Vertex Color (Vertex Color) is a technical term that is extremely important in rendering and optimizing game graphics (technical art). RGB (and Alpha) color information stored in each "vertex" of a 3D model itself, and is used as a coloring or mask in a shader without using a texture.
An example in the real world: When swinging a wire rope, the hardness of the "fixed part at hand (black)" and the "swinging tip (white)" are painted differently
Vertex color is a ``doodle memo written directly with a marker on each joint or part of a 3D model, such as ``This part should move like this (white)'' and ``This part should never move (black).'' There is no need to load image files (textures), so memory consumption is completely zero. By simply reading the characters (numbers) in this memo, the shader can control the range of motion of each part of the model and the disappearance gradation of each particle at lightning speed.
Figure: An infographic that clearly illustrates the basic processing flow and mechanism of Vertex Color (vertex color) in Japanese notation
Detailed mechanism and operating principle
Use the DCC tool to paint the vertex color on the root side of the model as black (0.0) and the tip side as white (1.0), and in the vertex shader, select "Vertex displacement × vertex color.r" to control the width of fluctuation.