Video tutorial link:
There is a model of such a sword
We wanted the blade to be metal, the butt to be stone, and the hilt to be wooden.
I didn’t quite understand it when I first started. A model is divided into 3 materials. When importing it into Unity, you need to create 3 new material balls, which is very cumbersome.
In fact, a model only needs one material. The tutorial is as follows:
1. First, make the blade material and drag an iron material onto the model.
2. Then right-click on the material-Add black mask
3. Then click on the geometry fill in the left column - select the square geometry fill, and set the color selection value on the right to 1
Triangle filling: slow, high accuracy
Geometry filling: fast, medium accuracy
Model filling: very fast, directly select isolated model parts (isolated parts of points, lines and surfaces that are not in contact with other parts)
UV fill: not very clear
4. Then click this drop-down box and change from "Material" to "Mask" view
5. Return to the model view, hold down the left button and pull out the selection box, select the blade area, the selected area is white (remember to check the back side to ensure that all the desired sides are selected)
6. Click the drop-down box in the upper right corner again and change from "Mask" back to "Material" view. The effect has been achieved.
7. By analogy, drag in the material - right-click to add a black mask - fill the selected area with the geometry in the mask view - complete
8. Then export the texture
If more faces are selected when filling the geometry, you can adjust the color selection value to 0 (or directly click the invert value button on the right), then click to select the unnecessary faces, and then these faces can be removed from the mask ( Unnecessary faces are shown in black)