variable 'o' used without having been completely initial (d3d9) 68

my many shader (download from net) find a error like this:

variable 'o' used without having been completely initial (d3d9) 68

and in shader like this:

Code (CSharp):

1.  
2. v2f vert (appdata_img v)
3.             {
4.                 v2f o;
5.                 o.vertex = mul(UNITY_MATRIX_MVP, v.vertex);
6.                 #ifdef SOFTPARTICLES_ON
7.                 o.projPos = ComputeScreenPos (o.vertex);
8.                 COMPUTE_EYEDEPTH(o.projPos.z);
9.                 #endif
10.                 o.texcoord = TRANSFORM_TEX(v.texcoord.xy, _MainTex);
11.                 return o;
12.             }
13.  

i think may be my 5.3 make this error.
please tell me how to init this 'o' completely!

thanks very much.

 

That error indicates that your method is failing to write a value to each field of your v2f struct when compiling the shader for d3d9. You need to make sure that each field of 'o' has a value before your return it.

 

Unity actually has a shortcut that will do this for you. If you look in some of the includes for the standard shader you will find:

Code (csharp):

1.  
2. VertexOutputForwardBase o;
3. UNITY_INITIALIZE_OUTPUT(VertexOutputForwardBase, o);
4.  

That should initialize everything to 0; I believe it resolves to "name = (type)0" on platforms that need it. You should be able to use that as well (i.e. "UNITY_INITIALIZE_OUTPUT(v2f, o);") anywhere you are getting this error.