mainCamera.WorldToScreenPoint inaccurate

[LaCrak27]

So, as the title says, i think that the function is innacurate. Im using it to position boxes on the targets of my spaceship game, and when i move and rotate the ship, the box drifts from its target a lot, and i dont know how to fix it. Is there any way i can make it be on target?

[Kurt-Dekker]

The function will be perfectly accurate.

You may be giving it incorrect information (wrong location, wrong camera?)

You may also be mis-using the output or your screen object is offset from its center

Photographs of code are not a thing. If you post a code snippet, ALWAYS USE CODE TAGS:

How to use code tags: Using code tags properly

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 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.

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!™

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

[PraetorBlue]

@LaCrak27

i think that the function is innacurate

Actually your problem is assuming that Canvas space and Screen space are the same thing. This is not true. Canvas space is a whole separate and mysterious beast.

[LaCrak27]

@Kurt-Dekker

The function will be perfectly accurate.

You may be giving it incorrect information (wrong location, wrong camera?)

You may also be mis-using the output or your screen object is offset from its center

Photographs of code are not a thing. If you post a code snippet, ALWAYS USE CODE TAGS:

How to use code tags: https://discussions.unity.com/t/481379

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 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.

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: https://discussions.unity.com/t/700551 or this answer for Android: https://discussions.unity.com/t/699654

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:

https://discussions.unity.com/t/839300/3

When in doubt, print it out!™

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

Thanks for the detailed response, i will try to follow said debugging steps

[LaCrak27]

@PraetorBlue

Actually your problem is assuming that Canvas space and Screen space are the same thing. This is not true. Canvas space is a whole separate and mysterious beast.

thats probably it, i’ll do some research and see what i can find

[LaCrak27]

@Kurt-Dekker

The function will be perfectly accurate.

You may be giving it incorrect information (wrong location, wrong camera?)

You may also be mis-using the output or your screen object is offset from its center

Photographs of code are not a thing. If you post a code snippet, ALWAYS USE CODE TAGS:

How to use code tags: https://discussions.unity.com/t/481379

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 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.

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: https://discussions.unity.com/t/700551 or this answer for Android: https://discussions.unity.com/t/699654

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:

https://discussions.unity.com/t/839300/3

When in doubt, print it out!™

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

I have tried doing all that, and none of it worked. I think that a video of the problem might help, which i attached here(
https://www.youtube.com/watch?v=1fWV9pAX9Yk
). As you can see, the problem doesnt even appear at 1st, and only does so as time goes by. It also cant be a result of floating point calculations cuz if i manually move both ships to the center after the error occurs, it is still there. How can i fix this?

[PraetorBlue]

@LaCrak27

I have tried doing all that, and none of it worked.

When and where are you running the code that positions the square? Have you tried putting it in LateUpdate?

[Kurt-Dekker]

@LaCrak27

As you can see, the problem doesnt even appear at 1st, and only does so as time goes by

Looks like perhaps you’re traveling very far away from (0,0,0). Is that what you’re doing?

If so you need to either:

• not travel so far away (1000 to 2000 units is best, 10,000 units away is an upper outer limit)

OR

• implement a floating origin system.

This is due to single precision floating point inaccuracy, which means you need to stay within “reasonable” numbers in order to have “reasonable” accuracy in those numbers.

[LaCrak27]

@Kurt-Dekker

Looks like perhaps you’re traveling very far away from (0,0,0). Is that what you’re doing?

If so you need to either:

• not travel so far away (1000 to 2000 units is best, 10,000 units away is an upper outer limit)

OR

• implement a floating origin system.

This is due to single precision floating point inaccuracy, which means you need to stay within “reasonable” numbers in order to have “reasonable” accuracy in those numbers.

as i said, that cant be it, since when i move them ships manually to 0,0,0 the bug is still there

[LaCrak27]

@PraetorBlue

When and where are you running the code that positions the square? Have you tried putting it in LateUpdate?

i’ve tried fixed update, although lemme give latupdate a try

[LaCrak27]

nope, same issue

[LaCrak27]

also, if it was floating point inaccuraccy, woudnt everything be affected?