How to make textures?

Anyone knows how to make the textures, like displacement, reflection, diffuse, bump and normal pass, or any tutorials that can be referenced?

Adobe has now ‘Substance Sampler’ which is basically a dedicated tool to create textures/materials from images. There are also quite a lot online pages where you can convert your texture to the right maps.

One interesting one I just noticed is this: Generate 3D Textures for Free | Polycam
It uses AI to generate unique textures which you can download and contains roughness/albedo/normals/displacement. Not the biggest resolution but interesting concept.

One which can create the maps from a picture you can find here but there are a lot of these: Online AI PBR Material Generator - Digimans.ai

Just be sure the image you submit is an image without shadows, other tools can remove them but you don’t want shadows since they will give a wrong result if the light hits at another angle.