Help with viewport Camera Calculation math(idk what to call this)

[edgy pewter]

I'm working on a system like no man's sky for seamless transition between interplanetary space and going into the planet with no loading screens i mostly got the planet generation down with a chunk system and some perlin noise(the image should kinda look like pluto)

What I'm currently working on is rendering the planet when your in interplanetary space
the way i do this is i have an invisible part follow the player so it doesn't derender when u are far away and attached a billboardgui and then viewportframe and scale the billboard so i can get past the max part limit
but now i have to calculate what the viewport should show if you are looking at it which i do with this code

local cameraDistance = 1
local planet = workspace:WaitForChild("Planet")
local planetPosition = Vector3.new(0,0,-10)


game:GetService("RunService").RenderStepped:Connect(function()
    planet.Position = playerRoot.Position
    
    local playerCam = workspace.CurrentCamera.CFrame
    local dir = (playerCam.Position - planet.Position).Unit
    local camPos = dir * cameraDistance

    vpCam.CFrame = CFrame.lookAt(camPos, Vector3.new(0,0,0))
    
    local offset = planetPosition - playerRoot.Position
    billboardGui.StudsOffsetWorldSpace = offset
end)

it kinda works as you can see in the videos but the bigger the planet is the more you can see wrong
idk why it is like that but I'm tired and have a fever and am being stupid right now

I left a ms paint image i made in like 5 seconds to show should be happening but most likely looks scribbles

if someone could point out why my code is bad or recommend a different way to render planets much thanks would be appreciated

ps: mb if this all sounds like yapping or gibberish

im going to sleep now

when i wake up hopefully a smart person would have figured this out

[idle edge]

i don't have your answer but i just appreciate the actual, rare good quality scripting help post

[left tangle]

So I would advice just using the age old optimization trick: levels of details
e.g. a game, with a nice building, from upclose you can see all the details, then from far away you think that you see the same mesh, but in reality it's a very simplified version of it (as seen with the bunny in pic1).

Then, as for the scale, I do partially like moving the model around to not cause it to not render. You can look at something similar to what the game (steam game) Subliminal does. Scaling based camera position. Basically, you can use the inverse square law to determine how large your object has to be, to appear the same as an object that's a certain size, but closer to the camera.
Now you can use that to fake the distance without it derendering (pic 2 shows the inverse square law, in cause you do not know it yet(technically to calculate light, but vision is light based 😉 ))

[edgy pewter]

I was going to add LOD later on

and i did think about moving the player just small amounts and other things to fake scale but when you fly towards the planets and land on everything would be weird and im pretty sure it wouldnt work

as well as moving the player little amounts to fake scale would still cause the same weird rotating issue with the planets

Thanks for your help tho

[left tangle]

I didn't really mean for you to not move the player as much (even though that could be a good solution to be frank), you could just have them move the normal amount, but just have the planets follow the player at a consistent distance, just decreasing scale

[edgy pewter]

i dont think there is any pros to this system compared to the current one cause it wouldnt solve the rotating issue

[left tangle]

Well there is, LOD wouldn't have to rotate, if you're worried for performance and rendering (which seems like the entire reasons you're doing this), then I don't see why you're doing CFrame calculations

[edgy pewter]

why wouldnt i have to rotate if i was using LOD?

[left tangle]

I don't even see why it is currently rotating, the sole rotation that I can think of is the player's location respective to the current rotation of the planet. Yet if the planet is already a physical entity, then it "rotates" automatically

[edgy pewter]

the main reason its not a physical entity is the max part limit i want to be able to make big planets

[left tangle]

Then we've 2 choices:

lod system, physical entity, but only "1" part (or a low tri count mesh) at the lowest lod. Which has to be premade.
or, a UI system with a premade picture.

Both will be similar in performance (compared to just having the entire planet scaled down), so 🤷‍♂️

[edgy pewter]

like i said i will hit the max part size if i get to close to the planet and i need to be able to land on the planet i will switch to my other terrian generating code when i hit a distance from then planet but before then i will hit the max part limit

so im only left with the other option which im currently using

which has the math wrong

[hasty shadow]

Why dont you just have them as ui elements when extremely far away, and enable planet meshes within a closer distance? As far as I know disabled parts wont count toward the part limit

Ok nevermind they do 🐧

[edgy pewter]

its not the part limit im worried about

part size limit

[hasty shadow]

Ohhhh

[edgy pewter]

and the ui planets dont look good scaled up and far away so i would still need to fix that

[hasty shadow]

Ur cooked then 🙏

[tough bay]

** You are now Level 7! **

[edgy pewter]

ik

gonna go see if ai can fix this

last resort

wait

i think i found the probleem

basically
local dir = (playerCam.Position - planet.Position).Unit
should be
local dir = (playerCam.Position - planetPosition).Unit

i forgot to change it when i started making the planet follow the player for infinite view distance

im really stupid

i am now see some problems with having it be ui

[edgy pewter]

compared to this

theres still some problems with it being ui