Vertex shader input is scaled?

I notcied strange behaviour when I made shader which used model space in calculations. If it was no scale on object it was fine, but when I added scale it went wrong. So I started to experiment with it, I have made simple shader which is applied to sphere and changes it's vertices:

v2f o;

float3 n = normalize(v.vertex.xyz);

float3 vv = n * 10.25;

float4 nv = float4(vv,1);

o.pos = mul(glstate.matrix.mvp, nv);

// normally this is: o.pos = mul(glstate.matrix.mvp, v.vertex);

It getting vertex, computing normal (object is sphere, so it is simple normalize) and scales normal by 10.25 (just a number). Then resulting vertex is multiplied by MVP matrix as usual.

What was strange for me: resulting spehere is not affected by scale value set in the editor, but if I replacing my vertex by the original v.vertex it works fine. So for me it looks like unity scales vertices somewhere before vertex shader and MVP matrix doesn't contain scale.

Am I correct or it is some misunderstanding here? Also if it is so, is it any way to change this. Thanks.

Correct. Right now (Unity 2.x) all scaled objects are pre-scaled on the CPU. So the GPU or shaders already ever see the already scaled version. Which means they don't have to normalize the normals, for example.

In upcoming Unity 3.0, we plan to let the GPU handle uniform scale. Non-uniform scaled meshes will still be pre-scaled on the CPU.