The other day, a friend of mine was going through the list of game options that adjusted various graphic-related settings, but didn’t understand what all of them actually meant. Some of them should be pretty self-explanatory (texture quality - low, medium, high, ultra, for example) but there’s also several other terms that are used that many people have a vague idea about, but aren’t quite sure. Today, I’ll try to explain what they are and how they work.
Bloom is a shader effect that allows lighting to create a sort of feathered halo-ish effect around hard edges. It’s what makes light sort of bleed out over and around corners on things, or when it is reflected on shiny surfaces.
VSync, or Vertical Sync
VSync forces your graphics card to synchronize its display at the same refresh rate as your monitor. This is supposed to guard against screen tearing - when your GPU is caught in between rendering two different frames. It doesn’t always work, though. Turning on VSync will also force your GPU to output at a lower rate, which results in worse overall performance.
Depth of Field
Depth of Field is when the programmers use various shaders to simulate focusing on a specific distance, making things further or closer appear blurry instead of uniformly focused. It’s a shader effect that gets run on top of what you should be seeing if everything were in perfect focus.
When the camera moves faster than the eye can focus, the image gets interpolated with what has just passed to simulate speed. This makes things at lower frame rates feel better, though it will cost graphical computing power since it has to retain what it has just seen for the past few frames and use that data to interpolate what it is you see.
Anti Aliasing takes what you should see and smooths each pixel with the surrounding pixels. This helps keep edges from looking too jagged or pixelated. As a post-processing effect, it also soaks up graphical processing power.
Similar to Anti-Aliasing, it’s used to make textures appear less pixely. As such, you can turn down the texture quality/size without making the textured objects look too blocky if upscaled. It does this by interpolating the pixels on a texture with nearby pixels. The important thing to note here is that texture filtering occurs on the texture itself, while anti-aliasing occurs on what you see on screen.
FOV (Field of View)
Field of View is the width of the camera’s view angle. The wider the angle, the more you can see overall. Extreme width will, however, cause distortions in the proportionality of things.
God Rays are when you have concentrated, visible light beams break through cloud cover or around/in specific areas.
When deciding how to draw a given pixel, the GPU will sample the depth/distance from nearby pixels to figure out how much shadow/depth the nearby pixels should affect the given pixel. This makes crevices and nooks darker than the surroundings.
And that’s it for this blog in 2014. I will be on break and traveling for the next two weeks or so, so updates will be sporadic at best until the new year begins.