Billboard and scale

Hey,
Trying to get billboarding and scale work in the vertex shader

this makes the scale and billboard work, but the position is wrong

Code (CSharp):

1.                    
2. float4 wpos = mul (_Object2World, v.vertex);              
3. o.pos       = mul(UNITY_MATRIX_P, mul(UNITY_MATRIX_MV, float4(0,0,0,1)) - float4(wpos.x, wpos.y, wpos.z, 0));

this makes the position and billboard work, but not the scale

Code (CSharp):

1.                    
2. float4 wpos = v.vertex;              
3. o.pos       = mul(UNITY_MATRIX_P, mul(UNITY_MATRIX_MV, float4(0,0,0,1)) - float4(wpos.x, wpos.y, wpos.z, 0));
4.  

 

For anyone else who is searching for this answer, it was answered on this stackoverflow question:

https://stackoverflow.com/a/54187589/2926815

Code (csharp):

1.  
2.                 float4 BillboardVertex = mul(UNITY_MATRIX_P,
3.                     mul(UNITY_MATRIX_MV, float4(0.0, 0.0, 0.0, 1.0))
4.                     + float4(v.vertex.x, v.vertex.y, 0.0, 0.0)
5.                     * float4(
6.                         length(unity_ObjectToWorld._m00_m10_m20),
7.                         length(unity_ObjectToWorld._m01_m11_m21), 1.0, 1.0));
8.  

At last this worked for me.