/vr/ - Retro Games

>>6068585
>>6068590
>>6068601
>>6068614
When you always use full scale textures, distant texture texels fight for screenspace resulting in randomly selected texel being displayed.
This results in shimmering in the distance, and major distortions when texture is vewed at an angle.

Mipmapping rescales texture by factor of 2/4/8 etc. until it hits defined minimum. This reduces distortion in the distance, and in case with relatively low texture count can improve performance at the cost of slight VRAM requirement increase.

Anisotropy is a secondary mipmapping technique that does additional horizontal and vertical scaling for when texture is displayed at a high angle.

Texture nearest, mipmap linear is the best solution. Nearest mipmap bungles up some of the details at medium-far range since it just removes some pixels. Linear interpolation blends adjuscent pixels, but you won't notice it at the distance it is performed if it is coupled with high anisotropy due to way it works.

Long story short, in this case linear mipmap actually preserves more detail than nearest or bilinear/trilinear.

Also there's never a reason NOT to use 16x anisotropy instead of 8x since VRAM hit is neglegible with Doom's low texture count.

>>5875120
(cont)
Linear->Bilinear->trilinear filters use increasing amount of samples. Less samples preserves more details for low-res content, where details can be as small as a a group of a few pixels, while more samples results in better image for highres textures.
Filters generate mipmaps as a side effect on their own, but they are incredibly shitty and blurry, since the amount of mips is low.
Separate mipmap pass is always preferred.
Nearest mipmap filter is shit as it essentially represents a detail on the texuture with a random pixel form that detail regardless of how it will look.
Linear mipmap represent the detail on a texture by merging the colors of surrounding piels that were omitted, but does not do any additional blurring thus preserving most of the detail.
Bilinear mipmaps and filter are shit all around the board.
Trilinear mipmaps use more samples, and result in better quality on high-res textures, but a bit blurrier than linear on low-res textures.

The galery linked above shows comparison of the full screenshots, but here's a cropped variant. As you can see Linear mipmaps + x16 anisotropy produces the best results. with sharper textures in the middle range and benefits of anisotropy resulting in no shimmer and preservation of distant detail, while trilinear starts to blur things too much at the mid-range.