Vertex Movement

Hey guys,

New to working with shaders, and I've run into a bit of an issue. I've successfully managed to move the vertices in a mesh along a sin wave, but now I'd like to restrict which vertices move based on an image.



I'm using the above gradient to try and only move the vertices at the top of the mesh, while leaving the ones at the bottom in place.

I'm trying to do a lookup of the image and use the associated value to influence how much the vertex moves, but it's not working as expected. Both the top and bottom of the mesh is moving, and the center seems to stay relatively in the same space.

Code (csharp):

1.  
2. void vert (inout appdata_full v, out Input o) {
3.        
4.             UNITY_INITIALIZE_OUTPUT(Input,o);
5.  
6.             float4 tex = tex2Dlod(_MeshDeformationMask, float4(v.texcoord.xy, 0, 0));
7.             v.vertex.x += sin((v.vertex.y + _Time * _MeshDeform1) * _MeshDeform2 ) * _MeshDeform3 * tex.y;
8.         }
9.  

I'm struggling to figure out which variables are available to me to work with, and I've only gotten this far after looking at examples online. Any help or suggestions people can offer would be really appreciated.

Thanks!

 

There's nothing obvious from the code, though I don't know what your model / UVs look like. If you use that texture as your main texture map and show it as the albedo does it show as you would expect?

You could also just use the model's normals to determine "up" in either world or model space, or use a UV channel / vertex color to store values instead of using UVs and a texture depending on your goal. Something as simple as that gradient could be replicated with saturate(v.texcoord.y * 2.0 - 1.0);

 

bgolus, first you helped me with a tip on making KinoFog work, and now you're here to the rescue again. You're my new favorite person.

Using vertex colors wasn't an option, but using saturate(v.texcoord.y * 2.0 - 1.0) was just what I needed.

Now I just need to figure out what I need to do to get shadows matching up with my moving vertices.

 

#pragma surface surf ...stuff... addshadow

https://docs.unity3d.com/Manual/SL-SurfaceShaders.html

 

Thanks bgolus, that did the trick! For anyone interested,
#pragma surface surf StandardSpecular vertex:vert addshadow
is the full line that did the trick for me.