you would see “Oh man, this code is simply not getting run!” And you could LASER-FOCUS 100% your efforts on studying what you expect to run it, eg., the call location, and isolate why it is not running. You would look at literall…

“When in doubt, print it out!™” - Kurt Dekker (and many others)

Note: the print() function is an alias for Debug.Log() provided by the MonoBehaviour class.

[W00f_321]

Thank you! Just so you know in response to I might have gravity inverted I have tried -1 gravity I don’t know if that would have helped it, but it gave the same result. I will check the other things you said to check.

[Kurt-Dekker]

Don’t waste a lot of time on it. Make a blank scene, put a SpriteRenderer GameObject with a Rigidbody2D in it and press play. Where does it go?

Get the information fast fast fast. If it falls down in the new scene, doesn’t go fall in the main scene, you know it’s something else than the gravity setting.

Start looking at scripts, rebuild the player scene and prefab, this stuff is simple simple stuff, you don’t want to let it bog you down!!

[W00f_321]

I don’t know why something didn’t save properly and the rigid body 2d was gone when I reapplied it it worked. Thank you for the help!

[Alfame]

@W00f_321

I have been trying to make a flappy bird clone to learn the basics of unity. But when I did rigid body 2d and set the gravity to 1 it pulled me up. Any ideas for why this could be happening?

Hi! You probably did the same thing I did: Set the rigidbody2D on the main camera instead of the bird. So from the camera’s POV, the bird flew upwards.
I also feel dumb don’t worry…

[Killiander]

@W00f_321

I have been trying to make a flappy bird clone to learn the basics of unity. But when I did rigid body 2d and set the gravity to 1 it pulled me up. Any ideas for why this could be happening?

This happened to me too and I figured out that I was adding components to the camera by accident, instead of adding them to the game object.