Problem passing tangent value to shader. Not stable.

Hello,

I am making a shader which need to pass some calculated value to the shader. I am using mesh.tangents to pass the value and the value is set at the Awake() methods. It should not be changed afterward.

Then shader is assigned to a object. The object is animated by script and continue rotating.

But i found that the assigned target value is not stable in the shader, it sometime changed when running.

My input structure is like below.

Code (CSharp):

1.             // Input stucture
2.             struct appdata
3.             {
4.                 float4 tangent : TANGENT;
5.                 float4 vertex : POSITION;
6.                 float3 normal : NORMAL;
7.             };

Any idea why the input tangent value is not stable?

P.S. I also try using uv for passing the value but same.

 

What kind of value are you passing? If it's a object relative position it might be your objects are getting dynamically batched making the position you're passing no longer accurate. Try passing a world space position instead, or disable batching on your shader.
Tags{ "DisableBatching"="True" }

 

I try to calculate a dedicated uv value for the mesh. The value should not be changed.

And i found that the problem only occur for blender imported model. Seem not problem on other model.