How does scale affect a game's performance?

Hey guys,

I’m relatively new to Unreal Engine 4 and 3D game design in general, and I was wondering about scale. I’m planning a game with a wide angle camera and a large, low detail world (think strategy/simulation games like the Civilization series, Anno series). There is going to be a single player character in the center of the screen, but think of it as a representation, not an actual detailed model. Likewise, objects to interact with and landscapes are going to be iconic, not realistically scaled 3D models.

Now, what do I have to keep in mind in terms of scale and performance?

Taking the Top Down or the Third Person template project as an example - should I just zoom the camera out really far and still keep the player pawn and other objects at the Unreal scale of 1m = 1unit? Or should I scale things down, so that 1 Unreal unit is maybe 100 meters in my game? How does this influence landscape tool settings like the size? And is there a way to view/set the scale for everything in a convenient way?

I realize those are a lot of abstract questions, but maybe someone can shed some light on one aspect or the other? :slight_smile:

Best regards!

Generally speaking what it comes down is the number of draw calls, and the complexity of the objects being drawn. If the camera is really far out, but you haven’t created low detail versions of those objects, you could potentially be drawing a tons of expensive objects.

Scale doesn’t really have an impact on performance, if the end result is the same. Like if i scale everything down, vs zoom the camera out. If the object is same size on screen in either case, they’ll be the same performance. Assuming of course you’ve also calibrated the LOD settings for the meshes to understand the new coordinate system.

Personally, I would just zoom the camera out. Because most strategy games let me zoom the camera anyway, so you’ll probably want to have that functionality anyway.

Cheers,
Nick

Hey Nick, Thanks for your reply!

From what you say, I gather that scale just doesn’t matter for performance - performance depends on what is drawn on the screen. So what I need to keep in mind is the poly count on the screen, and not so much what the scale sliders say in the Unreal Editor. Is that about correct?

Best regards!

Right - Polycount, Material shader complexity, draw fill…etc. There are so many things that can affect performance, but you can safely ignore scale.

Cheers,
Nick