Projector and Shader with modified Vertices

Hi!

I've come across a problem while working in a scene that has a Projector that covers most of the scene. My goal was to add grass that I would bend in the wind, and I would modify the vertices in the Shader directly. To my surprise I found that the Projector would affect the original position of the vertices and not the new position.

(In the image, I have a simple reproduction of the problem, with vertices modified by float3(0, 1, 0) + mul (unity_ObjectToWorld, v.vertex).xyz, just to show the effect)

So I was hoping I would be able to keep the projector and the bended grass but I have no idea how that would be done. It seems like a Unity Bug to me, but I wanted to make sure first.

Here's the Grass Shader : Shader "Custom/Grass" { Properties { _MainTex("Base (RGB)", 2D) = "white" {} } SubShader { Tags { "Queue" = "Geometry" "RenderType" = "Opaque" //"IgnoreProjector" = "True" } LOD 100 Pass { Lighting On Cull Off CGPROGRAM #pragma vertex vert #pragma fragment frag #pragma target 2.0 #pragma multi_compile_fog #pragma shader_feature USE_ARRAY #include "UnityCG.cginc" struct appdata_t { float4 vertex : POSITION; float2 texcoord : TEXCOORD0; uint id : SV_VertexID; UNITY_VERTEX_INPUT_INSTANCE_ID }; struct v2f { float4 vertex : SV_POSITION; float2 texcoord : TEXCOORD0; UNITY_FOG_COORDS(1) UNITY_VERTEX_OUTPUT_STEREO }; sampler2D _MainTex; v2f vert(appdata_t v) { v2f o; UNITY_SETUP_INSTANCE_ID(v); UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o); o.vertex = UnityObjectToClipPos(v.vertex + float3(0, 1, 0) + mul (unity_ObjectToWorld, v.vertex).xyz); o.texcoord = v.texcoord; UNITY_TRANSFER_FOG(o,o.vertex); return o; } float4 frag(v2f i) : SV_Target { float4 col = tex2D(_MainTex, i.texcoord); UNITY_APPLY_FOG(i.fogCoord, col); UNITY_OPAQUE_ALPHA(col.a); return col; } ENDCG } } }

And the Projector Shader : Shader "Projector/Light" { Properties { _Color ("Main Color", Color) = (1,1,1,1) _ShadowTex ("Cookie", 2D) = "" {} _FalloffTex ("FallOff", 2D) = "" {} } Subshader { Tags {"Queue"="Transparent"} Pass { ZWrite Off ColorMask RGB Blend DstColor One Offset -1, -1 CGPROGRAM #pragma vertex vert #pragma fragment frag #pragma multi_compile_fog #include "UnityCG.cginc" struct v2f { float4 uvShadow : TEXCOORD0; float4 uvFalloff : TEXCOORD1; UNITY_FOG_COORDS(2) float4 pos : SV_POSITION; }; float4x4 unity_Projector; float4x4 unity_ProjectorClip; v2f vert (float4 vertex : POSITION) { v2f o; o.pos = UnityObjectToClipPos (vertex); o.uvShadow = mul (unity_Projector, vertex); o.uvFalloff = mul (unity_ProjectorClip, vertex); UNITY_TRANSFER_FOG(o,o.pos); return o; } fixed4 _Color; sampler2D _ShadowTex; sampler2D _FalloffTex; fixed4 frag (v2f i) : SV_Target { fixed4 texS = tex2Dproj (_ShadowTex, UNITY_PROJ_COORD(i.uvShadow)); texS.rgb *= _Color.rgb; texS.a = 1.0-texS.a; fixed4 texF = tex2Dproj (_FalloffTex, UNITY_PROJ_COORD(i.uvFalloff)); fixed4 res = texS * texF.a; UNITY_APPLY_FOG_COLOR(i.fogCoord, res, fixed4(0,0,0,0)); return res; } ENDCG } } }

Thank you for any help provided!