help a dumb guy with delta and _physics_process | Brackeys Community | Page 1

hardy mica Sep 7, 2024, 1:19 AM

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so delta is the time passed between 2 frames and physics process updates at a fixed rate, so with the fixed rate of the physics process when do i actually need to multiply stuff by delta i thought i understood it until i actually thought about it

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like let's say i multiply something in physics process by delta vs don't multiply it what would the difference be

lucid copper Sep 7, 2024, 1:31 AM

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ye, use the given delta that's passed into the function

hardy mica Sep 7, 2024, 1:31 AM

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so i do need to use it

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then what's the difference between physics process and process

lucid copper Sep 7, 2024, 1:32 AM

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you said it yourself. Physics runs at a fixed rate

hardy mica Sep 7, 2024, 1:32 AM

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then why do i need delta for it

lucid copper Sep 7, 2024, 1:33 AM

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there was a good godot doc about it all let me see if I can find it

hardy mica Sep 7, 2024, 1:33 AM

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alr

lucid copper Sep 7, 2024, 1:34 AM

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https://docs.godotengine.org/en/stable/tutorials/physics/physics_introduction.html
A lot of it is explained in there

Godot Engine documentation

Physics introduction

In game development, you often need to know when two objects in the game intersect or come into contact. This is known as collision detection. When a collision is detected, you typically want somet...

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that's one thing godot is good at vs unity. Good documentation lol

hardy mica Sep 7, 2024, 1:35 AM

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alr tyvm i'll check it out

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oh i see it's to prevent it slowing down due to lag alr

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and not to prevent it from speeding up if it runs fast

lucid copper Sep 7, 2024, 1:42 AM

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the idea is you're promised that the physics will update a number of times per second (50-60), but that doesn't mean it's completely consistent which is why you still need to use the delta

hardy mica Sep 7, 2024, 1:46 AM

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yea i see\

cloud heart Sep 7, 2024, 10:14 AM

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hardy mica so delta is the time passed between 2 frames and physics process updates at a fi...

You use the delta in the same exact case you would use the delta in the physic process, i will explain for you how it works

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So say you want to move a character in the process function,

If you want to move him to the left by 1 pixel evey frame
If your pc goes to 60 FPS you character moves to the left by 60 pixel in a second
Say your pc goes to 120 FPS your character would move by 120 pixel to the left every second

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So
1pixel * 10 FPS = 10 pixel per second
1pixel * 60 FPS = 60 pixel per second
1pixel * 120 FPS = 120 pixel per second

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Now the delta is:
The time elapsed since the previous frame, aka 1/FPS

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So
1pixel * 10 FPS * 1/10 FPS = 1 pixel per second
1pixel * 60 FPS * 1/60 FPS = 1 pixel per second
1pixel * 120 FPS * 1/120 FPS = 1 pixel per second

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That's how you use it, for things that are dependent of the framerates

hardy mica Sep 7, 2024, 10:24 AM

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yea i know that

cloud heart Sep 7, 2024, 10:24 AM

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Now if it's fixed doesn't mean it's not gonna drop framerate, so you would still need to multiply by delta

hardy mica Sep 7, 2024, 10:24 AM

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i'ma sking about physics process not process

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yea ok i got that now

#help a dumb guy with delta and _physics_process