How to Show Metal Heat Effect

Hi all. I have some textured weapon models that have metallic textures. I'd like to have the ends of the barrels get red hot when firing for a period of time. What's a good approach to do this sort of thing in Unity HDRP? Thank you for any tips you can provide.

 

Write shader, which reads from global variable, or per material variable and use grayscale mask on barrel and some color tint property for setting overheat color and just use emission for overheat, lerp normal color to overheat color by variable which you set in global\per-material variable (normalized in [0-1] range) and mul this value to mask. Behaviour same - no matter HDRP or built-in render pipeline. You can do it manually, or use Shader Graph for HDRP.

 

Why so complicated? Just use emission map and animation.