Child object shakes the farther away I am from origin?

Unity Engine
1

So this bug doesn’t appear in the editor but it does on iOS, tried an iPhone and iPad, both have the problem.

I have a spot light attached to my sprite, no scripts on the spot light.
Initially, the spot light looks fine, but when I start getting farther from the origin, the spot lights starts shaking around. It gets worse the farther I move. If I return, the spotlight fixes itself.

I was wondering if maybe this was some kind of floating point error and what possibly could be done.
Thanks.

2

Having good world scales like 1 unit = 1 meter helps a whole lot. Floating point will gradually have less decimal precision further from the origin you are. If you use 1 unit = 1 meter, that’s kind of like 15-20 miles before things go bad… which is usually more than enough for a small world area.

Origin shifting is possible but preferable for Unity to handle since all world space particle systems would break, physics would cry and so on… not an easy thing to solve.

3

Interesting. Although I have 1 unit = 1 meter and this becomes very noticeable at around 100 meters away from origin, 1/16th of a mile. I tried going 15 miles far in the editor and a lot of things went funky, including my GUI, but on iOS, only the child attached to my player had issues. Hmm.

Just did a bunch of tests. Appears to be only an issue with lights. Tried messing with its rotation and updating its position manually with no luck so far.

4

100 meters seems way too soon! doesn’t make much sense why that would be. What’s the setup? As it only occurs on iOS have you tried without metal? Looks like it may be a good idea to file a bug!

5

The settings are pretty much the default.
Rendering path Forward
static batching on
dynamic batching on
scripting backend mono 2.x
Graphics API Open gl 2.0, so not using metal
.net 2.0 subset
iOS version 6.0

I’ve tried modifying these and running them with no luck. I’ll mess around with it some more later, need to sleep heh.

6

So apparently it’s the shaders.
Sprites > diffuse seems to be the issue.
I could switch to standard, but standard doesn’t appear to support negative x scale or order layer, hmm.