Texture rotation resets after full rotation

ricardo22448 · January 2, 2025, 9:33pm

Hi all,

I have a day and night cycle but when the moon reaches 24(midnight) then it suddenly resets the rotation to the 0 position. how can i change this so that the moon rotates to the 0 position?

24( this is the 0 state)
23(this is just before full rotation

hope someone can help! thank you!

ricardo22448 · January 3, 2025, 8:51pm

Someone know why this happens? it rotates the z from 0 to 180 is there a way to lock this? it is the directional light

fliprly · January 3, 2025, 9:21pm

Which direction your are spinning?

fhaab · January 3, 2025, 9:27pm

I think it’s your time of day comparison.

If time of day crosses midnight, it’s resetting to 00:00:00, which is before Dusk.

The comparison should be (TimeOfDay > Dusk) OR (TimeOfDay < Dawn)?

ricardo22448 · January 3, 2025, 11:22pm

hi!

i made it somewhat easier to put the moon cycle on a 24 to 48 hour , the sun goes from 0 to -180 and the moon goes to -180 to 0

so what i see is that after hour 37 the moon directional light suddenly flips from 0 to 180

up image is time of day 35

down image is 37 and rotation z is suddenly 180

the same thing happens with the sun at the highest point it suddenly flips on the rotational z 180 degrees. but you just cannot see it because it has no texture

ricardo22448 · January 3, 2025, 11:24pm

plz see comment above

fhaab · January 4, 2025, 5:32pm

So I’m not going to wire all this up and test it, but I certainly have had problems with rotations and Unreal making the equivalence that -180 = 180, that -10 = 350, etc.

So can you try adjusting your ranges, instead of 0 to -180, and -180 to 0, doing 360 to 180, and 180 to 360?

ricardo22448 · January 4, 2025, 5:46pm

Thank you for your answer, i will try this and get back to you!

ricardo22448 · January 4, 2025, 6:29pm

Hey i tried it but it is the same at the half point the directional light suddenly turn to negative.

i made a new blueprint with only sky atmosphere and a directional light an on the light with the property Forward Shading Priority on one, i changed nothing else.

then i just made a float with the range of 0 to 24 and the following components that fire from the constructor script :

when i put the blueprint in my scene and go to the 0 time:

then i see the directional light on 180 on the z rotation axis

then when i go to a half point like day of time 12:

the directional light suddenly goes to - 180 on the z axis :

very weird that this happens

fhaab · January 4, 2025, 6:41pm

I’m not sure what the problem is, but I still think one problem is your range of 0-24 mapping (now) to 180 to 360; if your value rolls over from 24 back to 0 at midnight, the rotation will snap back to 180.

The other thing is I feel like you shouldn’t be “adding” instead of “setting” the world rotation.