How does KSP have entire planets without lag?

[AdenoidHynkel]

How is KSP able to have several, entire planets without performance issues?

Kerbal has roughly the same surface area as the continent of Africa. That's far from an entire earth-sized planet, but still completely huge. And Kerbal isn't the only planet, there's six more, plus all the moons and asteroids. 

How is KSP able to run so smoothly with so many and so large 3D assets?

[Aerodynamic Kerbal]

1. There's basically nothing in the empty space. Just a full star, galaxies, etc texture sphere around you. And Kerbol. 

2. From far away (orbit), planets are only textures. And an atmosphere. 

3. The game only loads objects around you (like Minecraft's chunk system). You can even see that, including in some mods (Parallax).

I'm not 100% sure if that's how it works, but that's just what I think

Edited July 15, 2023 by Aerodynamic Kerbal

[AdenoidHynkel]

15 hours ago, Aerodynamic Kerbal said:

1. There's basically nothing in the empty space. Just a full sphere around you. And Kerbol. 

2. From far away (orbit), planets are only textures. And an atmosphere. 

3. The game only loads objects around you (like Minecraft's chunk system). You can even see that, including in some mods (Parallax).

I'm not 100% sure if that's how it works, but that's just what I think

Thanks!

[KerikBalm]

Let's not forget that size and detail aren't the same thing.

In 1999, Arma:CWC (then called Operation Flashpoint/OFP) had maps 12.8x12.8 km, with almost 60 km^2 of land

17 years later, Arma 3's expansion came with a map.... 15.36x15.36 km, and about 100km^2 of land.

A modest increase in map size?

The maps went from a 256x256 grid with a 50x50m cell size, to a 4096x4096 grid with a 3.75x3.75m cell size.

The difference in the number of objects was astounding too.

You should also look at detail, and resolution.

A 1000x1000km featureless plain is not really "bigger", computationally speaking, than a 4x4km jungle map just packed with objects, and with a 1m terrain resolution

Ksp planets, for the most part(including mods), are rendered from 1024x2048 (or 2048x4096) height map and texture, or simply from procedural generation, and have simple procedurally generated ground scatter.

It actually not that impressive. It's the physics system that is impressive for KSP

[RevanX_LSR]

On 7/16/2023 at 3:57 AM, KerikBalm said:

Let's not forget that size and detail aren't the same thing.

In 1999, Arma:CWC (then called Operation Flashpoint/OFP) had maps 12.8x12.8 km, with almost 60 km^2 of land

17 years later, Arma 3's expansion came with a map.... 15.36x15.36 km, and about 100km^2 of land.

A modest increase in map size?

The maps went from a 256x256 grid with a 50x50m cell size, to a 4096x4096 grid with a 3.75x3.75m cell size.

The difference in the number of objects was astounding too.

You should also look at detail, and resolution.

A 1000x1000km featureless plain is not really "bigger", computationally speaking, than a 4x4km jungle map just packed with objects, and with a 1m terrain resolution

Ksp planets, for the most part(including mods), are rendered from 1024x2048 (or 2048x4096) height map and texture, or simply from procedural generation, and have simple procedurally generated ground scatter.

It actually not that impressive. It's the physics system that is impressive for KSP

Texture size does not have a notable effect on the lagginess of a game. I have played on both 8192x4096 (e.g. JNSQ) and 4096x2048 mods (GPP) and they both seem to not be laggier than stock planet packs. Probably to do with mipmaps or something

Mipmaps or PQS terrain detail is basically the tendency to reduce quality the further a feature is from you. Minecraft does not use that which is why it is so laggy