Is there a way to influence the material only on a precise part of the mesh?

I wondered if there’s a way to do this :
I have a long plane surface with a material and i want to make it shine at only one part at some moments of my animation (when an object touch it). I would need the part where it shine to be precise, can change and not influence the rest of the mesh. I also can’t do this while separating the mesh since it has some dynamic paint on it that make the whole move. Do you have an idea?

you would have to assign that part of the mesh to a vertex group, then assign that vertex group to a material. Then keyframe the material properties… but, this is a “fixed” approach, meaning, you have to know in advance the place the mesh touch…

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It depends on what exactly you want to do, but you could probably also use a texture or vertex colors for controlling that aspect of the material, using nodes.

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If the plane is UVMapped, you can use a greyscale image texture as the mask for the relevant channel, you could even paint the mask in texture paint to ensure if fell exactly where you wanted.

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actually, the best possible solution actually is using the Dynamic Paint Modifier… Have a look at that…

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Since we don’t really know what your dynamic paint is already doing…I can’t be sure this would help…what ever the object that touches the plane use it to add another Dynamic Brush and create a series of Wet Maps, since you already are familiar with Dynamic Paint this wouldn’t be much of a problem for you…

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Thanks everyone for the usefull tips

The goal was to make the lava “react” when an object is dropped in, by shining more & slightly move while the object sink in.

After few tests Dynamic paint with Wetmaps is perfectly what i needed like RSEhlers & MusicAmg said.
I then use the painted rendered result as a mask as colkai said and it works perfectly :

ty again!