What is texel density?
When designers and photographers work on 2D designs or photographs, they try to keep their quality to a high scale so that they appear attractive, sharp, and crisp. The standard of quality in images is determined by the number of pixels present.
However, when we apply texture to objects using any 3D software, the number of pixels does not help a lot. This is because in the 3D world, the number of pixels does not matter; it’s texels that matter. Texel density is the size of the UV island or UV shell; the bigger the size of the UV island or shell, the sharper and crisper the image will look.
UV island, or UV shell
A UV island, also known as a shell, is a connected group of UVs on a UV map. UVs resemble vertices, except they determine how a 2D texture is transferred onto a 3D model’s surface. Your 2D texture is stored in the UV map, together with the layout of your UV islands or shells, which serve as coordinates for where the texture is placed...