Blurry Skybox Texture

Question

I have a problem when I render my skybox. I am using DirectX 11 with c++. The picture is too blurry. I think it might me I'm using too low resolution textures. Currently for every face of the skybox, the resolution is 1024x1024. My screen resolution is 1920x1080. On average I will be staring into one face of the skybox at all times, this means the 1024x1024 picture will be stretched to fill my screen, which is why it is blurry. I'm considering using 2048x2048 textures. I created a simple skybox texture and it is not blurry anymore. But my problem is it takes too much memory! Almost 100MB loaded to the GPU just for the background.

My question is that is there a better way to render skyboxes? I've looked around on the internet without much luck. Some say that the norm is 512x512 per face. The blurriness then is unacceptable. I'm wondering how the commercial games did their skyboxes? Did they use huge texture sizes? In particular, for those have seen it, I love the Dead Space 3 space environment. I would like to create something like that. So how did they do it?

Answer 1

Firstly, the pixel density will depend not only on the resolution of your texture and the screen, but also the field of view. A narrow field of view will result in less of the skybox filling the screen, and thus will zoom into the texture more, requiring higher resolution. You don't say exactly what FOV you're using, but I'm a little surprised a 1k texture is particularly blurry, so maybe it's a bit on the narrow side?

Oh, and before I forget - you should be using compressed textures... 2k textures shouldn't be that scary.

However, aside from changing the resolution, which obviously does start to burn through memory fairly quickly, I generally always combine the skybox with some simple distant objects.

For example, in a space scene I would probably render a fairly simple skybox which only contained things like nebula, etc., where resolution wasn't critical. I'd perhaps render at least some of the stars as sprites, where the texture density can be locally higher. A planet could be textured geometry.

If I was rendering a more traditional outdoor scene, I could render sky and clouds on the skybox, but a distant horizon as geometry. A moon in the sky might be an overlay.

There is no one standard answer - a variety of techniques can be employed, depending on the situation.