Why Do Certain Game Values Change - When Cooked Down To Mobile?

Precision, its all about precision…

After cooking float values becomes half, smooth curves turns into broken lines and so on…

And I think devices itself produces some cuts.

After doing several mobile cook downs recently, I’ve noticed that certain values do not transfer over consistently to the phone.

For example, the characters jump height is slightly less… doors open/close much faster than they should (even using delta time on interps) It seems some values are exaggerated while others are weakened.

This project runs brilliantly during editor testing… but I can’t seem to get the same consistency during the phone conversion (cook down). Any help or ideas as to why this might happen would be greatly appreciated. Thanks

Hello Vicecore,

Your values shouldn’t be changing drastically when cooking for mobile, so could you give me an example that can be reproduced in a fresh project? I’d like to look into this.

As for redbox’s comment, while float precision errors do exist, it’s something that would rarely be noticeable and absolutely would not cause a value to be halved.

Thanks Matthew… for your timely response & interest in resolving this. If you give me some time, I can try and recreate these problems in a new project.

However, I’d be more than happy to send you this project. Again, it runs fantastic in the editor. But if you can cook it down to your/a phone - and run it …you would clearly see what I’m attempting to explain.

If that works for you, just let me know the best way to get it to you and I’ll send it. I’m working today but my partner is off watching this post. He can send it via google drive when you respond back.

Thanks again!

Thanks Redbox …I think both of you guys are correct in a sense. Seems like some values are in fact halved or doubled. Others are barely noticeable.

So when you say “precision” - what you mean is to change values to what you think they should be on a phone …and then keep cooking down until you get the desired result?

It depends.
Some cases you can fix by tweaking values (for example jump velocity).
Another - by changing implementation. For example, by replacing lit materials with unlit but with faked lightning.
And there is something you should ignore, because it requires many time to fix or it is not really noticeable and your project can live with it.

You can send the project by sending a link to me through a private message on our forums.

Anything that you can send a download link from would be fine, such as Google Drive.

Thanks Matthew, sorry for the delay… I’m available this afternoon/ this evening. No problem, I’ll send you a private message.

Is there another way other than DropBox? because if not I would have to update my account.

Ok - So I got the project on my google drive. The thing is I would need an email address so that I can “Share it” Tried sending a private message, but it’s says that requires permission.

You can email me at c*#@c@gmail.com. Then when I get your email, I can then share it

Working on that now …may take up to an hour (for some reason)

Hopefully have this to you very soon

You shouldn’t need any permission to send a private message through our forums. Please use the following link to bring up the form to send a message. If you’re still getting some sort of permission error, please take a screenshot of the message it’s giving you.

https://forums.unrealengine.com/private.php?do=newpm&u=36033

Yea man, not sure why I’m getting that error. I know I’ve used private messaging before. Sorry for any inconvenience

As it mentions, maybe your forum account hasn’t been activated yet. I’m going to leave a private comment that only you and the moderators can see. If you reply to the private comment, your reply will be private as well.

Hey Matthew, I just verified my Epic account - hopefully private messaging should be fine now.

Now you had asked for a link I can share with you.

Hopefully this works - any problems please let me know

Thank you for providing the project. I’m packaging it now to see if I get the same results.

Unrelated to the issue itself, I noticed the size of the project and of some of the assets themselves. I just wanted to point out that many of the assets included are fairly high poly for an Android/iOS project. It would be a good to use lower poly assets if you can, moving forward. A good example is the milkBox and FireExtinguisher.

I packaged the project out (limiting the packaging to just the SideScrollerExampleMap, as the OBB file for the package was way too large otherwise) and didn’t see any odd behavior. Since you mention the values in question are related to interps using delta time, could it be related to framerate issues? You can try simulating a low framerate on your PC by using the t.MaxFPS # console command to set a maximum framerate.

Thanks again Matthew, we’re going to take a day or so to look over all the info you shared with us - and we’re going to do some more cook downs.

Hopefully, the info you provided will help clear up our existing issues. Either way I’ll be in touch to inform you of the outcome.

We haven’t heard from you in a while, vicecore. Are you still experiencing this issue? If so, what were the results of testing what I mentioned? In the meantime, I’ll be marking this issue as resolved for tracking purposes.