Issues and bugs in the current Principia version

RandomMechEngineer

Hi, I wanted to open a discussion about issues in Principia in the hope that they would be fixed at some point in future.

For now I have these two issues in mind that affect the quality of life.

A minor thing that might not have come across for many but I have issues with, is the joint strength on PC vs Android version. When using multi-select to adjust joint strenght, the resulting strength is much weaker when set on PC compared to the same strength values on Android.

Another not so significant bug is the rendering of painted terrain. Sometimes it appears invisible on random spots, both while in editor and playing.

ROllerozxa

Posted by RandomMechEngineer
Hi, I wanted to open a discussion about issues in Principia in the hope that they would be fixed at some point in future.

Usually you should report bugs on the issue tracker, but the forums are okay too.

Posted by RandomMechEngineer
A minor thing that might not have come across for many but I have issues with, is the joint strength on PC vs Android version. When using multi-select to adjust joint strenght, the resulting strength is much weaker when set on PC compared to the same strength values on Android.

Don't really understand what you mean here. The strength value is the same when changing on both Android and desktop. The dialog may be slightly different but it ends up setting the same strength. The physics engine should be the same across all platforms (but realistically will vary because the Android version is built with completely different compiler options for a different architecture, it's a mess nobody really wants to deal with).

Posted by RandomMechEngineer
Another not so significant bug is the rendering of painted terrain. Sometimes it appears invisible on random spots, both while in editor and playing.

Yes I've been aware of this issue for quite some time, it is rather strange. Occurs both when painting in a non-chunked level and with chunked terrain generation. Usually seems to happen when the camera is zoomed out so must be a limit in how many textured pixels it can render.

I've opened #156 for it. Why it just cleanly cuts off like that I don't know. Because this is how it usually looks if you hit the limit of how many regular pixels Principia can render which pretty clearly looks like a vertex limit, creating some funny graphical issues:

RandomMechEngineer

Hi, thanks for the response and for letting me know about the issue tracker.

This is what I meant by the strength setting.

I created a level with two identical setups: three thick planks connected together and supported by platforms at both ends, and a weight dropping on the center. I set the strength to 1.2 on one setup on Android using Multi-Select.
I sent the file to my PC. I set the strength on the other setup to 1.2 as well, using Multi-Select.
When played, the connections modified on PC broke, while those modified on Android only didn't.

For me the problem is that on PC I can't set the connections to be strong enough so I have to do that on Android.

ROllerozxa

Okay I see, so it's an issue with the multiselect connection strength dialog (makes sense, since they are duplicated across platforms and without a doubt contain inconsistencies).

I did some digging in the code and saw that, while the strength that is reported by the desktop dialog is accurate to what the game tells, this is not the case on Android. On Android the strength multiplier factor when converting from a float to an integer is wrong by a single zero causing the strength to effectively be multiplied by 10. This would mean that e.g. 0.05 becomes 0.5 (50%) and 0.1 is indestructible. When you say 1.2 I assume you mean 0.2, which would become 2 on Android (basically indestructible).

So anything above 0.1 on Android, as it is currently, would be indestructible while on PC the only time it is indestructible is 1.0 when the slider is at its max. Dunno what to tell you about having to set strengths on Android. There's no strength level you cannot apply on PC, it's just heavily skewed against indestructible on Android.

Anyways the fix for the Android dialog seems trivial, but it is really late here so I'll save committing it for tomorrow.

RandomMechEngineer

Personally I would prefer the possibility to set a higher strength to the connections, because some of my levels benefit from those higher values settable on Android only. Even though the strength is multiplied by 10, the connection doesn't become indestructible when set above 0.1. Instead, the connection has a high stiffness and breaks under heavy load. This is unless the value is set precisely to 1 with the slider, in which case it becomes truly indestructible and stiff.

In my experiment 'Realistic Offroad Vehicle 2024' which I recently published, I have long beams consisting of planks which the vehicle is driven over. I can make them so strong but still breakable only on Android.

Essentially the best scenario would be to have the same strength values on PC as on Android because it allows the user to choose the strength from a wider range. To my experience the 'wrong' strength multiplier factor on Android is better.