Back in the early 2000s, the term draw distance was used a lot more than it is today. Not because it doesn’t exist anymore, but because it was a bigger technical hurdle for game developers. In the early 2000s 3D gaming was breaking out of its infancy and the rendering techniques were starting to become far more proficient. Computer hardware was still a limiting factor which is what caused draw distance to become a source of discussion.
So what does draw distance mean? The term simply means how far into the distance that objects will be rendered. It is also referred to as render distance which might be a more accurate description of what it actually is. Render distance or draw distance is a measurement of how far away from the player in game object will be rendered.
In the real world, the horizon is about 5km away. If there is a boat sailing across the horizon, then you are looking at something that is about 5km away. The real world has no physical limitations as to how far away something can exist. The human eye can only see so far, but an item 1 million kilometers away still exists, even if you can’t see it with the naked eye.
With video games, there is a limited amount of processing power available. An item that is 5km away from the player will require memory and CPU resources to show up on the screen. The game developer will need to decide if rendering something 5km in the distance is worthwhile and if so, is there enough resources to allow for it.
In large open world games, it is common to see a white fog in the distance, which can sometimes be called fog of war but is not the best term to use for it. This is where the draw distance ends. Mountains, trees and objects will fade away into the fog unless you walk toward them. The fog is there to hide the fact that the area beyond this point is not loaded into memory.
Over the years this has become something that we rarely notice anymore. Draw distances are so far now that you can see across the map as well as the human eye could in the real world. You can trees at the other side of the map. There are some clever rendering techniques used to make this happen, but the fact is that with modern gaming, render distance is no longer something people need to discuss.
Why can’t a draw distance be unlimited?
Draw distance can go on for as long as the system hardware can handle. Larger draw distances will negatively impact the games frame rate. If a game doesn’t need to render items far off in the distance, then why bother?
If you are 5 miles away from an enemy. He can’t kill you, you can’t kill him. You are too far away from each other to interact, but you will still want to know the enemy is there. This is worth rendering right? It is, but it doesn’t do much for the player. Put a mountain in the way and you have solved the problem. You can’t interact with the enemy and since the mountain is hiding them, there is absolutely no reason for the enemy to be rendered.
Draw distances are not unlimited because it comes at a performance cost. If a developer is in a position where something far in the distance needs to be rendered, it might be better to consider a change to the level to obstruct the view rather than making other sacrifices to allow for a larger render distance.