As shown in the picture, there are two VRaySwitchMtl materials.
Switch Material 1 is the base paint of the vehicle, and Switch Material 2 is the two-tone paint.
What I want to know is how to make Switch Material 2 change its number along with Switch Material 1 when I change the switch value of Material 1 from 0 to 9.
Would you be able to provide a related tutorial or any guidance on this?
You can use a Bezier Float to control both values simultaneously. To do that, in the Slate Material Editor, right-click the VRaySwitchMtl and activate “Show Additional Parameters”, then plug the Bezier Float to the switch_number of both. This way, changing the value of the Bezier Float changes that Switch Value for both materials.
Another option would be the material ID modifer on these objects along with a corresponding Multisub material. That way you can animate the ID of the material modifier, and the multisub will make the switch to another material.