Question by 15901519969 · Oct 04, 2016 at 05:14 AM · shader shader programming shaderlab

What is the difference between Semantic POSITION and SV_POSITION both

All I hava a vertex and fragment shader:

 struct a2v
 {
     float4 vertex : POSITION;
     float3 normal : NORMAL;
     float4 texcoord : TEXCOORD0;
 };
 
 struct v2f
 {
     float4 sv_pos : SV_POSITION;
     fixed3 color : COLOR0;
 };
 
 /*Unity Report Error over here!!*/
 v2f vert(a2v v) : **SV_POSITION**
 {
     v2f o;
     o.sv_pos = mul(UNITY_MATRIX_MVP, v.vertex);
     o.color = v.normal * 0.5 + fixed3(0.5, 0.5, 0.5);
     return o;
 }
 
 fixed4 frag(v2f i) : SV_Target
 {
     fixed3 c = i.color;
     c *= _Color.rgb;
     return fixed4(c, 1.0);
 }

if I Complie with DX11 Unity will report the error: Shader error in 'Custom/Shader2': invalid output semantic 'SV_POSITION': Legal indices are in [0,0] at line 41 (on d3d11)

and the shader doesn't work well!

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