[learn]shader and materials - Creative Core -Map materials with textures
Texture
Textures are 2D maps
2D maps that wrap around 3D objects
doesn’t have a solid color - (polka-dotted, striped, or speckled), imperfections(like scratches or corrosion)
Most real-world objects don’t have uniform reflectivity and smoothness. That’s where maps come in.
Textures are regular image files in formats (uch as BMP, TIF, PNG, and JPG. )
channels - Black and white images, also known as grayscale images. - shade of gray in each pixel.
| shade of gray in each pixel. | One channel | grayscale images | Black and white images |
| combine to create the colors | three channels | Color images | red, green, and blue (RGB) |
| typically contains transparency data. | four channels (three channels + The alpha channe) |
Some image | red, green, blue, and alpha (RGBA). |
| - | - | - | - |
| create the appearance of physical features (other properties besides color or transparency. smoothness, specularity or metalness, direction each pixel faces, ) |
Each channel of an image file | - | - |
Material
use the textures to create materials.
base map
base map texture (defines the diffuse reflection) ( diffuse or albedo) ( regular RGB or RGBA color image file ) (colors )
( can also include transparency information in the alpha channel of the map. )
Tiled Textures
Tiled Textures - seamless textures : these are designed to be tiled without any seams appearing between tiles.
UV mapped Texture
~ lignment of the texture maps
[ UV mapping ] generates these textures using a process
[ UV coordinates ] modeling applications generate their own sets of 2D coordinates
[ UV ] XY coordinates in regular 2D spaces, ( differentiate them from the coordinate system of the environment (XYZ).)
UV coordinates are relative to the mesh, not the 3D space in your scene.
~ multiple meshes ( submeshes)
each with their own material.
UV mapping allows artists to model the surfaces of their objects without using a lot of mesh data or separate textures to provide detail.
~ metallic
the metallic data is in the R, G, and B channels of the texture file, the shader (URP/Lit) only reads the R channel.
Remember that the Specular workflow uses three color channels, and the Metallic workflow uses only R.
~smoothness
