The Projector not show correctly

[sdqq1234]

I used Projector and AoE Target/Alpha Blend shader,when the Carpet shader’s Alpha Cutoff is zero,it looks like ok

but if I set the AlphaCutoff more than zero and cut out the four corners,The Projector not show correctly,the projector appeared in air on the four corners place

How can I solve this problem

Shader "AoE Target/Alpha Blend" {
  Properties {
  	  _Color ("Main Color", Color) = (1,1,1,1)   	
          _Tex ("Texture", 2D) = "" { TexGen ObjectLinear }
  }
  Subshader {
     Pass {    
		ZWrite off
        Fog { Color (0, 0, 0) }
        Color [_Color]
        ColorMask RGB
        Blend OneMinusSrcAlpha SrcAlpha
		Offset -1, -1	
        SetTexture [_Tex] {
		   combine texture * primary, ONE - texture
           Matrix [_Projector]
        }
     }
  }
}

[Dolkar]

I can’t see any difference apart from the cutoff.

[sdqq1234]

the projector appeared in air on the four corners place

[Daniel-Brauer]

The issue is that the projector uses the same mesh as the carpet, but has no information about the alpha values in the carpet shader. One way of passing those values along would be to have the carpet write to the screen alpha channel, and use DstAlpha in your Blend function. Something like Blend DstAlpha One.

[Lulucifer]

All hails for Daniel