Making certain polgyons/ vertices on mesh transparent.

I'm currently producing a mesh in script for procedural generations reasons. For part of the mesh, I want to create water. How would I go about making part of it have lower transparency to simulate the look of it?

 

There is quite a few ways to achieve this depending on what exactly you are trying to do. But I would start with setting the alpha of each vertex then using a custom shader to render it. Although if you are only having a small portion of the mesh transparent, you'd be better off having a separate mesh.

 

I'm not that savvy with shader code. Even more, I wouldn't exactly know how to go about making certain vertices a certain alpha, unless it's like OPenGL and DirectX where you can temporarily change the color to use on following vertices. And I was thinking a separate mesh, but I sort of don't want to go that option unless it's the last. It's for coding reasons.

 

When you're creating the procedural mesh just set the colors property of the mesh, so:

mesh.colors=new Color[]{
etc
};

For the shader you'd want to take the alpha blended surface shader and look at modifying it, but generally you'll get much better performance using two meshes, rendering alpha is much slower, and depending on what you're doing you'll start to hit sorting issues.

 

Yeah because the way I do it, I set up vertices in a list first, then in a separate function that's called during update, the new vertices and uvs are added to the mesh. So there's little way for the other function to know whether the next vertices are water-based or not. I have a matrix to keep track of what vertices are where, but I can only wonder if this will be a headache later on.

 

I think it will, create a class that tracks it all, then have an update function that creates the different meshes needed, it will be a little work before you get that basic results, but long term will be way more flexible.

 

If I understand correctly, you want to apply multiple materials to a mesh.

To apply multiple materials to a mesh, the mesh is divided into several sub-meshes using Mesh.SetTriangles.

After, assign materials in the renderer component in the same order as the sub-meshes.